Tandy 1000-series FAQ

Version 2.52

October 25, 2005

Contents

I. Introduction

I.A. Sources and Credits

I.B. What is comp.sys.tandy?

I.C. Where is comp.sys.tandy archived?

I.D. What is an FAQ?

I.E. Where can I get the latest version of this FAQ?

I.F. How can I contribute to the FAQ?

I.G. Help me with my 1000! [no model given] ... And how to tell 1000's apart.

II. Hardware Questions

II.A. Memory

II.A.1. How do I add additional DOS memory to my system?

II.A.2. I added 128k of RAM to my 1000TL, but DOS only gave me 32k more. What happened to the other 96k?

II.A.3. When I boot, it tells me I have 640k of RAM, but Chkdsk says I only have 576k. What gives?

II.A.4. How do I add additional expanded memory to my system?

II.A.5. How do I add additional extended memory to my system?

II.B. Video

II.B.1. Can I install VGA on my system?

II.B.2. I installed VGA, but most programs still think I have CGA. How to I get VGA to work right?

II.B.3. Can I emulate EGA with Tandy video?

II.B.4. What is the difference between a CM5 and a CM11 (or a CM2 or ...)?

II.B.5. What is this weird video Tandy has?

II.B.6. Can I emulate Tandy video with EGA or VGA?

II.C. Floppy Disks

II.C.1. Can I upgrade the BIOS to add high-density floppy drives?

II.C.2. Can I take a floppy drive out of <insert machine here> and use it in my 1000?

II.C.3. Can I take a floppy drive out of my old 1000 and use it in my new 100MHz Pentium?

II.C.4. There's a port on the back for an external floppy drive. Where do I get those?

II.C.5. Where do I get a replacement floppy drive?

II.C.6. My 720k floppy drive formats disks at 360k. What can I do?

II.D. Hard Disks

II.D.1. How can I install a hard drive?

II.D.2. I have a 1000TL/2 with Smart Drive connector on the motherboard. How can I install a drive larger than 40 Meg?

II.D.3. Can I chain two Smart Drives together?

II.E. Keyboards

II.E.1. My keyboard died. Where can I get a new one?

II.E.2. Can I replace my old 90-key Tandy keyboard with a 101-key keyboard?

II.E.3. I can get a standard XT keyboard real cheap. Can I buy/make an adapter to attach it to my old 1000?

II.E.4. How can I make my old keyboard more compatible?

II.E.5. What are the scan codes for the old Tandy keyboard?

II.F. Processors, Coprocessors and Motherboards

II.F.1. How can I increase the speed of the main processor?

II.F.2. Can I install a math coprocessor?

II.F.3. Can I replace the motherboard?

II.F.4. I want to slow my computer down so an old game will run. Where is the turbo switch?

II.G. Serial Ports, Modems, and Mice

II.G.1. Can I use a fast modem with my 1000?

II.G.2. Windows doesn't recognize the mouse on my RLX. What's wrong?

II.G.3. My system doesn't have a serial port. Can I add one?

II.G.4. Can I add another serial port?

II.G.5. What kind of mouse is this, and where do I get a driver for it?

II.H. Parallel Ports and Printers

II.H.1. My printer keeps double-spacing. How do I make it stop?

II.H.2. What kinds of printers can I use with a 1000?

II.H.3. What is the pinout for the card-edge printer connector?

II.H.4. Can I connect my old Tandy printer to my new computer?

II.H.5. Can I use a parallel-port peripheral (other than a printer) with my card-edge printer port?

II.I. Expansion Slots

II.I.1. How can I get standard expansion slots on a 1000HX or EX?

II.I.2. How can I add additional expansion slots?

II.I.3. What kinds of cards will work in the slots on a 1000?

II.I.4. What is the pinout for the Plus expansion connector in the 1000HX and EX?

II.J. Game Ports, Joysticks, and Sound

II.J.1. Can I use a standard joystick?

II.J.2. Can I emulate SoundBlaster with the Tandy DAC?

II.J.3. Can I install a Tandy DAC or 3-voice chip in a normal PC?

II.J.4. What is the pinout for the Tandy joystick?

II.K. Miscellaneous

II.K.1. Radio Shack no longer sells parts for my Tandy. Where can I get them?

II.K.2. When I turn my computer on, it just beeps a lot and refuses to boot. Why does it do that?

II.K.3. Where can I get diagnostic software for the 1000's?

II.K.4. What is this connector marked "light pen"?

II.K.5. I just got a 1000 at a yard sale, and it didn't come with disks or manuals or anything. Where can I get some?

II.K.6. What are the jumper/switch settings for my 1000 or my Tandy adapter card?

II.K.7. I just got a 1000 secondhand, and it has some expansion card in it that I can't identify. How do I find out about it?

II.K.8. When I turn the system on, it just displays the memory size and sits there. What's happening?

III. Software Questions

III.A. DOS

III.A.1. My system has DOS in ROM. How do I upgrade the DOS version?

III.A.2. What are the advantages and disadvantages of upgrading DOS?

III.A.3. How can I change CONFIG.SYS and AUTOEXEC.BAT?

III.A.4. I screwed up my CONFIG.SYS on my hard drive, and now I can't boot the system to fix it - it ignores bootable diskettes!

III.B. DeskMate

III.B.1. My system has DeskMate in ROM. How do I upgrade?

III.B.2. I recently upgraded from my old 1000, and I really miss DeskMate! How can I get it back?

III.B.3. I upgraded my DOS version, and now DeskMate is gone. How do I get it back?

III.B.4. DeskMate Sound and Music won't work when the printer is connected but not turned on. What gives?

III.B.5. How can I write my own programs for DeskMate?

III.B.6. I upgraded my video to VGA, and now DeskMate refuses to run. What do I do?

III.B.7. Is there a program for DeskMate that does (x)?

III.B.8. Where can I get a DeskMate driver for printer (x)?

III.B.9. I just got a 1000. What is this @#&$ "DeskMate" thing it boots into, and how do I get rid of it and run DOS?

III.B.10. I've been using DeskMate on my trusty 1000 for many years, but now it's time to upgrade. How do I transfer the data to Windows?

III.B.11. DeskMate is asking me for a password, and I don't know it. How do I get in?

III.C. Windows

III.C.1. Can I run Windows on my 1000?

III.C.2. Can I run DeskMate under Windows?

III.C.3. Where can I find a Windows driver for my Tandy printer?

III.D. Unix and Other Operating Systems

III.D.1. Can I run Unix on my 1000?

III.D.2. What other operating systems are available?

III.E. ROM BIOS

III.E.1. What is the key combination to bring up the CMOS setup on a 1000?

III.E.2. How do I upgrade the ROM BIOS on a 1000?

III.F. System Setup Programs

III.F.1. I just got an old 1000 secondhand, with no disks or anything. Where can I get the system setup program for it?

III.F.2. What are the options to the system setup command?

III.F.3 Why does my 1000 RLX say I have an invalid configuration?

III.G. Applications

III.G.1. Some compilers do not detect my hardware. Is there an explanation for this?

III.G.2. What C compilers will work on my Tandy 1000?

III.G.3. Where can I find a program for the Tandy 1000 that does (x)?

III.G.4. What games are there for the 1000's?

III.G.5. How can I access the Internet with my 1000?

III.H. Basic

III.H.1. What are the Basic patches?

III.H.2. How do I get information on Basic programming?

III.H.3. What is the "Child of Basic" problem?

IV. Miscellaneous Information

IV.A. How do I contact Tandy?

IV.B. FTP sites, Web pages, BBS's, etc.

IV.B.1. What FTP sites are there for the 1000's?

IV.B.2. What WWW sites are there for the 1000's?

IV.B.3. What BBS's are there for the 1000's?

IV.B.4. What online services had 1000-related areas?

IV.C. What magazines and newsletters are there for the 1000's?

IV.D. What are some good books about the 1000's?

IV.E. What other newsgroups are of interest to 1000 owners?

IV.F. Where can I get other FAQ's?

IV.G. Where can I get upgrade/replacement parts for my 1000?

IV.H. Why is this @#$%!! machine so incompatible?

IV.I. I'm thinking of selling my old 1000, what is it worth?

IV.J. What happened to Tandy?

I. Introduction

I.A. Sources and Credits

The maintainer of this FAQ is Jeff Hayes <tvdog_site@sbcglobal.net>. My sources include the Delphi Tandy forum, the CompuServe TRS-80 Professional forum, the America Online DeskMate and Tandy forums, the comp.sys.tandy newsgroup (and the many knowledgeable people there), some of the books listed in section IV.D, and a few back issues of PCM magazine. Antony D. Gordon was the maintainer for a while, but he's no longer involved with the FAQ. Other contributors' names appear next to their contributions, but I'm afraid I left some people out.

None of this information is guaranteed to be accurate or complete. If the information in this FAQ causes you to reformat your hard drive, blow out your power supply, replace all occurrences of "the" in your dissertation with random expletives, or remember how you were abused as a child and must therefore murder your parents, I am not responsible. Suing me is not a wise proposition anyway since I am poor as a pauper.

I.B. What is comp.sys.tandy?

comp.sys.tandy is a Usenet newsgroup for discussion of any and all Tandy computers, both hardware and software. To get access to the group, you will generally need to have an account at an Internet site that carries the group and some newsreading software. If your site does not carry the group, ask your system administrator or news administrator about adding it.

It is also possible to access Usenet via WWW. Go to this site:

http://groups.google.com/

It is appropriate to post any of the following to comp.sys.tandy: system-specific questions about your 1000 or any other Tandy model; discussions of solutions and workarounds you have found for your Tandy-specific problems; announcements of Tandy-specific hardware or software you have privately for sale, or requests to purchase the same; or basically anything else that is Tandy-specific.

It is not appropriate to post any of the following to comp.sys.tandy: general questions about DOS, Windows, or an application that are not Tandy-specific; general questions about programming PC-compatible computers or using your compiler; and general questions about IBM PC hardware. There are other newsgroups for discussion of those things (and plenty of books on them). If you have a problem and are not sure whether it is due to a compatibility problem with your machine, you can ask in comp.sys.tandy; if your problem is a general one, you will probably be referred elsewhere.

Bear in mind that some TRS-80 owners flat don't like PC's. They will often say that something can't be done when it can, just because they hate the 1000's. They will insult the PC-compatible Tandy's for no reason (comp.sys.tandy is probably the only group where participants actively discourage people from using the hardware the group is devoted to). It may be better to go to the Yahoo group to ask your question:

http://groups.yahoo.com/group/Tandy1000/

I.C. Where is comp.sys.tandy archived?

Google has messages going back to 1987:

http://groups.google.com/

I.D. What is an FAQ?

An FAQ (short for "frequently asked questions") is a compilation of information frequently asked for and given in a newsgroup. It also usually states the newsgroup's purpose and the etiquette to be followed when posting. Its purpose is to improve the signal-to-noise ratio in the group by reducing repetitive threads and eliminating flame wars caused by breaches of etiquette. The FAQ is usually in question-and-answer format.

comp.sys.tandy does not have a bandwidth problem, but an FAQ for the 1000's is still useful, just to keep all this information in one place.

I.E. Where can I get the latest version of this FAQ?

You've got it. There are no plans to make a newer one.

I.F. How can I contribute to the FAQ?

Send your corrections and additions to <tvdog_site@sbcglobal.net>. Where possible, refer to the section number that contains the mistake or omission. Note, however, that there might not be any more updates except to correct something that is glaringly wrong.

I.G. Help me with my 1000! [no model given] ... And how to tell 1000's apart.

You won't get much (useful) help if you post a question in comp.sys.tandy saying, "Such-and-such won't work on my Tandy 1000, what do I do?" The 1000-series range from the original 1000, which came standard with a 4.77MHz 8088, PCjr-compatible graphics, and 128k RAM, to the 1000RSX, which came standard with a 25MHz 80386SX, SVGA graphics, and can be upgraded to 9 megabytes of RAM (1 meg standard). You have to tell us which model 1000 it is. The choices are (in more-or-less chronological order): original 1000 (no letters), 1000A, 1000HD, 1000EX, 1000SX, 1000AX (rare, mostly the same as the SX), 1000HX, 1000TX, 1000SL, 1000PC (rare, mostly the same as the SL), 1000TL, 1000SL/2, 1000TL/2, 1000TL/3, 1000RL, 1000RL-HD, 1000RLX, 1000RLX-HD, 1000RLX-B, 1000RLX-HD-B, 1000RSX, and 1000RSX-HD. In the following, I often refer to "TX and earlier" and "SL and later." The later ones are much more compatible with the IBM PC - the earlier ones are more compatible with the IBM PCjr (see section IV.H.). I will also abbreviate the names - "TL" means 1000TL; "TL/2" means 1000TL/2; and "TL's" means 1000TL, 1000TL/2, and/or 1000TL/3.

II. Hardware Questions

II.A. Memory

II.A.1. How do I add additional DOS memory to my system?

On the 1000 and 1000A, you need to add an expansion card. This card will contain both additional RAM and a DMA chip, improving the speed and compatibility as well as the memory size. Tandy used to sell such a card, as did many other companies.

The EX and HX will also need an expansion card, one made for their slots. One or more additional PLUS-type slots may also come with the memory expansion. Tandy used to sell a memory card for these systems too.

The other systems will only need standard DRAMs. It is OK to use faster chips than required (i.e., 100ns instead of 120ns).

The SX will take 8 256k x 1 150ns DRAM chips. The chips go behind the other RAM chips near the front of the machine. You also need to remove the jumper labelled E1-E2.

The TX uses 4 64k x 4 120ns DRAM chips. The chips go in the sockets labelled U54-57. Remove the jumper labelled E9-E10.

The TL uses 4 64k x 4 120ns DRAMs. The chips go in the sockets labelled U36-39. There is no jumper to move.

The TL/2 uses 4 64k x 4 120ns DRAMs. The chips go in the sockets next to the other RAM chips, in front of the expansion slots. There is no jumper.

The TL/3 uses 4 64k x 4 100ns DRAMs. The chips go in the sockets labelled U4-7. There is no jumper.

The SL uses 8 64k x 4 120ns DRAMs. They go in the sockets next to the other chips. There is no jumper.

The SL/2 uses 4 64k x 4 120ns DRAMs. They go next to the other chips. There is no jumper.

The RL and RL-HD use 2 256k x 4 100ns DRAMs. They go in the sockets labelled U19 and U23. There is no jumper.

The RLX uses 4 256k x 4 100ns ZIP DRAMs. This not a common type of chip. They go in the sockets labelled U23-26. There is no jumper.

The RLX-B uses 4 256k x 4 100ns ZIP DRAMs. They go in the sockets labelled U2, U4, U5, and U9. There is no jumper.

The RLX-HD, RLX-HD-B and RSX's came from the factory fully populated with conventional RAM.

ZIP DRAMs for the RLX are hard to find. You are looking for Samsung chip #KM44C256AZ-8. For regular DRAM chips, see section IV.G.

II.A.2. I added 128k of RAM to my 1000TL, but DOS only gave me 32k more. What happened to the other 96k?

II.A.3. When I boot, it tells me I have 640k of RAM, but Chkdsk says I only have 576k. What gives?

All of the 1000-series except for the 1000RLX's and RSX's have special video controller circuitry that allocates some of the video memory for DOS if there is less than 640k of conventional RAM installed. The video controller has 128k or 256k (depending on the model), which is more than it really needs under most circumstances, since CGA programs only use 16k, and even most programs that use the special Tandy video modes only use 32k (Hercules mono graphics also requires 32k). About the most that is ever used is the 64k that the special 640x200x16 video mode on the 1000SL's, TL's, and RL's requires. (All video RAM could conceivably be used by some programs for animation.)

The original 1000 was a clone of the IBM PCjr (see section IV.H.). The PCjr came with 128k RAM that was both video RAM and system RAM - whence the 128k attached to the video controller. Among other things, this enabled IBM to leave out the DMA controller the IBM PC had, since the RAM was continually being refreshed by the video controller. The original 1000, 1000A, 1000EX, and 1000HX have no DMA controllers on the motherboard either (one is included with the memory expansion card). Tandy added a DMA controller to later systems, but the video stayed the same, at least at the BIOS and memory-mapping level, up till VGA was added with the RLX. On Tandy's with PCjr-compatible video, that 128k or 256k is still both video and system RAM - and since not all of it is normally needed for video, part of it is normally "stolen" by DOS, up to a limit of 640k system RAM.

When the BIOS displays the system memory at bootup, it's telling a little white lie, since it includes the video memory in the total. There is, after all, no way to know who owns what memory, DOS or the video, so it is all lumped together. You can change the amount that the video keeps for itself with the /A option on your system setup program, if you have it (see section III.F.2.). (There is also a shareware program called Adjmem that can change the amount at runtime.)

When you install additional conventional memory in your system, whatever video memory was being "stolen" by DOS goes back to the video, if DOS has 640k. The amount of DOS RAM you gain by the upgrade thus may not be equal to the amount of RAM you install, since whatever was stolen before is lost. There is no way to make the Tandy BIOS allocate more than 640k for DOS, and no way to do it by programming either.

If you are still using the built-in video, the memory upgrade is definitely worthwhile since every byte of conventional RAM counts. If you upgrade the video, though, all of the motherboard video RAM will go to DOS to make up whatever is missing from 640k. VGA (and EGA) cards have their own memory, so they don't need what's on the motherboard. With VGA, in a sense it is useless to expand your total system RAM beyond 640k on these systems; as far as I know, there is no program available that will make any use of the motherboard video RAM on a 1000TL with 768k and VGA (my program Vswitch will allow you to use both VGA and the motherboard video).

One thing to note, however: some programs (such as Windows 2.11) and expansion cards (such as Acculogic and Intel EMS cards) may not work properly without the extra 128k memory upgrade, even if VGA is installed. There are two causes for this: First, the RAM that is "stolen" by DOS from the video is actually accessed through the video controller, making it slower than the rest of system RAM; time-critical things like sound programs are affected by that. Second, an LIM 4.0 EMS driver may "see" that there is, say, 576k system RAM, and erroneously conclude that the memory between 576k and 640k is available to be mapped as EMS, when in fact part of it is double-mapped video memory (the double-mapping is another PCjr fossil). Hence, it is a good idea in any case to add as much motherboard memory as your system will take - which on most 1000's is quite cheap to do these days.

II.A.4. How do I add additional expanded memory to my system?

On older 1000's (i.e., pre-SL) with standard slots, four EMS cards will work: the Micro Mainframe 5150T, the Intel Matched Memory Classic, the Intel Above Board ISA, and the InvisiSOFT Invisible EMS board. The latter three are hardware LIM 4 and can be used for upper memory blocks with DOS 5 or 6 (possibly requiring Qram or equivalent); the 5150T does not supply upper memory blocks. Upper memory blocks may not be available on systems with DOS in ROM, even if DOS is upgraded, because the memory segment (E0000h) that would be used as an upper memory block by the EMS card is already occupied by the ROM drive (whether the ROM drive is accessed or not).

A few multifunction cards were made for the original 1000, A, and HD that had expanded RAM as an option. The PBJ XRAM card was another EMS card that would work in those systems.

The EX and HX will need a special EMS card because of their nonstandard slots. (With those systems, conventional RAM and EMS may be added on the same card.)

Lloyd W. Kuhn writes:

Some years ago I put an Intel expanded memory board in my TL, but I had a heck of a hard time getting the Intel software to configure the board to the computer. I called Intel and although they they tried, they couldn't help me. Because the TL has an 80286 processor, the software tried to make the computer out as an AT clone. But when the software sensed the 8 bit expansion slots, it was sure the computer was an XT clone. Therefore I couldn't configure it as an AT nor as an XT. However out of frustration, I tried configuring the TL as an IBM model 30. That worked and the board has been working ever since.

The SL's, TL's, RL's, and RLX's can use any 8-bit expanded memory card that is 10" or less in length. The RSX's do not need expanded memory; use extended.

II.A.5. How do I add additional extended memory to my system?

The RLX's can have 384k of extended RAM, installed at the same time as you upgrade the conventional RAM (see section II.A.1.). The RLX-HD and RLX-HD-B came fully populated with 1M system RAM, though.

You add RAM to the RSX by putting either 2 70ns 1Mx9 SIMMs or 2 60ns 4Mx9 SIMMs in the empty sockets. See section IV.G. for sources. You have to run Setuprsx after installing to make the system recognize the new memory.

If HIMEM.SYS does not recognize your extended memory, use the /M:2 option.

None of the other 1000's can have extended RAM.

II.B. Video

II.B.1. Can I install VGA on my system?

On the original 1000, 1000A, and 1000HD, no. On those systems, the BIOS will not scan for a video ROM or disable the onboard video. Matthew Electronics once manufactured a special EGA card for the original 1000, A, and HD, but it is no longer available. That said, it is generally possible to get a standard EGA card to work to some degree if you make a program for AUTOEXEC.BAT to enable it; see file
ftp://ftp.oldskool.org/pub/tvdog/tandy1000/documents/egat1k.txt

One other problem you are likely to have is that an EGA card will want to use IRQ 2 for vertical retrace, which conflicts with the hard drive; you need to have a hard drive controller that does not use an IRQ (or do without a hard drive). Upgrading the video on the original 1000, A, or HD is definitely a "hacker upgrade."

The EX and HX can have VGA but will need a special card because of their nonstandard expansion slots. The SX and TX need to have DIP switch 1 turned off. The SL's, TL's and RL's won't require any hardware changes; just plug in the card.

The RLX's and RSX's came standard with VGA. Both can accept upgrade video cards as well.

All 1000's that don't come standard with VGA will require that a special program be placed in AUTOEXEC.BAT to make sure the new video is recognized (see section II.B.2.).

II.B.2. I installed VGA, but most programs still think I have CGA. How do I get VGA to work right?

The Tandy BIOS fails to set the Video Configuration Code byte at 0040:008A. The default value of this byte is 3Fh. The correct values are: 0Bh, for a single VGA color card; 0Ch, for a dual-monitor system with VGA color and MDA mono; 0Dh, for a single VGA mono board; and 0Eh, for a dual-monitor system with mono VGA and MDA. The solution is to put a short program in your Autoexec.bat file that will set this byte to the correct value. Without the fix, the VGA card will function, but some programs will misidentify it as EGA or CGA. There are various programs around to do this. Radio Shack included one with their version of the Paradise card, and if you got your VGA card from a place that specializes in 1000's, they would have given you one.

There are free programs available to fix these problems. Get vgafix.zip, for example. (See section IV.B.1. for a site).

II.B.3. Can I emulate EGA with Tandy video?

No. Although the SL's, TL's and RL's have a 640x200x16 video mode that is similar in resolution to EGA, the register programming and memory mapping are different. The same applies vis-a-vis the 320x200x16 video mode that all 1000's (except the RLX's and RSX's) have.

II.B.4. What is the difference between a CM5 and a CM11 (or a CM2 or ...)?

The CM5 and CM11 are both CGA monitors. The difference is the resolution. The CM11 is much clearer due to its smaller dot pitch (and was about half again as expensive as the CM5). Some say the CM5 can't display 640x200 graphics. That is a function of the controller, though, not the monitor. The CM5 will work in all Tandy graphics modes. Whether it looks good is another story. The CM2 and CM10 are older versions of the CM11. The CM4 is an older version of the CM5.

The CM1 is another animal entirely. It was a color monitor made for use with the Tandy 2000 and had a resolution of 640x400. Tandy made at least three video cards that would permit the CM1 to be used with an IBM PC. With the Deluxe Text Display Adapter, catalog number 25-3046, the CM1 displays only text. With the Deluxe Graphics Display Adapter, catalog number 25-3047, the CM1 can display CGA-compatible 640x200 graphics, or 640x400 graphics with special software. With the Enhanced Graphics Adapter, catalog number 25-4037, the CM1 displays 640x350 EGA graphics. The VM1, a monochrome monitor for the 2000, works with the same cards.

The CM8 is only for use with the Color Computer; there is no adapter card for an IBM PC.

The VM2 and VM4 are monochrome composite monitors made to plug into the composite CGA port on the original 1000, HD, A, HX, EX, SX, and TX.

The VM3 and VM5 are monochrome TTL (MDA/Hercules) monitors. They can be used with the 1000SL's, TL's, and RL's.

The EGM1 is an EGA monitor. VGM* are VGA or SVGA monitors.

You do not have to use a Tandy monitor; any CGA monitor will work. If you have problems centering the screen with a non-Tandy CGA monitor, try "MODE 200" at the DOS prompt (Tandy DOS only). One non-standard thing that Tandy did was to use 225 scanlines for text modes in CGA, giving somewhat clearer text. IBM standard is 200 scanlines.

II.B.5. What is this weird video Tandy has?

The original 1000 was a clone of the IBM PCjr (see section IV.H.). The PCjr video is BIOS- and memory-mapping compatible with CGA, though not register-compatible. It also has 160x200x16, 320x200x16, and 640x200x4 video modes that CGA does not have. Most programs using CGA video modes use the BIOS to interface with the video adapter (except for setting pixels) and will work. Pre-SL systems have this type of video, also known at Tandy Video I, TGA, TCGA, or ECGA. Digital or composite CGA monitors can be used (the composite output can also be connected to the RCA jack on a TV set). Some of the books in section IV.D. contain programming information on Tandy 1000/PCjr video.

The video on the SL's, TL's, and RL's is known as Tandy Video II or ETGA. The video adapter takes either a digital CGA or Mono TTL monitor; pressing <alt>-<control>-<shift>-V reboots the system and switches monitor types, saving the type in EEPROM. When a Mono TTL monitor is used, the video is compatible with the Hercules adapter. When a CGA monitor is used, the video is register-compatible with CGA and BIOS- and memory-mapping compatible with PCjr. Any program using CGA will work, and most (but not all) programs using PCjr video will work. This adapter also has the 160x200x16, 320x200x16, and 640x200x4 modes of Tandy Video I, as well as a 640x200x16 mode (the BIOS does not support this mode - you need to program controller registers to get it or use a TSR such as grafix.zip (see section IV.B.1. for a site)). The technical reference manual for your system has information on ETGA (see section IV.D.).

The RLX's have basic (256k) VGA built in; it is not upgradeable. The RSX's 256k VGA is upgradeable to 512k and can display 1024x768 with an appropriate monitor. Both can display Hercules graphics on a VGA monitor.

Most systems can also take upgrade video cards (see section II.B.1.).

II.B.6. Can I emulate Tandy video with EGA or VGA?

Yes, if you have a 386 or above. Get the Tand-em emulator from the emulators directory on the Tvdog site (make sure you get the ROM image also). There are other Tandy 1000 emulators out there as well. (If you're trying to make DeskMate work with EGA or VGA, see section III.B.6.)

II.C. Floppy Disks

II.C.1. Can I upgrade the BIOS to add high-density floppy drives?

The TL/3, RLX's, and RSX's can take high-density drives, though the TL/3 did not come with one. The RLX will not take low-density drives.

Other models require that a secondary controller be installed in an expansion slot to add high-density drives. There was a rumor that an AMI or Phoenix BIOS upgrade for the IBM XT could be used in a Tandy 1000-series, permitting high-density drives to be used with the built-in controller, and providing BIOS support for hard drives. The rumor was false. In most 1000-series, the built-in controller cannot support high-density drives because the data separator will only run at 250k bps. In the SL and TL, the data separator is capable of running at 500k bps, but the data rate pin is hard-wired to 250k and the drive speed pin on the floppy cable is not connected. In addition, an IBM BIOS chip would not support Tandy-specific features such as the weird video memory mapping and the digitized sound functions on the SL/TL. Tandy says:

Tandy Corporation/Radio Shack does not support installing a high density drive in your Tandy 1000TL computer as the on-board Floppy Drive Controller (FDC) circuitry is not designed to work with this type of drive. The FDC circuitry only has the capability of recognizing a low density disk drive.

As well, since the FDC circuitry has no option for being disabled through jumpers or dipswitches, this circuitry cannot be changed to setup as the secondary address. The BIOS ROM does not support a secondary FDC address, thus precluding the installation of a controller card set to the secondary address.

THANK YOU,
RADIO SHACK COMPUTER SUPPORT SERVICE CC/dp

Of course, this is just another case of "we don't sell it, therefore it can't be done." In reality, there were secondary cards available that contained their own BIOS, providing either bootable or non-bootable high-density drives (see section IV.G.). These would have been specially made for Tandy.

If you have a (standard) controller with its own BIOS, the following program can disable the onboard controller (on SL and later systems only):

ftp://ftp.oldskool.org/pub/tvdog/tandy1000/utilities/nofloppy.zip

Obviously, you need to have a hard drive for this to work, since the I/O port conflict with the built-in controller will prevent the floppy drive from working until the built-in controller is disabled from AUTOEXEC.BAT.

The TX and earlier systems may require special secondary controllers to add a high density drive.

II.C.2. Can I take a floppy drive out of <insert machine here> and use it in my 1000?

If it's a 5-1/4" drive, generally yes. Note that the data connector may be upside down. It needs to be the right-density drive for the machine.

For 3-1/2" drives, maybe. The HX, TX, SL/2, TL's, RL's, RLX's, and RSX's use a special floppy drive that draws power through the data cable. Connecting a standard 3-1/2" drive not designed to do that can damage both the drive and the computer. If your existing floppy drive does not have a four-wire (red, red, black, yellow) power cable going to it, you MUST NOT replace it with a standard drive (unless you modify the floppy cable, see below). Tandy-style drives were made by Panasonic, Teac, and Sony. Here are some low-density ones:

Sony MFD-63W-70D
Sony MP-F11W-71
Sony MP-F11W-72
Sony MP-F11W-72D
Sony MP-F63W-01D
Teac FD235-136U
Teac FD235F-105U
Teac FD235F-106U

And here are some high-density drives:

Panasonic JU-257A213P
Sony MFD-17W-72
Sony MP-F17W-70D
Sony MP-F17W-71
Sony MP-F17W-72
Sony MP-F73-70D
Teac FD235HF-106U

Tandy continued using the drives long after the 1000-series ended (my 4033LX had one in it - high density of course).

In the case of systems with drives that draw power through the data cable, you can connect a standard drive if you modify the cable. You need to punch holes in the data cable to cut the power; look at the 5-1/4" cable in the same machine. Specifically, +5V is supplied on pins 3, 5, 7, 9 and 11, and +12V is supplied on pins 29, 31, and 33. All of these are ground pins on a standard floppy cable, so you need to cut them. Use a Tandy-style (straight-through, not twisted) floppy cable, like the original that came with the machine. NOTE: If you don't feel confident about modifying your floppy cable in this way, don't. If you make a mistake, you can blow out your power supply, your motherboard, your floppy drive, or all three.

To fix the cable, extract the wires you need to cut by cutting the cable lengthwise between the wires with a utility knife, taking care not to cut the wires themselves. Pin 1 is marked on the cable in red. On a standard floppy drive, all the grounds are connected together, so you don't need to worry about connecting an actual ground wire to the pins you cut. If you want to continue to use a Tandy drive in the same machine, place the standard drive at the end of the cable and the Tandy drive in the middle, and make the cuts above the connector for the Tandy drive, so that the power coming from the motherboard gets to the first (Tandy) drive but not to the second (standard) drive. Of course, you need to connect a power cable to the standard drive.

Another problem you might have with 3-1/2" drives is that the drive may not physically fit in the machine due to the placement and length of the eject button, since the drive bezel is built in to the case. If that is so, some people cut away the built-in drive bezel with a hacksaw to make a "standard" drive bay.

Finally, note that unlike most every other PC, the floppy cable in the 1000-series is not twisted, so you need to set the drive select jumper or switch on the drive. Be aware that some newer drives don't have a drive select jumper (in a Tandy, you could only use them as drive A:). Also, if you put a high-density 3-1/2" drive in a machine that doesn't support one, it works, but only as a low-density drive.

II.C.3. Can I take a floppy drive out of my old 1000 and use it in my new 100MHz Pentium?

Some 1000's use special floppy drives that draw power through the data cable, so it may take some hardware hacking to do this. The 3-1/2" drives are the culprits. See section II.C.2. A dead giveaway for a Tandy drive is that it has no power connector (there are some that do have a power connector, however - beware).

What you would need to do to put a 3-1/2" Tandy-style drive in a standard machine is cut out the wires in the data cable that the Tandy drive wants power on, disconnecting them from the motherboard, then solder the wires to a power cable. The red wire on the power cable is +5V, the black is ground, and the yellow is +12V.

II.C.4. There's a port on the back for an external floppy drive. Where do I get those?

The 1000EX and HX had this port. There was a 360k external drive, catalog number 25-1060, and a 720k external drive, catalog number 25-1061. Check eBay for them and see section IV.G.

II.C.5. Where do I get a replacement floppy drive?

The following systems use special 3-1/2" 720k floppy drives that draw power through the data cable: 1000HX, RL's, RLX's, RSX's, SL/2 (drive A: only), TL's, and TX. You must replace those drives with another Tandy-style drive. No company, to my knowledge, has Tandy-style floppy drives for sale any more. As with systems that use the old Tandy keyboard (see section II.E.1.), probably the best way to get a replacement is to buy another whole system that has the drive you need in it; 1000-series systems are found for sale on eBay routinely.

The original 1000, A, HD, EX, SX, and SL use standard 360k floppy drives. Computer Reset still sells them; see section IV.G. You might need to replace the floppy cable if you replace the drive.

The RLX's and RSX's use 1.44M floppy drives that draw power through the data cable. Like the 720k versions, these Tandy-style drives are no longer available. Tandy used these type of drives in many later models, so you can probably find a system for sale on eBay that has the drive you need (check the Radio Shack support site to find out the specifications for a given system).

II.C.6. My 720k floppy drive formats disks at 360k. What can I do?

This can happen if you upgrade the DOS version (see section III.A.2.), or after adding a 720k drive to an older system that didn't come with one. Use the DRIVPARM command in CONFIG.SYS:

DRIVPARM=/D:0 /F:2 /H:2 /S:9 /T:80

(For drive A: - drive B: is /D:1, etc.) If that doesn't work, try DRIVER.SYS instead:

DEVICE=DRIVER.SYS /D:0 /F:2 /H:2 /S:9 /T:80

DRIVER.SYS will create a new drive letter, while DRIVPARM will not - see your DOS manual. There are also third-party utilities to deal with this situation, for example:

ftp://ftp.oldskool.org/pub/tvdog/tandy1000/utilities/setbpb.zip

Note that you must be running DOS 3.2 or later for any of the above to work. If you are still using 2.11, it is time to upgrade. Get the SX disk set from the system directory on the Tvdog site for Tandy DOS 3.2.

II.D. Hard Disks

II.D.1. How can I install a hard drive?

It depends on which model 1000 you have.

The 1000RSX has a built-in AT IDE interface, a very common type of drive. An IDE drive of 504MB or less should work. You could also use one of the two 16-bit expansion slots for a SCSI controller and install a SCSI drive up to 8GB. Larger drives might work too, perhaps with partitioning software provided by the drive manufacturer.

The TL/2, TL/3, RL's, and RLX's have a built-in XT IDE ("Smart Drive") interface. These drives are hard to find nowadays and don't come larger than 40MB. AT IDE drives (what everybody means when they advertise IDE drives for sale) do not work with the built-in interface. Tandy once sold a full line of XT IDE drives. Other vendors also once carried the drives. Here is a list of some XT IDE drives:

Miniscribe M8225XT
Miniscribe M8450XT
Seagate ST351A/X (combination XT/AT IDE)
Seagate ST325X
Seagate ST325A/X (combination XT/AT IDE)
Seagate ST351X
Western Digital WD93028
Western Digital WD98028
Western Digital WD93038-X
Western Digital WD93044-X
Western Digital WD98044-X

If your drive doesn't appear to fit in the drive bay of your RL or RLX, remove the drive bracket and turn it upside down. There can be a problem with 40MB drives in the RL, in that it refuses to recognize more than 20MB of the drive (a 40MB drive worked with no problems in my RL, however).

If you bought your XT IDE drive at Radio Shack, it would come with an installation diskette. Systems with "Smart Drive" interfaces also came with various programs to simplify installation. The normal way to install a hard drive on these systems was to run HINSTALL.PDM from inside DeskMate and follow the prompts. I think if you just plug it in and use FDISK and FORMAT like a normal drive it will work, though. These systems have DOS in ROM. If you want to boot from the hard drive, you will need to run the system setup program and set the computer to boot from DISK with MS-DOS as the startup program.

Tandy DOS comes with a program called HSECT. Do not use it on XT IDE drives; it will render them unusable. AUTOFMT, another Tandy DOS program, is a front end for HSECT and should not be used either.

Tandy provides the following information on adding an XT IDE "Smart Drive" to a 1000RLX that did not come with one (the information should be relevant for other models):

If you choose to add a SmartDrive to your floppy RLX computer later, you'll find the installation a very easy task. The 20 (25-1047) and 40 (25-1048) Megabyte SmartDrives feature the HINSTALL initialization program that runs under DeskMate. Four keystrokes and you're finished. Even a labeled blank diskette is included! The MS-DOS/GW-BASIC diskette installs to the SmartDrive under DeskMate as well. Just start DeskMate, press <F7>, highlight INSTALL, put your MS-DOS/GW-BASIC diskette in Drive A, and MS-DOS is installed in its own directory. It even creates or modifies the AUTOEXEC.BAT file and sets the ROM.

You can install another type of controller in an expansion slot if you have a built-in Smart Drive interface but can't find a drive for it. MFM and RLL controllers will not work in the TL/2. Only Seagate MFM/RLL controllers will work in the TL/3. Only Western Digital MFM/RLL controllers will work in the RL or RLX's. The ADP50T will work in any model with built-in Smart Drive controller (see below). Some 8-bit SCSI controllers will probably work also, though the Seagate ST01 will not (it works in other 1000-series models). An add-in controller installed in a 1000TL/2 or TL/3 should have its ROM address set to CC00h or CE00h to avoid conflict with the built-in controller at C800h.

Radio Shack sold a hardcard with an 8-bit AT IDE controller for the 1000's, catalog number 25-1095, for $99. The card does not conflict with the built-in controller in the TL/2, TL/3, RL's, and RLX's. Regarding the RL, a poster in comp.sys.tandy wrote:

For the RL, you have to <argh> cut away a little of the bracket that comes with it or it will hit the motherboard. It says that it is not recommended for the RL, but that is only because of the size problem ... about 5 minutes of cutting, and it will work just fine.

Like other hardcards, the 25-1095 card is very wide and needs to be placed in the innermost expansion slot, or it will take up two adjacent slots. It will not fit in a 16-bit slot.

The 1000SX, TX, SL's, and TL can use most standard 8-bit hard drive controllers. The SX and TX will need DIP switch 2 on the motherboard turned off to allow the hard drive to use IRQ 5 as is standard for XT-class systems. The Western Digital WD1004 will not work in the SL or SL/2. Otherwise, most any MFM or RLL controller will work.

Tandy marketed an XT IDE controller card that could be used in an 8-bit slot, cat. no. 25-1088, but that's really not a practical way to go unless you already have the drive for it (see list above). The card will not work in the TL/2 or TL/3 (which have a built-in XT IDE interface and don't need it anyway).

The Silicon Valley ADP50T ("T" for Tandy BIOS, ADP50 is not the same) is good 8-bit AT IDE card that cooperates with your existing XT IDE drive, if any, and can chain two AT IDE drives (if they are from the same manufacturer). It works in all models of the 1000-series, including the original 1000 with BIOS version 01.00.00. It does not work with Quantum drives, however. The Tandy version of the ADP50 card has BIOS version 2.18T on it. There are some instructions for the ADP50T and a list of drives compatible with it here:

ftp://ftp.oldskool.org/pub/tvdog/tandy1000/documents/adp50.zip

The original ADP50 will also work in the 1000's, but only with Conner and Fujitsu drives (refer to list above). It is jumpered differently than the Tandy version; see:

ftp://ftp.oldskool.org/pub/tvdog/tandy1000/documents/adp50l.zip

Acculogic also made an 8-bit AT IDE controller (the 1/16). It required a special modification to work in the 1000-series (according to Upgrading Your Tandy), but if so modified it worked well (see below). Also, as noted above Radio Shack once sold an 8-bit AT IDE controller for the 1000's. Never low-level format an IDE drive.

8-bit SCSI controllers can be used also; check eBay for them. You shouldn't try to connect too large a drive to an 8-bit SCSI controller (check to see how large a drive it will support). And don't low-level format a SCSI drive either.

As with the TL/2, TL/3, RL, and RLX's, if you want to boot from the hard drive in the SL's or TL you will need to use the system setup program to configure the system to boot from DISK and have MS-DOS as the startup program.

The original 1000, A, and HD have a standard 8-bit slot connector but use IRQ 2 for the hard drive interrupt. Only controllers that can be set to IRQ 2 can be used, and these are few and far between. (The 1000SX and TX are also set to use IRQ 2 for the hard drive as they come from the factory, but in their case you can turn DIP switch 2 off on the motherboard and use a standard controller - see above.)

The original 1000 and 1000A will need to have the memory expanded above 128k to add DMA to the system before a hard drive can be installed. The DMA chip is included on the memory expansion card.

The original 1000 may need a BIOS upgrade before installing a hard drive - see section III.E.2. FYI, the problem is that the BIOS programs the DMA controller for extended write cycles rather than normal write cycles, causing timing problems. Two changes to BIOS version 01.00.00 would correct the problem:

   Address              Current byte            Correct byte
   F000:C7B7                 24                      20
   F000:C7FC                 20                      00

(All numbers are hex.) Alternately, two instructions added to the hard drive controller BIOS would work around it:

   XOR    AL,AL
   OUT    8,AL

Tandy once offered to take the Memory Plus expansion adapter back and replace the PAL chip (U14) to correct the problem. Tandy no longer sells either the BIOS upgrade or the PAL chip. If you have the old BIOS version, you can still have a hard drive, it just won't be bootable (you will have to boot from floppy).

T.J. Harrell says that he had an Acculogic sIDE 1/16 controller that worked in the original 1000 with 128k and with BIOS version 01.00.00. He writes, "The card was supposed to have jumpers to select between IRQ2 and IRQ5, but the jumpers were missing and the board wired for IRQ5. Cut that trace, short the IRQ2 jumper pads, and *bingo*." The card also worked in the 1000TX. He used it with a Conner IDE drive.

The Seagate ST11M was an MFM controller that would work on IRQ 2; the ST11R was the RLL version. The 1000's Tech Notes and Jumper Manual says they required modification to be used on the original 1000, while Upgrading Your Tandy says they didn't, so I'm not sure what to think. There were several BIOS versions for these autoconfigure controllers, so perhaps that is it. The ST11M/R seem to be the only MFM/RLL controllers that might work without modification, though there were several Western Digital controllers that could be modified to use IRQ 2: WD1002-WX1, WD1002-WX2, WD1004A-WX1, WDXT-GEN2, and WD1004-27X. In some cases a special Tandy ROM was also required, and of course you can't get those any more, but if the card came out of a Tandy, it would already have the mods applied. Tandy sold several different "hard cards" for the original 1000 and 1000A using the above controllers as well as IDE; these hard cards come up for sale on eBay occasionally:

25-1029/A/B (20MB MFM)
25-1032/A/B (20MB MFM)
25-1032C/D/E/F (20MB IDE)
25-4059/A (40MB RLL)
25-4059B (40MB IDE)

The Silicon Valley ADP50T AT IDE controller will work on IRQ 2, as will the original ADP50, though the latter supports fewer drives; see above.

The 1000EX and HX have Plus-type expansion slots rather than a standard 8-bit slot connector and use IRQ 2 for the hard drive interrupt. They can use the same hard drive controllers as the original 1000, A, and HD, but you will need to make a slot adapter for them first - see section II.I.1. Some companies sold controllers for the EX and HX with a slot adapter already attached. Like the original 1000 and 1000A, the EX and HX will need to have the memory upgraded above the base configuration (256k in their case) to install a hard drive since the required DMA chip is included on the memory expansion card.

The EX does not have space in the case to install a hard drive; it will have to be mounted externally and grounded to the case with a grounding wire. You can get power to the drive by attaching a power splitter cable to the 5-1/4" floppy power cable. The HX has an available drive bay that can be used for a 3-1/2" hard drive, but it has no power cable. You can wire one up by cutting into the motherboard power leads and soldering in a connector. Various companies sold external drives for the EX and HX to overcome these problems.

Regardless of which model 1000 you have and which controller you use, it is important to remember that any controller will need a drive appropriate for it. On an XT-class system, the BIOS hard drive support is on the controller card, not in the system BIOS. Any drive you use with a given controller will have to be supported by that controller. Check the controller's documentation online to find out what drives it supports (cylinders, heads, sectors), then find a drive to match. AT IDE and SCSI controllers tend to support more different drives than MFM or XT IDE. If at all possible, buy the drive and controller at the same time from the same company or person to make sure they will work together.

Various hard drive utilities may be used to set up a hard drive; some came with Tandy DOS, some on a separate utilities disk included with the drive:

AUTOFMT: This program used with Tandy hard cards low-level formats the drive, then high-level formats it. It is a front end for several other programs (HSECT, FDISK, and FORMAT). Don't use it unless you are told to.

HFORMAT: The Tandy DOS 2.11 FORMAT program can only format floppy drives. To format a hard drive, use HFORMAT. It came on a separate "hard drive utilities" disk, not with DOS.

HSECT: This is a low-level formatting utility for Tandy drives. Use it only if the drive's installation instructions tell you to. It is only used with certain MFM and RLL drives.

LLFORMAT: Tandy DOS 3.2 has LLFORMAT instead of HSECT as a low-level formatting utility. Don't use it unless you are told to do so.

MLPART.SYS: MS-DOS prior to 3.3 does not support multiple hard drive partitions. Tandy DOS 3.2 does. First use FDISK to create the C: partition, then use MLPART.COM to create addtional partitions. MLPART.SYS (loaded in CONFIG.SYS) provides access to partitions other than C: on a hard drive with multiple partitions. MLFORMAT was the program used to format the additional partitions.

The low-level formatting utility may offer an option to "virtually" partition the drive for use with DOS 3.2 and below that do not directly support multiple partitions. Tandy DOS 3.3 will run on any model and supports multiple hard drive partitions with standard FDISK and FORMAT. If you are installing a hard drive and have a lower DOS version, you might consider upgrading - get the TL disk set from the system directory on this site.

It is reported that some software will not work properly with Tandy hard cards if you have Tandy DOS below 3.2.

Some people think they can't install a drive and controller and need a "hardcard" instead, because the owner's manual mentions the latter and not the former. A hardcard is just a controller and drive combination mounted on a card, though, and some companies sold brackets that enable a person to make their own hardcard out of a controller and a 3-1/2" hard drive. Beware that the 1000's have shorter slots than the IBM XT - if you get a hardcard, it needs to be specially made for the 1000's. In some cases you may find that the system doesn't supply enough power to operate a hard drive through the expansion bus (i.e., using the power connector on the controller card) - connect power to the drive directly from the power supply.

If you are out of drive bays, it may be possible to install a hard drive by attaching it to the bottom of an existing bay with Velcro. A hard drive can be installed externally as well, but you must use a ground wire to ground it to the computer's case; you will get errors if the drive isn't properly grounded.

If you get a hard drive, you should make it bootable even if you don't plan to boot from it, in case you decide to upgrade your DOS version later (see section III.A.1.).

II.D.2. I have a 1000TL/2 with Smart Drive connector on the motherboard. How can I install a drive larger than 40 Meg?

Put an AT IDE or SCSI controller in a slot and attach a drive to it. See section II.D.1.

II.D.3. Can I chain two Smart Drives together?

No. XT IDE drives cannot be chained.

II.E. Keyboards

II.E.1. My keyboard died. Where can I get a new one?

On the EX and HX, the keyboard is built in and can't be replaced. You will need to replace the system (you might be able to remove the keyboard from another EX or HX if you have one, but those systems are a pain to take apart).

The original 1000, 1000A, HD, SX, and TX have a nonstandard keyboard interface. They will need a special "Tandy-style" keyboard. These keyboards are pretty scarce. Probably the best way to get one nowadays is to look for a 1000, A, HD, SX, or TX for sale that comes with keyboard and buy the whole system.

The 1000SL, SL/2, TL, and TL/2 use an XT (or XT/AT switchable) keyboard with a standard 5-pin DIN connector. While this is a standard keyboard type, it is no longer very common. Computer Reset sells them; see section IV.G. You can also find them on eBay.

The RL's, RLX's, and (probably) the TL/3 use an XT keyboard with a PS/2 connector. You won't find one (the original keyboard was probably XT/AT autoswitching). Get an XT keyboard with standard connector (above) and use an AT-to-PS/2 adapter with it.

The RSX's use a standard PS/2 keyboard. You can get those anywhere.

Keyboards can be taken apart and cleaned; just make sure you don't lose any of the tiny parts. Let the keyboard air dry for 3 days before you put it back together and use it.

II.E.2. Can I replace my old 90-key Tandy keyboard with a 101-key keyboard?

On the EX and HX, no. On other systems, yes, at least once upon a time, but you would need a special 101-key keyboard made for the 1000's. Two such keyboards where the Northgate Omnikey and the Datadesk Turbo 1000. (SL and later systems came with a 101-key keyboard.)

II.E.3. I can get a standard XT keyboard real cheap. Can I buy/make an adapter to attach it to my old 1000?

Don't know. Tandy used to sell such an adapter (Enhanced Keyboard Adapter 25-1030), but not any more. It would not be a straightforward wiring job, since the signals are different.

II.E.4. How can I make my old keyboard more compatible?

There are a couple of TSR's that will remap your keyboard to make it more compatible; see the utilities directory on the Tvdog site. Some Tandy DOS versions come with such a utility (KEYCNVRT.SYS); also see section IV.B.1.

II.E.5. What are the scan codes for the old Tandy keyboard?

Keyboard ASCII/Scan codes

The first table in this appendix lists the keys on the Tandy 1000 keyboard
in scan code order, along with the ASCII codes they generate. For each key,
the following entries are given:

SCAN CODE - A value in the range 01H-5AH which uniquely identifies the
physical key on the keyboard that is pressed.

KEYBOARD LEGEND - The physical marking(s) on the key. If there is more than
one marking, the upper one is listed first.

ASCII CODE - The ASCII codes associated with the key. The four modes are:
  NORMAL - The normal ASCII value when only the indicated key is pressed
  SHIFT - The shifted ASCII value
  CTRL - The control ASCII value
  ALT - the alternate ASCII value
  REMARKS - Any remarks or special functions
The following special symbols appear in the table:
  x - Values preceded by an "x" are extended ASCII codes, preceded by null
  - - No ASCII code generated
  * - No ASCII code is generated but the special function described in the
      remarks column is performed.

The ALT key provides a way to generate the ASCII codes of decimal numbers in
the range 1 to 255. Hold down the ALT key while you type ON THE NUMERIC
KEYPAD any decimal number in the range of 1 to 255. When you release ALT,
the ASCII code of the number typed is generated and displayed.

NOTE: When the NUM LOCK light is off, the NORMAL and SHIFT columns for these
keys should be reversed (referring to the keypad).

All numeric values in the table are expressed in hexadecimal.

"!" means the scan code is different from the standard. Note that the ASCII
codes may still be different if not marked with "!".

QWERTY (USA) - Tandy 1000

    Scan   Kybd
    Code  Legend     normal  shift  ctrl  alt  remarks
    01    ESC          1b      1b    1b   x8b
    02    1 !          31      21   xe1   x78
    03    2 @          32      40   x03   x79
    04    3 #          33      23   xe3   x7a
    05    4 $          34      24   xe4   x7b
    06    5 %          35      25   xe5   x7c
    07    6 ^          36      5e    1e   x7d
    08    7 &          37      26   xe7   x7e
    09    8 *          38      2a   xe8   x7f
    0a    9 (          39      28   xe9   x80
    0b    0 )          30      29   xe0   x81
    0c    - _          2d      5f    1f   x82
    0d    = +          3d      2b   xf5   x83
    0e    BACK SPACE   08      08    7f   x8c
    0f    TAB          09     x0f   x8d   x8e
    10    q            71      51    11   x10
    11    w            77      57    17   x11
    12    e            65      45    05   x12
    13    r            72      52    12   x13
    14    t            74      54    14   x14
    15    y            79      59    19   x15
    16    u            75      55    15   x16
    17    i            69      49    09   x17
    18    o            6f      4f    0f   x18
    19    p            70      50    10   x19
    1a    [ {          5b      7b    1b   xeb
    1b    ] }          5d      7d    1d    -
    1c    ENTER        0d      0d    0a   x8f  MAIN KEYBOARD
    1d    CTRL          *       *     *     *  CONTROL MODE
    1e    a            61      41    01   x1e
    1f    s            73      53    13   x1f
    20    d            64      44    04   x20
    21    f            66      46    06   x21
    22    g            67      47    07   x22
    23    h            68      48    08   x23
    24    j            6a      4a    0a   x24
    25    k            6b      4b    0b   x25
    26    l            6c      4c    0c   x26
    27    ; :          3b      3a   xf6   xf8
    28    ' "          27      22   xf7   xf1
!   29    UP ARROW    x48     x85   x90   x91
    2a    SHIFT         *       *     *     *  LEFT SHIFT
!   2b    LEFT ARROW  x4b     x87   x73   x92
    2c    z            7a      5a    1a   x2c
    2d    x            78      58    18   x2d
    2e    c            63      43    03   x2e
    2f    v            76      56    16   x2f
    30    b            62      42    02   x30
    31    n            6e      4e    0e   x31
    32    m            6d      4d    0d   x32
    33    , <          2c      3c   xf9   x89
    34    . >          2e      3e   xfa   x8a
    35    / ?          2f      3f   xfb   xf2
    36    SHIFT         *       *     *     *  RIGHT SHIFT
!   37    PRINT        10       *    72   x46  SCR PRINT TOGGLE
    38    ALT           *       *     *     *  ALTERNATE MODE
    39    SPACE BAR    20      20    20    20
    3a    CAPS LOCK     *       *     *     *  CAPS LOCK
    3b    F1           x3b    x54   x5e   x68
    3c    F2           x3c    x55   x5f   x69
    3d    F3           x3d    x56   x60   x6a
    3e    F4           x3e    x57   x61   x6b
    3f    F5           x3f    x58   x62   x6c
    40    F6           x40    x59   x63   x6d
    41    F7           x41    x5a   x64   x6e
    42    F8           x42    x5b   x65   x6f
    43    F9           x43    x5c   x66   x70
    44    F10          x44    x5d   x67   x71
    45    NUM LOCK       *      *     *     *  NUMBER LOCK
!   46    HOLD           *      *     *     *  FREEZE DISPLAY
    47    7 \           37     5c   x93     *
    48    8 ~           38     7e   x94     *
    49    9 PG UP       39    x49   x84     *
!   4a    DOWN ARROW   x50    x86   x96   x97
    4b    4 |           34     7c   x95     *
    4c    5             35    xf3   xfc     *
    4d    6             36    xf4   xfd     *
!   4e    RIGHT ARROW  x4d    x88   x74   xea
    4f    1 END         31    x4f   x75     *
    50    2 `           32     60   x9a     *
    51    3 PG DN       33    x51   x76     *
    52    0             30    x9b   x9c     *
!   53    - DELETE      2d    x53   x9d   x9e
!   54    BREAK        x00    x00     *     *  CTRL BREAK is the ctrl brk
                                                 routine
                                               ALT BREAK is the scroll lock
!   55    + INSERT      2b    x52   x9f   xa0
!   56    .             2e    xa1   xa4   xa5  NUMERIC KEYPAD
!   57    ENTER         0d     0d    0a   x8f  NUMERIC KEYPAD
!   58    HOME         x47    x4a   x77   xa6
!   59    F11          x98    xa2   xac   xb6
!   5a    F12          x99    xa3   xad   xb7

Keyboard layout:

    F1  F2  F3  F4      F5  F6  F7  F8      F9 F10 F11     F12            +       -    break
   esc  1   2   3   4   5   6   7   8   9   0   -   =   backspace  alt  print   7   8   9
    tab   q   w   e   r   t   y   u   i   o   p   [   ]           hold  numlk   4   5   6
   control  a   s   d   f   g   h   j   k   l   ;   '    enter     up   home    1   2   3
 caps  shift  z   x   c   v   b   n   m   ,   .   /  shift  left  down  right   0   .  enter
                         space

II.F. Processors, Coprocessors and Motherboards

II.F.1. How can I increase the speed of the main processor?

You can replace the 8088 in the original 1000, A, HD, EX, or HX with an NEC V-20, and you can replace the 8086 in the SX or SL's with an NEC V-30. Both chips are extremely cheap and will provide about a 30% speedup. The V-20 will work in about 70% of original 1000's and 1000A's; in the other 30%, the machine will either fail to boot or behave erratically with the V-20 installed. There is no way of knowing in advance which machines the V-20 will work with. The 8086 in the RL's is surface mounted and can't be replaced. Jameco sells V-20's (see section IV.G.). A quick Web search as I am writing this turns up a guy in Europe selling V-30's. A side advantage of the V-20 and V-30 is that they can execute some 80286 instructions, if you need to run software that requires a 286.

The 1000 and 1000A can take a daughterboard called the "PC Sprint" that doubles the clock speed. The upgrade comes with both V-20 and 8088-2 processors, since as noted above it may be necessary on some systems to stay with an Intel chip. The speedup from the PC Sprint is up to 100%, depending on the application and whether the NEC chip can be used. DCS Industries used to sell the PC Sprint. There is a file describing how to wire up the board yourself, but it doesn't look like something you should try unless you're an engineer ;-).

There was a "286 Express" card made by PC Technologies for the 1000, 1000A, and 1000SX and sold by Tandy. Those cards were incompatible with some programs and expansion cards, and the SX tends to lock up a lot with one. Other 286 or 386 in-circuit emulator cards will not work. Results with the 286 Express card are reportedly better when using the card's TSR driver in AUTOEXEC.BAT rather than the CONFIG.SYS driver. It may be necessary to disable 286 mode on the card to load some TSR's, such as a mouse driver, and to run some programs.

For 286's, Evergreen made 386 and 486 daughterboards that you can replace the 286 with. The daughterboards will fit in the TL, TL/2, and TX, but not in the TL/3, RLX, or RLX-HD. Improve Technologies made similar daughterboards (theirs were called "Make it 386" and "Make it 486"). Nowadays, these daughterboards are scarcer than hen's teeth.

The Cyrix 486SRx2 was a clip-on upgrade for 386SX's that should work in the 1000RSX - if you can find it, which is not very likely.

There are programs to speed up the system by reducing the RAM refresh rate. You can get 10-20% speedup with them, but be careful: setting the refresh rate too low makes the memory unstable - and since the memory in the 1000-series (except the RSX) is not parity checked, the only sign that the rate is too low is inexplicable system crashes.

II.F.2. Can I install a math coprocessor?

On the EX, HX, RL's, and RLX's, no (there's no socket). On the original 1000, you have to add a socket before you can add a chip (see below). Otherwise, yes. You can find 8087, 80287, and 80387 chips for sale on eBay from time to time; people collect them nowadays. Make sure you are getting a working chip, though - collectors don't care, but you do.

To install a math coprocessor in the original 1000, you had to remove the 8088 and plug a daughterboard in in its place. The 8088 and 8087 were plugged into the daughterboard. The daughterboard was manufactured by Trionix, 3563 Roosevelt #B, Carlsbad, CA 92008 and sold by Tandy. You probably won't find one.

II.F.3. Can I replace the motherboard?

Blasphemy! :-) Seriously, this is a definite "maybe." You need to make sure (a) that the board is small enough to fit in the case, and (b) that the slots in back line up with the openings in the case. You are likely to have trouble with (b). DCS Industries used to sell 486 and Pentium replacement motherboards for the SL's, TL's, RL's, RLX's, and RSX's. You are unlikely to be able to fit a replacement motherboard in the EX or HX. Frankly, at current prices it makes more sense just to get a whole new system.

Replacement motherboards for the 1000's were reviewed in the December 1992 issue of PCM (see section IV.C.).

II.F.4. I want to slow my computer down so an old game will run. Where is the turbo switch?

Some of the 1000-series have two speeds, usually normal speed and half-speed, but there is no hardware turbo switch. Instead, additional parameters to the DOS Mode command are used: MODE SLOW (for half speed) and MODE FAST (for normal speed). This is a special feature of Tandy DOS and will disappear if you upgrade the DOS version (see section III.A.2.).

If you've already upgraded (so it's too late), you can try this program:

ftp://ftp.oldskool.org/pub/tvdog/tandy1000/utilities/speed.zip

It was written for the 1000SX, but it works on the 1000TL and might work on other 1000's as well.

On older 1000's, the speed may be toggled by pressing a key at boot time. Ryan Davies writes:

At least on the Tandy 1000 TX, you can slow down the system by pressing F4 (I think that's the key) at startup to slow it down for the whole session. This is necessary for DOS upgraders (I did to 6.2 -- big mistake, I think). It changes mine from 8Mhz to 4Mhz.... [I]t says right above the four function keys what they do at startup. Just remove the writeable tab covering them.

There are also TSR's around to slow down a PC that you can use; check any large FTP archive.

II.G. Serial Ports, Modems, and Mice

II.G.1. Can I use a fast modem with my 1000?

Upgrading Your Tandy (see section IV.D.) reports that the original 1000 may have trouble with an internal modem. You can install a serial port and use an external modem. T.J. Harrell confirms the problem, and the workaround.

If it's a Winmodem, no. Winmodems are brain-dead crap that only work under Windows (and not Windows 3.x). Rockwell RPI modems are also brain-dead crap, almost but not completely useless, and generally to be avoided.

Otherwise, if it's an internal modem, generally yes (make sure it is an ISA card, not PCI). A problem can arise with external modems in that the serial port on (most?) of the 1000's has an 8250A UART, which is not suitable for high-speed data transfers; you will need to install another serial port with a 16550 UART chip (see section II.G.4.).

On early models with 8088 or 8086 processors, you might not be able to use a 28.8k modem at its full rate. Marc Williams writes the following:

One BBS I call I set PCPLUS up at 115K and the board works fine. Checked with the W2 command and the connect is either 26.4K or 28.8K.

When I got this present batch of mail the connect was 28.8K but the modem did what I expected. On only two boards in the past my modem had the habit of its CD light blinking like crazy. Sometimes for only a few seconds, sometimes so long the board will disconnect for inactivity. At present when it does happen with the ISP (like today) I'll be disconnected immediately.

Anyhind, back to the rate. Depending on the board I'm calling I usually get 21.6K or 24K (IIRC) and with the internet stuff it's 26.4K with no problems.

He has a 1000HX with a 16550 UART and an external 28.8k modem.

14.4k modems should work fine in any system.

II.G.2. Windows doesn't recognize the mouse on my RLX. What's wrong?

The mouse driver that comes with Windows expects the PS/2-type mouse on the RLX to use IRQ 12. The RLX doesn't have IRQ's above 7. The solution is to use a serial (Microsoft) mouse.

To use the PS/2 mouse port on the RLX (with DOS or DeskMate), you also have to enable it with Setuprlx.

II.G.3. My system doesn't have a serial port. Can I add one?

II.G.4. Can I add another serial port?

The original 1000, 1000A, HD, EX, HX, and SX did not come with a serial port. Of these, the original 1000, 1000A, HD, and SX can take a standard 8-bit serial port card. The EX and HX need a special card because of their nonstandard slots.

You can add a second serial port to any system, but the BIOS may not recognize more than two. Again, the EX and HX need special cards. Having the BIOS not recognize the port may not really be a problem, depending on the software for the serial device involved (i.e., communication programs usually program the port directly rather than through the BIOS). There are also programs available to "manually" patch the BIOS serial port list in low memory if need be, and you could easily make one with Debug. On my 1000TL, I found that a third serial port on COM4: would work, but COM3: would not; the BIOS does not recognize the third port, but that's OK.

Be careful with multi-function cards that come with game ports and hard drive or floppy drive controllers. If your system has built-in joystick ports, you will have to use them instead of the ones on the card, since they can't be disabled. Likewise, if the card comes with a hard drive controller, you will have to disable it. None of the 1000's can use the "el cheapo" AT IDE controllers that come on an I/O card. The floppy drive controller on the card will also have to go. You can add a secondary floppy controller, but you will need one with a built-in BIOS (see also section II.C.1.).

II.G.5. What kind of mouse is this, and where do I get a driver for it?

Tandy sold at least 5 different types of mice for the 1000-series. First, there was the standard Microsoft (serial) mouse. Second, the RSX's came with a port for a standard PS/2 mouse. You can use the standard MOUSE.COM or MOUSE.SYS for those two. Third, the TL/3, RL's, and RLX's have a connector for a PS/2 mouse, but it needs a special mouse driver because it uses a nonstandard interrupt. CuteMouse v1.9 works. Fourth, the DigiMouse is a bus mouse using a special controller card, which was available both as a standard 8-bit card (cat. no. 26-5144 or 25-1010) and as a PLUS card (25-1015). There is a driver for it here.

The Color Mouse is a joystick made up to look like a mouse (it plugs into a 6-pin joystick port). It is so called because it was the mouse used on the Color Computer (see section IV.H.). DeskMate directly supports the Color Mouse without an external driver; select "joystick" as the mouse type in Setup. Otherwise, the DOS driver for this mouse was called JOY.SYS. The Tandy support site talks mainly about using the Color Mouse as a joystick replacement in games, however.

The mouse port on the TL/3, RL's and RLX's may also need to be enabled using the system setup program - see section III.E.1. If the mouse is enabled but not working, try disabling it, rebooting, then reenabling and rebooting again; that sometimes "wakes it up." DeskMate that came with those systems has a built-in driver for the mouse, so you can use DeskMate to check whether the mouse works independently of whether you have the right DOS driver.

II.H. Parallel Ports and Printers

II.H.1. My printer keeps double-spacing. How do I make it stop?

According to Tony Gordon:

Well, on some Tandy printers, specifically the DMP models that I have used (DMP 130, 130A) there are a bank of dip switches that control various functions of the printer. One of them controls the LF/CR signals. You can set it to LF=LF or LF=LF/CR (double spacing) LF=LF just interprets the line feed. It will interpret the carriage return when it is sent. LF=LF/CR means that when a LF is sent, the carriage is also returned to home position, and since most lines come to the computer with a CR/LF, you get double spacing.

Some people are hesitant about modifying dip switches and such, so you can run LPINST and it will ask you a couple of questions about your printer (whether it double spaces when you want single spacing or if it prints on the same line without advancing the paper). It then creates/updates an AUTOEXEC.BAT file with the correct DOS commands, (i.e. LF and MODE) for your printer so that it will space properly.

Using the wrong printer cable may cause this problem - see section II.H.4.

II.H.2. What kinds of printers can I use with a 1000?

Most types of printers can be used with a Tandy 1000 provided you use an appropriate printer cable to connect to your computer. Be careful of laser printers that expect a bidirectional parallel port, however (see section II.H.5.). The printer port on the TL/3, RLX's, and RSX's is a standard 25-pin port. The system setup program controls whether it is bidirectional or not. The RL and RL-HD also have a standard 25-pin port; it is unidirectional.

A veteran programmer with Tandy writes:

WARNING: Some newer printers can be blown out (or blow the computer out) by connecting them to a TRS-80 model I, II, III, 4, 4P, 12, 16, or 100; or a Tandy 6000, 1000, 1200, or 2000. These systems used a Centronics-standard printer interface and newer printers usually have a IBM-PC printer interface. Trust IBM to not follow an existing industry-standard and to use the same connector and 95% of the same signals. Don't get burned.

The following information was provided by:

William K. Walker
North Valley Digital
P.O. Box 1941
Kalispell MT 59903-1941
+1 (406) 257-2306
71066.24@compuserve.com

     PRINTER CABLE SELECTION GRID (PARTIAL)
     --------------------------------------
                COMPUTER TYPE     "OLD": Any Tandy 1000 series except 1000RL's,
PRINTER         "OLD"   "NEW"            RLX's, RSX, and TL/3. (These systems
-------         -----   -----            have a card-edge printer port.)
CGP 115           A       C       "NEW": All other IBM compatibles, including
CGP 220           A       C              laptops. (These systems have a
DMP 100           A       C              normal 25-pin printer port.)
DMP 105           A       C       Tandy cable catalog numbers:
DMP 106           A       C                 6 foot   12 foot
DMP 107           A       C            A   26-0225   26-0222
DMP 110           A       C            B   26-0289   26-1259
DMP 120           A       C            C   26-0227   26-0223
DMP 130           A       C            D   26-0288   26-1258
DMP 130A          A       C            E   26-1416
DMP 132           A       C
DMP 133           A       C
DMP 134           B       D
DMP 135           B       D
DMP 136           B       D
DMP 137           B       D
DMP 200           A       C
DMP 202           B       D
DMP 203           B       D
DMP 204           B       D
DMP 205           B       D
DMP 206           B       D
DMP 207           B       D
DMP 2100          A       C
DMP 2100P         A       C
DMP 2102          A       C
DMP 2103          B       D
DMP 2104          B       D
DMP 2110          A       C
DMP 2120          A       C
DMP 2130          B       D
DMP 2200          A       C
DMP 240           B       D
DMP 250           B       D
DMP 300           A       C
DMP 302           B       D
DMP 310           B       D
DMP 400           A       C
DMP 420           A       C
DMP 430           A       C
DMP 440           A       C
DMP 442           A       C
DMP 500           A       C
DWP I (Qume)      A       C
DWP II            A       C
DWP 210           A       C
DWP 220           A       C
DWP 230           A       C
DWP 410           A       C
DWP 510           A       C
DWP 520           A       C
FP 215            A       C
JP 250            B       D
Line Printer I    A       C
Line Printer II   E
Line Printer III  A       C
Line Printer IV   E
Line Printer V    A       C
Line Printer VI   A       C
Line Printer VII  A       C
Line Printer VIII A       C
LMP 2150          A       C
LP 400            B       D
LP 410            B       D
LP 800            B       D
LP 950            B       D
LP 990            B       D
LP 1000           A       C
Plotter Printer   A       C
Quick Printer II  E
Screen Printer    E
TRP 100           A       C
IBM type printers B       D
EPSON type        B       D
Panasonic type    B       D
(I've added some to the above.) Printers that use cable types "B" or "D" have a standard port. Printers that use cable types "A" or "C" have a port that looks like a standard one but isn't. Printers that use cable type "E" have a card edge connector.

Cable type "D" is the standard cable that you can get from your local computer store. If you need one of the other cable types, you need to get (or make) the special Tandy cable. If your Tandy printer is not listed, contact Radio Shack customer support to find out which cable you need (see section IV.A.). If your non-Tandy printer is not listed, use cable "B" or "D", depending on what type of computer you have.

It is possible to make your own printer cable. There was a good article on the subject by David P. Miller, "Talking to Your Printer," in Computer News PC, vol. 3, no. 12, pp. 12-14.

Here are the pin connections for cable type "A" (26-0225/0222):

    _____________________________________________________
   |                                                     |
   |  1  3  5  7  9 11 13 15 17 19 21 23 25 27 29 31 33  |
   |                                                     |
   |  2  4  6  8 10 12 14 16 18 20 22 24 26 28 30 32 34  |
   |_____________________________________________________|
        female card edge printer connector (pin side)
 ___________________________________________________________
|                                                           |
|    1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18   |
\                                                           /
 \  19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36  /
  \_______________________________________________________/
         male Centronics printer connector (pin side)

            Card edge pin       Centronics pin(s)
            -------------       -----------------
                  1                     1        
                  2                    19
                  3                     2
                  4                    20
                  5                     3
                  6                    21
                  7                     4
                  8                    22
                  9                     5
                 10                    23
                 11                     6
                 12                    24
                 13                     7
                 14                    25
                 15                     8
                 16                    26
                 17                     9
                 18                    27
                 19                    10
                 20                    28
                 21                    11
                 22                    29
                 23                    12
                 24                    30
                 25                    13
                 26                    31
                 27                    14
                 28                    32
                 29                    15
                 30                    33
                 31                    16
                 32                    34
                 33                    17
                 34                    35
                 n/c                 18, 36

And here are the pin connections for cable type "B" (26-0289/1259):

    _____________________________________________________
   |                                                     |
   |  1  3  5  7  9 11 13 15 17 19 21 23 25 27 29 31 33  |
   |                                                     |
   |  2  4  6  8 10 12 14 16 18 20 22 24 26 28 30 32 34  |
   |_____________________________________________________|
        female card edge printer connector (pin side)
 ___________________________________________________________
|                                                           |
|    1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18   |
\                                                           /
 \  19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36  /
  \_______________________________________________________/
         male Centronics printer connector (pin side)

            Card edge pin       Centronics pin(s)
            -------------       -----------------
                  1                     1        
                  2                    19
                  3                     2
                  4                    20
                  5                     3
                  6                    21
                  7                     4
                  8                    22
                  9                     5
                 10                    23
                 11                     6
                 12                    24
                 13                     7
                 14                    25
                 15                     8
                 16                    26
                 17                     9
                 18                    27
                 19                    10
                 20                    28
                 21                    11
                 22                    29
                 23                    12
                 24                    30
                 25                    13
                 26                    n/c
                 27                    14
                 28                    32
                 29                    n/c
                 30                    31
                 31                    16
                 32                    34
                 33                    17
                 34                    35
                 n/c                 18, 36

And here are pin connections for cable type "C" (26-0227/0223):

         __________________________________________
        |                                          |
        |   1  2  3  4  5  6  7  8  9 10 11 12 13  |  
        \                                          /
         \   14 15 16 17 18 19 20 21 22 23 24 25  /
          \______________________________________/
              male DB-25 connector (pin side)
 ___________________________________________________________
|                                                           |
|    1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18   |
\                                                           /
 \  19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36  /
  \_______________________________________________________/
         male Centronics printer connector (pin side)
                
              DB-25 pin       Centronics pin(s)
              ---------       -----------------
                  1                   1        
                  2                   2
                  3                   3
                  4                   4
                  5                   5
                  6                   6
                  7                   7
                  8                   8
                  9                   9
                 10                  10
                 11                  11
                 12                  12
                 13                  18
                 14                  n/c
                 15                  32
                 16                  33
                 17                  n/c
                 18                  23
                 19                  24
                 20                  25
                 21                  26
                 22                  27
                 23                  28
                 24                  29
                 25                  30
                 n/c          13-17, 19-22, 31,
                                    34-36

You might find one on eBay from time to time, but most likely if the cable you need didn't come with your printer, you will need to make it, using the pinouts above.

You can install a standard parallel port in an expansion slot, if you have a system with a card-edge printer port. You will need to jumper the card for LPT2: to avoid conflicting with the built-in port.

The serial ports on older Tandy printers are for connecting to the Color Computer. They are not compatible with an IBM PC serial port.

II.H.3. What is the pinout for the card-edge printer connector?

Tandy once made cables to connect various printers to the card-edge port. See section II.H.2.
    __33_31_29_27_25_23_21_19_17_15_13_11__9__7__5__3__1__
   |______________________________________________________|
      34 32 30 28 26 24 22 20 18 16 14 12 10  8  6  4  2
        male card edge printer connector (finger side)

Pin      Designation          Direction      Notes
---      -----------          ---------      -----
  1      *Strobe                 out
  2      Ground                  out
  3      Data 0                  out
  4      Ground                  out
  5      Data 1                  out
  6      Ground                  out
  7      Data 2                  out
  8      Ground                  out
  9      Data 3                  out
 10      Ground                  out
 11      Data 4                  out
 12      Ground                  out
 13      Data 5                  out
 14      (not connected)         n/a
 15      Data 6                  out
 16      Ground                  out
 17      Data 7                  out
 18      Ground                  out
 19      *Acknowledge            in
 20      Ground                  out
 21      Busy                    in
 22      Ground                  out
 23      Paper End               in
 24      Ground                  out
 25      Select                  in          Jumper controlled.
 26      (not connected)         n/a
 27      *Auto Feed              out         Original 1000, A, HD: Ground. 
 28      *Error                  in
 29      (not connected)         n/a
 30      *Initialize Printer     out
 31      Ground                  out
 32      (not connected)         n/a         Original 1000, A, HD: Auto Feed.
 33      Ground                  out
 34      +5V                     out         Original 1000, A, HD: not connected.
* = active low
As noted, the card edge printer port in the original 1000, A, and HD is slightly different from later models. On several models, the Select signal is by default wired high rather than connected to the printer; a jumper must be installed to connect it (see section II.H.5.). All the ground pins shown above are wired together on the motherboard.

II.H.4. Can I connect my old Tandy printer to my new computer?

The short answer is "yes," as long as you use the right cable; see section II.H.2. If you want the gruesome details, read the following.

Tandy confirmed (in a user newsletter) that permanent damage to the computer can result when attaching old Tandy printers (DMP 133, 440 and 107, the LP 1000, and older models) to newer clones, particularly the Packard Bell. The problem results from +5V being supplied by the printer on Centronics pin 18, which is not standard for IBM.

There is a problem with double-spacing on old Tandy printers when connected to newer machines. This problem is solved by covering pin 14 on the printer cable at the computer end with Scotch tape (or by using a Tandy cable). The problem can also be handled by a MODE LFOFF command at the DOS prompt, but this will not work with all programs, particularly those with their own printer drivers.

Old DMP's use Centronics pin 33 as the INIT line, while the IBM standard is to tie that pin to ground. This places the DMP's in a permanent INIT state, so they do not work.

Some old Tandy printers do not support the IBM/Epson control code set. Reportedly, they can be upgraded to do so by replacing the printer's ROM chip (the only such ROM upgrade that I know of is for the DMP 2110).

Wayne Day writes:

A.D. You obviously saw the PC-to-Tandy cable comparison. Here it is, again, so you can put it into the FAQ. Note, one of my members on CompuServe did the work, and I don't know who it is, so please don't credit me with this. [Sorry, Wayne ...]
.    IBM Cable                  Tandy Cable
. 25pin      36 pin          25pin      36 pin
.   1 --------- 1              1 --------- 1
.   2 --------- 2              2 --------- 2
.   3 --------- 3              3 --------- 3
.   4 --------- 4              4 --------- 4
.   5 --------- 5              5 --------- 5
.   6 --------- 6              6 --------- 6
.   7 --------- 7              7 --------- 7
.   8 --------- 8              8 --------- 8
.   9 --------- 9              9 --------- 9
.  10 -------- 10             10 -------- 10
.  11 -------- 11             11 -------- 11
.  12 -------- 12             12 -------- 12
.  13 -------- 13             13 -------- 18
.  14 -------- 14             14 --
.  15 -------- 32             15 -------- 32
.  16 -------- 31             16 -------- 33
.  17 -------- 36             17 --
.  18 ----*--- 16             18 -------- 23
.  19 ----|--- 19             19 -------- 24
.  20 ----|--- 20             20 -------- 25
.  21 ----|--- 21             21 -------- 26
.  22 ----|--- 22             22 -------- 27
.  23 ----|--- 23             23 -------- 28
.  24 ----|--- 24             24 -------- 29
.  25 ----|--- 25             25 -------- 30
.         |--- 26                      -- 13
.         |--- 27                      -- 14
.         |--- 28                      -- 15
.         |--- 29                      -- 16
.         |--- 30                      -- 17
.         *--- 33                      -- 19
.           -- 15                      -- 20
.           -- 17                      -- 21
.           -- 18                      -- 22
.           -- 34                      -- 31
.           -- 35                      -- 34
.                                      -- 35
.                                      -- 36
Look at pins 13, 14, and 16, from the 25 pin side, and you'll find the culprits. These three signals go to different places in the 36 pin connector. All of the signals that are tied together in the IBM cable are grounds, and the grounds in the Tandy cable are separate, so that grounding takes place after the cable is hooked up. But pin 33 in the Tandy printers is the initialize printer signal, and with the IBM cable, it's hooked to ground, and knocks the printer off line.

Chances are that swapping pins 31 and 33 (at the printer end of the cable), plus disconnecting pin 14 will probably do the job. If necessary, also swap pins 13 & 18.

Instead of modifying an existing cable, you could make your own from scratch (see section II.H.2.).

II.H.5. Can I use a parallel-port peripheral (other than a printer with my card-edge printer port?

Probably not. It will only work if the device is unidirectional (output only). You will need an adapter to convert the card-edge parallel port to a standard one (a company called PC Enterprises used to sell them). John B. Sandlin gave instructions for making a parallel port adapter on his Web site. Here are the connectors for the two port types:
         __________________________________________
        |                                          |
        |  13 12 11 10  9  8  7  6  5  4  3  2  1  |
        \                                          /
         \   25 24 23 22 21 20 19 18 17 16 15 14  /
          \______________________________________/

             Pin Orientation of DB-25 Connecter
           looking at the side away from the cable

    _____________________________________________________
   |                                                     |
   |  1  3  5  7  9 11 13 15 17 19 21 23 25 27 29 31 33  |
   |                                                     |
   |  2  4  6  8 10 12 14 16 18 20 22 24 26 28 30 32 34  |
   |_____________________________________________________|

         Pin Orientation of 34 pin Card Edge Socket
           looking at the side away from the cable
This is how you wire it:
     DB-25      34 pin socket
     -----      -------------
       1               1      
       2               3
       3               5
       4               7
       5               9
       6              11
       7              13
       8              15
       9              17
      10              19
      11              21
      12              23
      13              25
      14              27
      15              28
      16              30
      17              N/C
      18        2, 4, 6, 8, 10
      19              12
      20              14
      21              16
      22              18
      23              20
      24              22
      25          24, 31, 33
      N/C       26, 29, 32, 34

See John's Web site for detailed instructions on making the adapter.

Be aware that some devices cannot be used with a unidirectional port and will damage your machine if you try. Ryan Davies writes:

Please make mention to users wanting to attach other peripherals (especially laser printers) to the existing card-edge printer port on all Tandys with that kind of port that it is 4-bit (not bi-directional) and any bi-directional attempt on this port can possibly even damage the motherboard and fry the peripheral's system board. (not like I'm speaking from experience or anything....)

He adds that "my Tandy's parallel port is dead." He has a 1000TX.

It is preferable to get a bidirectional parallel port on an expansion card and use that, if you have a slot available. Be sure to jumper the card for the secondary address to avoid conflict with the built-in port. Otherwise, on some models you can disable the built-in parallel port using the /A option on the system setup program.

II.I. Expansion Slots

II.I.1. How can I get standard expansion slots on a 1000HX or EX?

DCS Industries used to sell a slot box you could use to add standard slots. The slot box comes with four additional drive bays and a 200-watt power supply.

Otherwise, you can make an adapter. As with any project where you're modifying your computer's electronics, do this at your own risk.

The "PLUS"-style expansion slots in the 1000EX and 1000HX are not quite electrically the same as an 8-bit IBM-standard expansion slot (see section II.I.4.). One major difference is the lack of DMA in the EX and HX as they came from the factory. A DMA chip is included on the expansion cards that increase memory above 256k.

Unfortunately, expansion cards that use the "PLUS" connector tend to be a lot more expensive than the same cards that use the standard card-edge connector - and there are a lot fewer of them available.

I got this third hand; a gentleman named Jay Wigginton originally posted this on some online service, perhaps America Online, in 1989. You need the following parts:

(1) Radio Shack Plus Adapter Board, catalog number 25-1016. It was $14.95 in 1989. This was a standard 8-bit card to which one of the special "PLUS" cards made for the 1000EX and HX could be attached - essentially the reverse of the adapter you're making.

(2) Female "PLUS" header connector, part number 8519257. This is a part off of the 1000EX/HX "PLUS" memory expansion card referred to above. Get it from Tandy National Parts (see section IV.G.). (You still need to have the memory card itself if you want to get DMA, as noted above.)

(3) 31/62 pin edge connector, part number 8519236. This is a part off of the 1000SX. It comes from Tandy National Parts also. It is the female (motherboard) side of a standard 8-bit slot connector.

According to Mr. Wigginton, you first remove the male PLUS connector (by desoldering) from (1), "being careful not to damage the board." Next, cut the top off of (1) down to just above where the "PLUS" connector was. Cut the "edge finger" (male edge connector) off of the bottom of (1), "leaving about 1/8 inch of the gold fingers exposed below the solder mask (the green covering on the board)" (Wigginton notes that that cut is optional - the cutting is probably best done with a grinding wheel).

Now solder the female edge connector (3) to the holes left when you removed the "PLUS" connector from (1). "It will be necessary to bend the pins so that they fit," Wigginton notes. The connector should be attached on the side of (1) with printing.

Finally, solder (2) to the edge fingers on (1). "Check all pins for shorts to other pins. Use a continuity checker. This is very important; it will not function if any pins are shorted together."

OR ... you could do it the easy way. Just get some 62-pin ribbon cable and crimp-on connectors, 62-pin female to connect to the Plus memory card and 62-pin card edge to plug standard cards into. Crimp them together and you have your adapter. As above, check for continuity on all pins and shorts on adjacent pins. Keep the length of the cable to 9" or less.

II.I.2. How can I add additional expansion slots?

At one time you could buy a slot box. If you're handy, you may be able to modify an old XT to work as a slot box; otherwise, ISA expansion chassis can still be purchased, but they are very pricey - over $1000 each.

There were also "add card" riser cards made. These were standard 8- or 16-bit cards with 3-4 additional slots on the side of the card. There are companies that still make them. Check out this site, for example:

http://www.adexelec.com/isa.htm

II.I.3. What kinds of cards will work in the slots on a 1000?

The EX and HX will require special cards made for them, unless you make an adapter (see section II.I.1.). Other systems can use most standard 8-bit cards. The cards will need to be 10" in length or shorter to fit in the case ("1/2 length" or "3/4 length"). The types of cards to watch out for here are hard cards and EMS cards - it's mostly very old cards that are too long (the original 8-bit IBM VGA card is too long, as is the original Xebec hard drive controller). Only the RSX's can take 16-bit cards - though some 16-bit cards will work in an 8-bit slot (some ISA VGA controllers, for example).

The slots on the original 1000, A, HD, SX, and TX are physically the same as a standard 8-bit slot, but differ in some signals. On the original 1000 and 1000A, there is no DMA unless a memory expansion card is installed. Models up to the TX also use IRQ 5 for vertical sync and will require a hard drive controller that uses IRQ 2 (on the SX and TX you can flip a switch on the motherboard to disable IRQ 5 on the motherboard and use a standard controller, but not on the original 1000 or 1000A). See section II.D.1. regarding hard drives.

Space inside some models is particularly tight, the RL and RLX for example. It would be a good idea before you buy a card to open up the case and see the lay of the land, maybe even take a picture.

II.I.4. What is the pinout for the Plus expansion connector in the 1000HX and EX?

           (Back of machine)
   A1    NMI             B1   Ground
   A2    D7              B2   BRESET
   A3    D6              B3   +5 Volts
   A4    D5              B4   IRQ2
   A5    D4              B5   N/C
   A6    D3              B6   FDCMRQ
   A7    D2              B7   -12 Volts
   A8    D1              B8   N/C
   A9    D0              B9   +12 Volts
   A10   RDYIN           B10  Ground
   A11   AEN             B11  MEMW*
   A12   A19             B12  MEMR*
   A13   A18             B13  IOW*
   A14   A17             B14  IOR*
   A15   A16             B15  N/C     
   A16   A15             B16  N/C
   A17   A14             B17  N/C
   A18   A13             B18  N/C
   A19   A12             B19  REFRESH*
   A20   A11             B20  CLK
   A21   A10             B21  RFSH*
   A22   A09             B22  BREQ*
   A23   A08             B23  N/C
   A24   A07             B24  IRQ4
   A25   A06             B25  IRQ3
   A26   A05             B26  FDCDACK*
   A27   A04             B27  DMATC
   A28   A03             B28  ALE
   A29   A02             B29  +5 Volts
   A30   A01             B30  OSC
   A31   A00             B31  Ground
For reference, here is the pinout for a standard 8-bit slot:
           (Back of machine)
   B01   Ground          A01  IOCHCHK*
   B02   RESET           A02  D7
   B03   +5 Volts        A03  D6
   B04   IRQ2            A04  D5
   B05   -5 Volts        A05  D4
   B06   DRQ2            A06  D3
   B07   -12 Volts       A07  D2
   B08   NOWS*           A08  D1
   B09   +12 Volts       A09  D0
   B10   Ground          A10  IOCHRDY
   B11   MEMW*           A11  AEN
   B12   MEMR*           A12  A19
   B13   IOW*            A13  A18
   B14   IOR*            A14  A17
   B15   DACK3*          A15  A16
   B16   DRQ3            A16  A15
   B17   DACK1*          A17  A14
   B18   DRQ1            A18  A13
   B19   REFRESH*        A19  A12
   B20   CLK             A20  A11
   B21   IRQ7            A21  A10
   B22   IRQ6            A22  A09
   B23   IRQ5            A23  A08
   B24   IRQ4            A24  A07
   B25   IRQ3            A25  A06
   B26   DACK2*          A26  A05
   B27   DMATC           A27  A04
   B28   ALE             A28  A03
   B29   +5 Volts        A29  A02
   B30   OSC             A30  A01
   B31   Ground          A31  A00
Side "A" is the component side on a standard XT card. Note that the Plus card slot is electrically identical to a standard XT slot on the "A" side, but there are several differences on the "B" side. DMA signals on B15-18 are added by the memory expansion card if installed. Pins B06, B21, B22, B26, and B27 are actually the same but with different names. -5 volts is often not implemented on a standard slot.

Most cards will work if you make an adapter (see above), especially if you have a memory card installed. Some expansion cards used in the 1000-series have the same connector.

II.J. Game Ports, Joysticks, and Sound

II.J.1. Can I use a standard joystick?

On the RSX and RSX-HD, yes. You need to get an expansion card with game ports on it. Otherwise, no, since you have built-in game ports that cannot be disabled. The following systems have two 6-pin DIN (round) joystick ports: original 1000, 1000A, HD, EX, HX, SX, TX, SL's, TL's, RL's, and RLX's ("A" versions). To install a joystick on those systems, you need to use a Tandy-style joystick; they turn up on eBay from time to time (the Color Computer uses the same joysticks). The RLX-B and RLX-HD-B have two 8-pin mini-DIN joystick ports. There was an adapter available from Tandy for connecting a 6-pin joystick to the RLX's ports, part 26-0284.

The Tandy 1000 game ports are not 100% compatible with standard ports, but they work most of the time, with most software.

If you have built-in game ports and try to use a standard joystick with an expansion card, the new joystick will only work with some software, or only when a joystick is connected to the built-in port, or only when it isn't - or only when the moon is full on a Friday. (It seems to work on my 1000TL, though - not that I've given it much tryout.)

It is possible to make an adapter to attach a standard joystick to the 6-pin port (see section II.J.4.).

II.J.2. Can I emulate SoundBlaster with the Tandy DAC?

No. There are some programs for the Tandy DAC at the tvdog site (see section IV.B.1.).

If you want SoundBlaster compatibility, you can install a SoundBlaster or SoundBlaster Pro in an expansion slot. If you do so, you will have to stop using the Tandy DAC, since the SoundBlaster drivers will be confused by the DAC BIOS routines.

It is possible to emulate the Covox Speech Thing (dumb DAC) with the Tandy DAC, if your program supports that. Get file:

ftp://ftp.oldskool.org/pub/tvdog/tandy1000/sound/tspak181.zip

II.J.3. Can I install a Tandy DAC or 3-voice chip in a normal PC?

Probably not. Tandy once made a PSSJ expansion card ("PSSJ" is the name of the sound chip), but they are very rare. If you find the card, you will need to jumper it for IRQ 7, DMA 1, as software for the Tandy DAC expects those settings. The "SayIt" card from Roar Technology of Canada may be the same (see section III.B.7.).

There are emulators for the 3-voice chip if you want to play your old Tandy games on a newer PC. Check out the Tandem emulator, for example.

II.J.4. What is the pinout for the Tandy joystick?

The pinout for the 6-pin joystick connector is:

    5  X  1
       6
    4     2
       3
Where:
   1 is Y-axis
   2 is X-axis
   3 is Ground (0V)
   4 is Button 1
   5 is +5V
   6 is Button 2
The pinout for a standard joystick is:
          --------------------------
          \ 1  2  3  4  5  6  7  8 /
           \ 9  10 11 12 13 14 15 /
            ----------------------

    pin     assignment
    1       +5V
    2       stick 1 button 1
    3       stick 1 X-axis
    4       ground (0V)
    5       ground (0V)
    6       stick 1 Y-axis
    7       stick 1 button 2
    8       +5V
    9       +5V
    10      stick 2 button 1
    11      stick 2 X-axis
    12      ground (0V)
    13      stick 2 Y-axis
    14      stick 2 button 2
    15      +5V

II.K. Miscellaneous

II.K.1. Radio Shack no longer sells parts for my Tandy. Where can I get them?

See section IV.G.

II.K.2. When I turn my computer on, it just beeps a lot and refuses to boot. Why does it do that?

BEEP ERROR CODES

It is normal for a XT or AT clone to beep once or twice during the POST test. More that this indicates a severe error. Beep codes are issued as a sequence of three sets of beeps. For example, BEEP {pause} BEEP BEEP {pause} BEEP BEEP is the code represented as 1--2--2. The Phoenix ROM name is listed by each beep code.

      1--1--3  CMOS WRITE/READ FAILURE
      1--1--4  ROM BIOS CHECKSUM ERROR
      1--2--1  PROGRAMMABLE INTERVAL TIMER FAILURE
      1--2--2  DMA INITIALIZATION FAILURE
      1--2--3  DMA PAGE REGISTER WRITE/READ FAILURE
      1--3--1  RAM REFRESH VERIFICATION FAILURE
      1--3--3  FIRST 64K RAM CHIP OR DATA LINE FAILURE, MULTI-BIT
      1--3--4  FIRST 64K ODD/EVEN LOGIC FAILURE
      1--4--1  ADDRESS LINE FAILURE 64K OF RAM
      1--4--2  PARITY FAILURE FIRST 64K OF RAM

      2--1--1  BIT 0 FIRST 64K RAM FAILURE
      2--1--2  BIT 1
      2--1--3  BIT 2
      2--1--4  BIT 3
      2--2--1  BIT 4
      2--2--2  BIT 5
      2--2--3  BIT 6
      2--2--4  BIT 7
      2--3--1  BIT 8
      2--3--2  BIT 9
      2--3--3  BIT 10
      2--3--4  BIT 11
      2--4--1  BIT 12
      2--4--2  BIT 13
      2--4--3  BIT 14
      2--4--4  BIT 15 FIRST 64K RAM FAILURE

      3--1--1  SLAVE DMA REGISTER FAILURE
      3--1--2  MASTER DMA REGISTER FAILURE
      3--1--3  MASTER INTERRUPT MASK REGISTER FAILURE
      3--1--4  SLAVE INTERRUPT MASK REGISTER FAILURE
      3--2--4  KEYBOARD CONTROLLER TEST FAILURE
      3--3--4  SCREEN INITIALIZATION FAILURE
      3--4--1  SCREEN RETRACE TEST FAILURE

      4--2--1  TIMER TICK FAILURE
      4--2--2  SHUTDOWN TEST FAILURE
      4--2--3  GATE A20 FAILURE
      4--2--4  UNEXPECTED INTERRUPT IN PROTECTED MODE
      4--3--1  RAM TEST ADDRESS FAILURE
      4--3--3  INTERVAL TIMER CHANNEL 2 FAILURE
      4--3--4  TIME OF DAY CLOCK FAILURE
      4--4--3  MATH COPROCESSOR FAILURE
Tandy beep codes might not really look like the above, but you still have some kind of hardware problem.

II.K.3. Where can I get diagnostic software for the 1000's?

You can get generic PC diagnostic software at Garbo or Simtel. See section III.G.3. At one time, you could get diagnostic disks from Tandy National Parts.

II.K.4. What is this connector marked "light pen"?

The original 1000, 1000A, HD, and SX had a connector for a light pen. This is not a serial port. It is pretty useless since there are very few light pens around to plug into it. Remember the cassette port on the original IBM PC? Another useless port.

There were two light pens sold for the 1000. The CPT/S color/monochrome light pen (Radio Shack cat. no. 90-2085) sold for $179.95. It could not be used to emulate a mouse. The CPT/S was made by The Light Pen Company, 12500 Beatrice Street, Los Angeles, CA 90066. The WS-250 light pen (cat. no. 90-2069) sold for $199.99. There was a Penmouse program available for it that might enable it to emulate a mouse. Penmouse was originally sold separately for $49.99, though later it was included with the pen. The WS-250 was made by Warp Speed Computer Products, 555 S. Inglewood Boulevard, Los Angeles, CA 90230.

If you have a light pen, it is software-compatible with the PCjr light pen. There are not very many programs around that support a light pen, but there are some. I don't have a list. Consult a book on the PCjr for programming information (the light pen is programmed through the video controller).

II.K.5. I just got a 1000 at a yard sale, and it didn't come with disks or manuals or anything. Where can I get some?

There are some disk sets in the system directory on the Tvdog site and some manuals in PDF format in the documents directory on that site. Tandy DOS 3.2 or 3.3 from the SX or TL disk sets will run on any 1000-series model. MS-DOS 6.22 will run on the later models at least (SL and later), though Tandy DOS may be better (see section III.A.2.). Otherwise, watch eBay for a while or ask in comp.sys.tandy.

II.K.6. What are the jumper/switch settings for my 1000 or my Tandy adapter card?

Some of them may be given in your owner's manual. Check Tandy's support WWW site to find out about the others (see section IV.B.2.).

1000's Tech Notes and Jumper Manual, Volumes 1 and 2 contains jumper/switch settings for all 1000's and Tandy adapter cards (see section IV.D.).

II.K.7. I just got a 1000 secondhand, and it has some expansion card in it that I can't identify. How do I find out about it?

If it's a Tandy card, check Tandy's support WWW site for information (see section IV.B.2.).

Note that the 1000's can use most any expansion card that works in an IBM XT, so the possibilities are nearly endless.

For the original 1000, 1000A, and 1000HD, which were less compatible than later models, several companies marketed custom cards, and those companies are long gone now. Since those systems only had 3 expansion slots, multifunction boards were popular. The boards commonly included a DMA chip, memory upgrade to 640k, a serial port, a clock chip, a PLUS connector for an additional PLUS-type expansion card, and/or EMS memory. Some of these were:

PBJ MFB-1000, sold by PBJ, 5725 Kennedy Boulevard, North Bergen, NJ 07047 (the manual for this one is available online)

TanPak, sold by Hard Drive Specialist, 16208 Hickory Knoll, Houston, TX 77059

Micro Mainframe 4N1, sold by Micro Mainframe, 120 Blue Ravine Road #2, Folsom, CA 95630

Zuckerboard Multifunction Board, sold by Advanced Transducer Devices, 1287 Lawrence Station Road, Sunnyvale, CA 94089

Matthew Electronics Master/Card, sold by Automation Facilities Corp., 6383 Rose Lane, Carpinteria, CA 93013

PCA Multiboard, sold by PCA Technology, 2512 Pegasus Drive, Bakersfield,