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Thread: Tandy 1000HD Keyboard

  1. #21

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    Adapting the other converter would certainly be easier. The question then is, how difficult would it be? The Tandy interface has more pins than a regular XT keyboard...

    On a side note, I copied off the contents of the included floppy disk. Interestingly enough, there are two files on the disk...the XTKBDRVR.SYS file, which the manual talks about, and also an ATKBDRVR.SYS...wonder what that's all about? Assuming there is no risk of damage to the converter, perhaps I should try it with an AT keyboard and see if it works... If anyone wants to take a look at the files (or has an adapter to use them with) - they can be found here - http://www.megley.com/tandy/universa...ardadapter.zip

    Wesley

  2. #22

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    Hate to resurrect an old thread.... but have you identified and dumped the EPROM yet, Wesley? (I'm guessing it's a 2716 - 2K). Barring the inability to get those 74 series chips and the D8039LC (as well as identifying the other components - the caps, transistors, termination resistor?, etc), this is a pretty straightforward job to do in ExpressPCB.

    We'd probably want to start with identifying the components. The board is a very simple board with traces on top and bottom.

    Some experienced person can actually probably look into the 2716's code and see what it's instructing the D8039LC to do. This might help us with reverse engineering it and even cloning it with something like an Arduino.

  3. #23

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    I don't have any way to dump the EPROM. Anything that can be bought on the cheap somewhere to do the job?

    Wesley

  4. #24

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    I don't know if my more modern programmer will dump a 2716 correctly... I had issues even trying to dump a 2732 with it. I do know that Ksarul over in the TI-99/4A forum has some programmers he could try to dump it.

    That 2716 contains the 2K of program code for that processor.... the processor required external memory to run, which is all contained in code on that EPROM

  5. #25

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    OK. Curiosity got the better of me. I got one of these on eBay. Dumped the 2516 EPROM. Out of the entire 2K, 80 BYTES are used to power that translator CPU.

    Now, I hooked a switchable Chicory KB5181 (Keytronics XT/AT switchable) keyboard on there... I can mostly get the keypresses to register on the Tandy 1000, but I get some strange behavior.

    tandy_eprom_contents.jpg
    EPROM Contents

    tandy_keyboard_eprom.zip
    Actual EPROM dump

    I'm assuming that we can likely look at those 80 bytes and disassemble what it's telling that CPU to do pretty easily. Of course, someone that can help decipher the instruction set, which appears to be here: http://121.73.5.55/scamp/scmp.htm (The National 8040 was an early SC/MP CPU.)

    Wesley, I'd love to do a dump of your EPROM to see if it matches mine. Also, can you please attach a zip of the diskette for me? I don't have a working 5.25" drive laying around. Thanks!
    Last edited by acadiel; June 4th, 2016 at 03:04 PM.

  6. #26

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    I don't have any way to dump the EPROM. Based on how it appears to be constructed, I wouldn't think there would have been more that one version of it, but who knows.

    Universal Keyboard Adapter Utilities.zip

    There's the file for you...hope that helps...though it doesn't (based on my limited tinkerings with it) appear to be necessary...perhaps for F11/F12 functionality or something...

    Thanks,

    Wesley

  7. #27
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    I'm going to be so excited if this finally happens and I can use a standard XT keyboard on my 1000TX.

  8. #28

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    Quote Originally Posted by wesleyfurr View Post
    I don't have any way to dump the EPROM. Based on how it appears to be constructed, I wouldn't think there would have been more that one version of it, but who knows.

    Universal Keyboard Adapter Utilities.zip

    There's the file for you...hope that helps...though it doesn't (based on my limited tinkerings with it) appear to be necessary...perhaps for F11/F12 functionality or something...

    Thanks,

    Wesley
    If you ever want me to dump it, or find someone near you that can do it, let me know. I'd love to compare it to mine to see if the program is identical.

    If not, then I can re-burn mine if it's different and see if it solves the issues with the keypresses I'm having with mine.

    Thanks for the disk image!

  9. #29
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    Massachusetts, USA
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    Quote Originally Posted by acadiel View Post

    If not, then I can re-burn mine if it's different and see if it solves the issues with the keypresses I'm having with mine.
    What issues are you having? I am working on a different method to interface a 101 key keyboard to the Tandy, and the only issue I have had is that I cannot get the function keys for Mono Mode, TV Mode, Swap Drives and Low Speed to register on bootup.
    My Retro Computing and Vintage Gaming Blog : http://nerdlypleasures.blogspot.com/

  10. #30
    Join Date
    Jan 2008
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    70 Miles NW of Melbourne, Australia
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    Necroposting, I know. Guilty as charged, however, after waiting for about 3 years for eBay searches to produce fruit I’ve finally purchased a 25-1030 new in the original box with the manual (which I’ll scan and share) for US$110 inc shipping.

    This is significantly more than I wanted to pay but preferable to waiting another 3 years for a bargain that will likely never appear. Vintage computing is no longer a cheap hobby as growing interest mounts.

    Finally, I can use any XT keyboard whilst I’m now going to buy an AT to XT protocol adapter (I have an XT to AT adaptor also), so that I can use my KVM switch with the 1000.
    My Wish List: Vintage Mac SCSI->ETHERNET DaynaPORT LINK T DP0801 Manual, Make-It 486 (or other) 80286 upgrades, Hallock Systems gear / disk images, Copy II PC 'Enhanced' Option Board, Earth Computers ISA Z80 cards & TurboDOS disk. TRS-80 Model IV TurboDOS, Pulsar Little Big Board gear, Tandy Videotext Information System (VIS) for Model 16 Xenix

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