Televideo PC Keyboard Pinout/Adapter

[Polecat]

This is for the Televideo PC (vs. terminal) keyboards, Model 803, 1603, 1605, TPC-I, and TPC-II, possibly others. These keyboards use XT scan codes, but have a 6 pin modular connector and run on 12 volts (vs. 5). So a custom cable will allow them to work on an XT application once the internal 5 volt regulator is bypassed. Scan of my old writeup attached, sorry for my complete lack of artistic skills.

edit: 17 August 2019, please see corrected drawing below!

edit2: 29 May 2022 - It has pretty much been confirmed that this adapter does not work on the TS-803 or other Televideo 800-series computers. Those had an "integrated terminal" and used a 970-type terminal keyboard instead.

[OldIsNew]

Thanks for posting! It seems so difficult in general to find this kind of info!

[orihalcon]

Could you post a picture of what a correctly bypassed voltage regulator looks like on the PCB? Thanks!

[Polecat]

Could you post a picture of what a correctly bypassed voltage regulator looks like on the PCB? Thanks!

Good suggestion, see attached. Sorry about the $3 camera. This is the TPC-II version, but the others are similar. The 7805/78M05 regulator has three pins. Left to right - input, ground, output. Input is 12 volts, output is 5 volts. Cutting loose the two pins and bridging the input and output on the board allows 5 volts to pass through, giving you a 5 volt XT-compatible keyboard. You can remove the regulator completely, but it's easier to reverse this way. I'd suggest labelling the board so it doesn't accidentally get plugged into a Televideo.

[Polecat]

Scan codes from the Televideo TPC-II Technical Reference Manual.

[OldIsNew]

Thanks again! Once again very helpful info!

[Polecat]

Thanks for posting! It seems so difficult in general to find this kind of info!

Thanks again! Once again very helpful info!

Glad to be able to share. I spent a lot of time playing with the Televideo PCs back in the day, and they were an oddball even at the time. Televideo just about owned the terminal market in the CP/M days, but when "personal computers" took over things changed. The Televideo CP/M computers (8 bit/Z80 based - 802, 803, TPC-I, etc) and their corresponding MSDOS ones (16 bit/8088 - 1603, 1605, TPC-II, etc) were well made, but never very popular.

[OldIsNew]

Well I have a TS 804 board, bypassed the VR and have triple checked the wiring but no luck with Soarer's. HID gives output of keyboard ID 00000, PC/XT but no response at all to key presses. I added pull-up resistors and went ahead and changed the electrolytic caps on the board but no change. Interestingly the piezo buzzer does work with every key press - just no HID output. Any thoughts? - should I be using something other than Soarer's?

[Polecat]

Well I have a TS 804 board, bypassed the VR and have triple checked the wiring but no luck with Soarer's. HID gives output of keyboard ID 00000, PC/XT but no response at all to key presses. I added pull-up resistors and went ahead and changed the electrolytic caps on the board but no change. Interestingly the piezo buzzer does work with every key press - just no HID output. Any thoughts? - should I be using something other than Soarer's?

I've never played with a Soarer's Converter, but I just ordered one a couple days ago so I'll soon have one to play with. When I was playing with the Televideo stuff I had a generic XT clone which I ran the Televideo keyboards on (using the above cable) and a Televideo 1605 and TPC-II which I ran XT-compatible keyboards on (using the reverse of the above, with a 5 volt regulator inside the DIN shell). I still have a TPC-II portable (not currently working) and a couple Televideo keyboards, so I'll let you know if they work with a Soarer's once it arrives.

[OldIsNew]

I've never played with a Soarer's Converter, but I just ordered one a couple days ago so I'll soon have one to play with... I still have a TPC-II portable (not currently working) and a couple Televideo keyboards, so I'll let you know if they work with a Soarer's once it arrives.

Thanks, it would be cool to get the board working with the original controller.

[Polecat]

I've never played with a Soarer's Converter, but I just ordered one a couple days ago so I'll soon have one to play with... I still have a TPC-II portable (not currently working) and a couple Televideo keyboards, so I'll let you know if they work with a Soarer's once it arrives.

Thanks, it would be cool to get the board working with the original controller.

The converter arrived, just need to dig out one of my old cables or make up a new one. Probably take me a few days; I'm swamped at work right now, but I'll update with the results ASAP.

[ozzyrulesar]

Hello!.
I've bought a Televideo TPC Senior 2 computer lately. And i'm adapting a XT keyboard for this machine. So i'm doing the inverse job, like adding a LM7805 to the circuit.
I see that you don't connect the "middle pin, 3" on the DIN. But that's seems to be the "DATA" on the IBM PC/XT specifications.

I'm still finishing the circuit, BTW...so i can't say that it's not working.


Thanks.

[Polecat]

Hello!.
I've bought a Televideo TPC Senior 2 computer lately. And i'm adapting a XT keyboard for this machine. So i'm doing the inverse job, like adding a LM7805 to the circuit.
I see that you don't connect the "middle pin, 3" on the DIN. But that's seems to be the "DATA" on the IBM PC/XT specifications.

I'm still finishing the circuit, BTW...so i can't say that it's not working.


Thanks.

Good catch, I mixed up pins 2 and 3 when I did that drawing. The middle pin should be pin 2 and the far left pin 3, and the middle pin should indeed be connected as the data line, not the far left. Sorry for the confusion!

An adapter using a 7805 will indeed work, at least on the TPC2 and the 1603/1605 models. I haven't seen a Senior 2, but hopefully it's the same. I built quite a few of those adapters back in the '90s, and they worked with most PC/XT and clone keyboards. I still have the TPC2 but it's not working at the moment, probably bad caps in the power supply or monitor board. And I have one or two of my old adapters here someplace.

[Polecat]

Let's try this again. Took me 3 minutes to redo the drawing and 45 minutes to get the P1 that runs my ancient scanner to boot. Seems the cat has been back there unplugging cables again.

Again this adapter is to run the Televideo keyboard on an XT connection. You can run an XT keyboard on a Televideo PC by building a cable with a female DIN connector instead of a male. You'll need to use a 5 volt regulator in the adapter or inside the keyboard to drop from 12 to 5 volts. The Televideo keyboards used a 6 pin modular cable, with straight- through connections, so you just need to use a female DIN5 instead of a male on the other end.

[Polecat]

I've been doing some reading online, and one reference says that the 803 keyboard (CP/M) is not compatible with the PC/XT compatible Televideos such as the 1603, 1605, and TPC2. So if that's indeed true the above won't apply to the 803. The 1603/1605 (big gray wedge) and TPC1 and TPC2 (beige and gray latching portable case) keyboards are electrically compatible with each other, and are compatible with PC/XT keyboards other than the voltage difference.

I have personally used XT keyboards on the 1605 and TPC2 using a reverse adapter with a 7805 voltage regulator inline. I built quite a few of those adapters back in the day, and even sold a few to a local dealer who sold and leased Televideo PCs. And I have also used TPC2 and 1605 keyboards on XT clone computers (with a cable adapter) after bypassing the internal regulator. The 803 info above came from a customer in a former life, not confirmed, so that may be bad info. The only Televideo PC I still own is a TPC2, and it's not currently working. I have two of the keyboards for it, one NIB, and also the Technical Manual that came with it, if that helps anyone. Here are a few links with more info on the Televideo PCs. Note that none of the early Televideo terminal keyboards are compatible with the Televideo PCs, which is not a surprise.

http://worldofvax.blogspot.com/2019/01/ ... art-i.html

http://worldofvax.blogspot.com/2019/01/ ... oards.html

http://worldofvax.blogspot.com/2019/01/ ... -pcxt.html

[Polecat]

Doing some spring cleaning and quite by accident stumbled upon my old notes on the Televideo keyboards. Naturally the paper copies survived while the old digital versions are buried on some old PC that probably no longer works. Thank goodness I didn't fall for the "paperless office" propaganda! These notes cover both versions--Televideo computer with XT keyboard, and XT computer with Televideo keyboard. Both are from 1991 or thereabouts.

[Cooccoo]

Hello all!

I am God blessed I find this very useful post!

I have in my collection a Televideo ts 803 z80 based computer in working order. The sad part of the story is that I don’t have the original keyboard.

I read about the (XT to Televideo) adapter that you can simply connect an XT keyboard to the computer. Sadly again I read that this adapter tested and may doesn’t work with ts-803 system.

Are anyone make an other test? Or I will be the first to make a try and post the results?

Thank you very much and of course congratulations for that useful post!

Have a great day all!

[Muirium]

The Teledeity moves in mysterious ways.

[Cooccoo]

Hello again.

Here is my try to connect XT keyboard to my ts 803 that missing the original keyboard.

I just build the adapter but it is not working. With more details, every time I press any keyboard key, system reboot. Any key! LED’s on keyboard working if I press caps or Num lock, but even with those two keys, system reboot.

Here is my adapter:







Here with more details the connections I made:





Maybe I mess the connections, i really can’t figure out the mistake if there is any.

Don’t confuse you the green led i add on the pcb. It is just connected to regulator output to inform me that works.

I will really appreciate any help!

Thank you

[jsheradin]

I will really appreciate any help!

Tidy converter! What cable did you use to connect to the computer? I believe some 6p6c cables have crossovers depending on the equipment they were used with. Might be worth checking the pin order on your specific cable with a multi-meter.

Spoiler:

6p6c.jpeg (41.61 KiB) Viewed 8718 times

Also, if the keyboard has lock lights it's probably an AT keyboard. If it's an AT/XT switchable keyboard double check that it's in XT mode. Usually there's a switch on the bottom. Some are auto-switching but I'm not sure how they'd react to the Televideo.

[Cooccoo]

Thank you! I will check.

I just plug to my converter the original cable that comes from inside the case.

Here:

[jsheradin]

Thank you! I will check.

I just plug to my converter the original cable that comes from inside the case.

Checking +12V and ground should give you a good idea if it's correct.

What keyboard are you using this with? Is it definitely an XT keyboard?

[Cooccoo]

The original 6p6c cable brings the 12v, i check it. That’s 12v+ go to 7805 regulator and drop it to 5v to be able to power the XT keyboard.

Yes I use an XT keyboard that have a switch AT/XT. I have the switch to XT.

[jsheradin]

Last easy thing I can think of: Are you booting the computer with the keyboard connected or hot-plugging? I think the keyboard needs to be connected while powered off for it to detect properly.

[Cooccoo]

Yes. Everything is connected before I boot the system. And as i wrote before, no matter what key I press the system reboot.

[Polecat]

From the first link in the post above it appears the 803 keyboard was not compatible with the TPCI, TPCII, and 1605.

http://worldofvax.blogspot.com/2019/01/ ... art-i.html

That would make sense as the 803 came out before the DOS-based machines, and was probably because the 803 had an "integrated terminal" instead of an onboard keyboard controller. So the 803 might be compatible with some Televideo terminal keyboards.

[Cooccoo]

Thank you for that information Polecat. That’s sad news for me and my lovely ts 803 machine that have it on my hand many years but never play with it cause of the missing original keyboard. When i find that post (yesterday) I was so happy.

Anyway, thank you all very much for your help, I really appreciate it!

Who knows, maybe some day got in my hands an 803 keyboard.

[Polecat]

I'm sorry for the confusion and false hope. I had a TPCII and a 1605 30-some years ago, and I was working with a company that dealt in Televideo stuff. I built some of those adapters which allowed them to use PC keyboards on the Televideos. They also had a special gate array board to bump the memory from 512K to 640K, so I had one of the few TPCII computers with 640K of memory. And a 10MB hard drive, which was a big deal at the time. That was my first DOS computer. The TPCI keyboard worked on the TPCII and vice versa, and the 1603/1605 keyboard would also work on the TPCII, so we assumed the 803 would also work, but that is apparently not true. Or perhaps I'm remembering things wrong from more than 30 years ago. They were surprisingly good computers, but never very popular. I'll resurrect my TPCII one of these days.

[Cooccoo]

No worries Polecat!

You did very nice work with this adapter’s and thank you very much for share all that info! No matter if can’t work for me and my 803. You help many many others! So thank you for that.

The true is that I don’t have the keyboard but I have the pcb only. Damaged, with some missing key switches and keys. I thing I can fix that and maybe put some of the switches and test it. Many traces that need fix and some missing parts. Don’t ask me how that happens. I find it like this and stored it for parts before some years.

[Polecat]

Wow, that's pretty rough, but anything can be repaired if you have the resources and patience. That's enough to identify the layout at least, There's a 1605 on ebay right now with a 970 (terminal) keyboard that looks like the same layout:

https://www.ebay.com/itm/143715760478

They say it's "untested", but I always find that pretty hard to believe. How hard is it to plug in a (standard) power cord and flick the switch? And it's almost as unlikely that the 970 keyboard would work on the 1605. Not only is the layout different, but that's a terminal keyboard, which almost certainly doesn't speak XT protocol. It's much more likely to be the one you need for the 803, but please don't spend a lot of money on one based on that. The case and switches and most of the caps would be the same at least, so the value should be based on that. Since the 803 has an "integrated terminal" it's much more likely to be compatible with the 970 terminal keyboard.

This is the keyboard that originally came with the 1605:

https://www.reddit.com/r/Vintagekeyboar ... eyboard_i/

You can find the Futaba MD switches on ebay if that helps.