Weird old keyboard with no identifiable manufacturer

[Maledicted]

Hey guys. Here's a weird one. Any idea what this board is? A recycler on Ebay asked me and I hadn't a clue:

[Findecanor]

It's a terminal keyboard for sure. It has the same layout as early Digital Equipement (DEC) VT-100 series terminals, but it does not look made by DEC.

The key switch looks like Alps SKCC.
Volker-Craig and Televideo used a similar colour scheme.

[Maledicted]

It's a terminal keyboard for sure. It has the same layout as early Digital Equipement (DEC) VT-100 series terminals, but it does not look made by DEC.

The key switch looks like Alps SKCC.
Volker-Craig and Televideo used a similar colour scheme.

Interesting, thank you. Not sure if he's listed it yet or not.

[Maledicted]

Alright. I couldn't help myself. I shot them an offer and grabbed one of the ones that they had. They have at least 3 or so more. You appear to be correct in that they seem to have Alps SKCC cream switches Even with a complete teardown (other than desoldering the switches) I couldn't find any maker marks other than that NEC made the microcontroller.

The connector appears to be RJ11, unlike the quarter inch TRS connectors of the VT-100.



It appears to have a speaker



It has a locking caps lock switch



It has nice thick double shot keycaps. They have yellowed some, so I'm going with ABS on that.



I couldn't find anything identifiable (to me) on it, other than that afformentioned NEC microcontroller.

      

      



Interestingly, this one shows signs of previous repair.

   

[Findecanor]

Interestingly, this one shows signs of previous repair.

I think that cut trace and wire rather looks like a key has been disconnected and bypassed!

[Maledicted]

Interestingly, this one shows signs of previous repair.

I think that cut trace and wire rather looks like a key has been disconnected and bypassed!

Right, that makes sense. I didn't look too closely at it before I uploaded everything. I'm not home anymore at the moment to see what key that may be offhand.

Update: it appears to be the "set up" key that was bypassed.

[Maledicted]

Alright, long story short, I did some more digging and found that it was probably a terminal keyboard made by a company called Micro-Term, whose Ergo 201 terminal (at least) was meant to emulate various terminals, including the VT100. Through further digging/stumbling through the dark I found this post from one of our own:

https://geekhack.org/index.php?topic=88704.0

The guts look identical to mine, so it is probably an Ergo 301 keyboard, which is even more poorly documented on the internet than the Ergo 201 I initially found. He's in the same state, and he also got a Z-150 (like I did) in his own haul, so I suspect these may even be from the same place. I found the OP and asked him about the board, he ended up bypassing the original controller and handwiring it.

I did find the manual and the keyboard has 3-key rollover, it also provides the hex values of all keys when pressed in conjunction with the ctrl key, which I imagine were singled out because of some proprietary layering. The speaker is apparently for at least a carriage return bell, presumably to mimic old typewriters.

I'm not sure if sharing the color coding of the wiring might help shed light on the protocol and/or pinout, but here it is just in case:



Any ideas on where to go from here, if even feasible, if I want to try to preserve the original controller and interface with a modern computer?

[yui]

IBM terminals used RJ11 and a strange ps/2 protocol variant (code page 3), could be the same, if it is the case then a soarer's converter could do the trick, else you will have to find what protocol it uses and look about to see if a converter exists, and if not try to get as much info to make one. or rewire the matrix, but where is the fun in that.

[Findecanor]

Pretty much every terminal manufacturer used modular connectors for keyboards, with proprietary protocols.
The keyboards were typically sold with a terminal, not meant to be interchangeable except as spare parts.
Compatibility was a matter more for the protocol between terminal and mainframe.

[Maledicted]

IBM terminals used RJ11 and a strange ps/2 protocol variant (code page 3), could be the same, if it is the case then a soarer's converter could do the trick, else you will have to find what protocol it uses and look about to see if a converter exists, and if not try to get as much info to make one. or rewire the matrix, but where is the fun in that.

That was certainly my intent, but I have no idea what each wire's purpose is. If it isn't wired exactly like an old IBM or Wyse, I might just get some magic smoke trying to test it. Did any IBM terminal keyboards really use RJ11? The pinout diagrams always seem to just be for RJ45.

There's at least one thread that shows an RJ11 Wyse board that seems to at least have the same color wires ... as the middle 4 on mine:

https://geekhack.org/index.php?topic=52597.100



But that leaves white and blue out entirely, and green for VCC seems a bit odd to me, especially with red/orange being clock.

Pretty much every terminal manufacturer used modular connectors for keyboards, with proprietary protocols.
The keyboards were typically sold with a terminal, not meant to be interchangeable except as spare parts.
Compatibility was a matter more for the protocol between terminal and mainframe.

That's what I was afraid of, especially for a keyboard made as early as 1983.

It does appear that the Micro-Term 450's only documented personality is actually the Wyse WY-50, so maybe they use the same protocol? It does seem that the Micro-Terms were basically all meant for emulating other terminals. The Ergo 301 appears to be focused entirely on the VT100 though.

[yui]

actually thinking of it yeah ibm used the 8p5c version (Rj45 looking connector) and the best way to not have blue smoke would be to trace the signals to a known chip and see where power and ground land. like that big NEC chip, seems to be an intel D8748 replica (pretty common keyboard controller back in the day from what i understand) https://pdf1.alldatasheet.com/datasheet-pdf/view/80208/INTEL/D8748H.html

[Maledicted]

actually thinking of it yeah ibm used the 8p5c version (Rj45 looking connector) and the best way to not have blue smoke would be to trace the signals to a known chip and see where power and ground land. like that big NEC chip, seems to be an intel D8748 replica (pretty common keyboard controller back in the day from what i understand) https://pdf1.alldatasheet.com/datasheet-pdf/view/80208/INTEL/D8748H.html

Thank you for that. I was almost entirely certain that I had done my due diligence, but I still managed to cook a resistor with it wired up to a Soarer's converter.

   

The yellow wire leads directly to various negative leads on components, has continuity with one of each of the contacts on the switches, and has direct continuity with the appropriate ground pins on every chip I bothered to check. Continuity goes cold quickly on the red lead.

   

It leads directly into pin 1 of this voltage regulator, labeled in the spec sheet as "input". The yellow wire has continuity with pin 2, labeled ground in the spec sheet. The white and blue wires are bridged, and connect directly to a bolt that connects to the switch plate. R2 is the resistor that gave up the ghost.



Pin 3 of the aforementioned voltage regulator eventually leads to, and has continuity with, the VCC pin on the SN74LS273N, which has continuity with the VCC pin of the D8748D. Both ground pins on these chips have continuity with every negative lead, including straight back to the yellow wire, that I could identify.

I just guessed on the clock and data wires, figuring mixing those up wouldn't damage anything, but maybe I was wrong? I'm certainly no electrical engineer. I think I did trace the black wire back to something on the D8748D that the spec sheet said could be used for clock, but I didn't necessarily run that to clock on the pro micro. The D8748D should be 5v, but maybe the original power from the terminal was something else entirely?

[yui]

the presence of that regulator rules out ps/2 anyway, it is a 5V regulator and ps2 power is also 5V, so it would be useless and actually detrimental on a ps/2 keyboard (or any other 5v powered bus, like usb) so yeah i would expect your yellow to be ground and red power, from your description white and blue would be shielding. the signalling should be 5V but not the power, it should be higher (although 5V should not have hurt anything) it make sense that clock would go on the clock input, but not in ps/2.
so for me there most likely was a reason why this keyboard was dumped (burnt resistor means that you either sent power backward, too high voltage, that there is a short to ground somewhere or that the resistor was already damaged due to old age)
and it will require quite a bit of trial and error to find the communication protocol, my best guess would be some sort of simple serial communication but still if it is you need to find the encoding, and power the board, which seems to have a default there.

[Maledicted]

the presence of that regulator rules out ps/2 anyway, it is a 5V regulator and ps2 power is also 5V, so it would be useless and actually detrimental on a ps/2 keyboard (or any other 5v powered bus, like usb) so yeah i would expect your yellow to be ground and red power, from your description white and blue would be shielding. the signalling should be 5V but not the power, it should be higher (although 5V should not have hurt anything) it make sense that clock would go on the clock input, but not in ps/2.
so for me there most likely was a reason why this keyboard was dumped (burnt resistor means that you either sent power backward, too high voltage, that there is a short to ground somewhere or that the resistor was already damaged due to old age)
and it will require quite a bit of trial and error to find the communication protocol, my best guess would be some sort of simple serial communication but still if it is you need to find the encoding, and power the board, which seems to have a default there.

This keyboard predates the IBM AT protocol, much less the PS/2 interface. The dates on it all point to 1983. So, you think that the conventional converter will probably be incompatible to begin with due to a higher voltage requirement? When you say the signalling, do you mean clock, or data? Either way, that makes it sound like not mixing those up is more important than I thought. I probably have some resistors of the correct value lying around, I could just swap the cooked one and try to pinpoint clock before trying again. I checked continuity across quite a bit of the board, though certainly not all of it. The shield pins don't seem to be connected to anything else other than the switch plate, the yellow wire is connected to every negative lead on the board that I could test. Continuity of anything else was hard to follow without eying up the traces manually. Physically, I haven't seen anything that looked bridged that should not be.

[yui]

yeah signaling is clock and data, from what you describe it seems that those are not protected and go directly to the main controller, so applying more than 5v to them will most likely hurt it, if not frying it out right.
to fry a resistor like that you need a fair amount of power, more than what the teensy/pro micro can deliver on one output pin, looks to me like a quarter watt resistor so it should handle 50mA no problem all day, if it fried fast i would expect it had the usb power across it, if i read it correctly it should be 1.2k or 270 so even then it should not have heated up, unless you had put more than 600V/135V (respectively) across it for a prolonged period of time...
although if you are planing to power the thing from 5V you could most likely bypass the power circuit completely

[Maledicted]

There are a lot of resistors, capacitors, and diodes where the wires meet the board, most of them run through some of that maze, and I assume at least another regulator (unless they make electrolytic capacitors of some kind with 3 legs) before they reach any of the chips. I would have to look again though.

I have only hooked the board up to a conventionally-configured 5v Pro Micro with Soarer's firmware flashed to it, just like the previous 3 I ordered in the same batch. I left the board connected for probably a maximum of 20 seconds between tests. I do believe 1.2k is the correct rating of the resistor.

What do you mean by bypass the power circuit? Simply not connect the red wire to VCC on the Pro Micro and the clock lead should manage to power the board?

[Quercus]

The sticker on that microcontroller means it is EPROM or UV erasable. That might not be any help, put you could peel the sticker and see the ICs guts for fun.

[yui]

the other 3 leads component i can see the number on is a npn transistor if google is to be believed, and with lead marking of C B and E the smaller 3 leads is also a transistor, why would there be transistors here, i have no ideas, actually i could hazard guesses but it would most likely not help much.

The sticker on that microcontroller means it is EPROM or UV erasable. That might not be any help, put you could peel the sticker and see the ICs guts for fun.

well if the cpu program has not already died out of bitrot that would certainly kill off any chances of it ever working again

[Quercus]

The sticker on that microcontroller means it is EPROM or UV erasable. That might not be any help, put you could peel the sticker and see the ICs guts for fun.

well if the cpu program has not already died out of bitrot that would certainly kill off any chances of it ever working again

Yeah, but isn't the point to bypass it anyway? Even if it is intact, it has proprietary firmware designed to interact with an old terminal. You could yank it and replace it with a new 40 DIP microcontroller, but you'd have to know how the PCB interacts with all of the other obsolete ICs to write valid firmware right?  These are sincere questions BTW, as I don't know squat about this and I'm trying to understand, not give advice.  I know a modern keyboard built from scratch only needs a microcontroller with appropriate firmware on it, switches, wire, and diodes to function. Diodes are only necessary for pressing multiple keys at once, so I can't fathom what all of those other ICs are for, but it's probably not to send a keypress.

[Maledicted]

Yeah, but isn't the point to bypass it anyway? Even if it is intact, it has proprietary firmware designed to interact with an old terminal. You could yank it and replace it with a new 40 DIP microcontroller, but you'd have to know how the PCB interacts with all of the other obsolete ICs to write valid firmware right?  These are sincere questions BTW, as I don't know squat about this and I'm trying to understand, not give advice.  I know a modern keyboard built from scratch only needs a microcontroller with appropriate firmware on it, switches, wire, and diodes to function. Diodes are only necessary for pressing multiple keys at once, so I can't fathom what all of those other ICs are for, but it's probably not to send a keypress.

I would love to get the keyboard working with as few modifications to the board itself as possible, but I know that may not even be feasible. I believe I mentioned further up that the only other person I know of with this same board ended up hand-wiring the switches, bypassing the original controller. All he had was the PCB, plate, and switches though. I figured if I could at least get it wired up properly to a Pro Micro, Soarer's firmware might miraculously at least recognize some key presses. I would love to have the knowledge to decipher keyboard protocols and get them working with modern hardware, but all of that is pretty alien to me. I just fix computers, usually.

All I can guess, having read through parts of the Ergo 301 manual, is that there might be some bizarre hardware-based character layers. The manual makes a big deal out of different modes that the keyboard can operate in.

[Quercus]

This guy claims to have popped all the ICs out and wired in a Teensy on an old terminal. I would think removing the ICs would electrically disconnect the switches. There is very little detail so maybe he jumpered across IC sockets and didn't mention it.

The ATmega328 would fit into the IC socket you have and is capable of controlling a multilayer keyboard. That doesn't solve how the main IC interacts with the board and other ICs and it leaves the physical interface unresolved as well. I tried to follow the traces on my typewriter PCB, but it has multiple layers so one trace would deadend into the PCB and I couldn't tell if it went to the other side or to an internal layer. That's why I'm currently bending diodes in preparation to hand wiring it. Good luck!

[yui]

This guy claims to have popped all the ICs out and wired in a Teensy on an old terminal. I would think removing the ICs would electrically disconnect the switches. There is very little detail so maybe he jumpered across IC sockets and didn't mention it.

The ATmega328 would fit into the IC socket you have and is capable of controlling a multilayer keyboard. That doesn't solve how the main IC interacts with the board and other ICs and it leaves the physical interface unresolved as well. I tried to follow the traces on my typewriter PCB, but it has multiple layers so one trace would deadend into the PCB and I couldn't tell if it went to the other side or to an internal layer. That's why I'm currently bending diodes in preparation to hand wiring it. Good luck!

that is the classic way of dealing with those old keyboard, but some times (especially if working/new) it is nice to have the keyboard in its fully original state, although it is pretty much always more work and if the keyboard is dead anyway pretty much useless (not if shared).
it is also for some peoples fun to try and decipher those old boards, speaking of, you may need an oscilloscope/logic analyzer (i think soarer made one for the teensy) to do that.
personally i am trying to make a HP-HIL converter, that should be much simpler because HP documented the protocol very well, and even made an adapter themselves (incredibly expensive now), just trying to find some of the other hil input devices for cheap to try to make it fully compliant.

[Quercus]

that is the classic way of dealing with those old keyboard, but some times (especially if working/new) it is nice to have the keyboard in its fully original state, although it is pretty much always more work and if the keyboard is dead anyway pretty much useless (not if shared).
it is also for some peoples fun to try and decipher those old boards, speaking of, you may need an oscilloscope/logic analyzer (i think soarer made one for the teensy) to do that.
personally i am trying to make a HP-HIL converter, that should be much simpler because HP documented the protocol very well, and even made an adapter themselves (incredibly expensive now), just trying to find some of the other hil input devices for cheap to try to make it fully compliant.

I haven't made it to O-scope skills yet. I've yet to master the multimeter. I think it would be fun to make something OG stock live again, but for now that would be just geek goals for me. Good luck on the HP-HIL converter!

[Maledicted]

I haven't made it to O-scope skills yet. I've yet to master the multimeter. I think it would be fun to make something OG stock live again, but for now that would be just geek goals for me. Good luck on the HP-HIL converter!

Yes, goodluck. I would love to see a thread with whatever progress you make. I'm in the same boat. I would love to know how to do such things, I do not, and I'm not sure I'll invest the time to change that.

[Quercus]

Maledicted, I think this project and the next one and the next one is how you get there. It's how we all get there. Find a passion and dive deep. People that never stop learning are the ones that keep my hope in humanity alive. The person(s) that made that terminal was/were frying  somebody else's vacuum tubes and transitors figuring it out before us.

[Maledicted]

Maledicted, I think this project and the next one and the next one is how you get there. It's how we all get there. Find a passion and dive deep. People that never stop learning are the ones that keep my hope in humanity alive. The person(s) that made that terminal was/were frying  somebody else's vacuum tubes and transitors figuring it out before us.

Agreed. My day job is as a computer technician, and I learned everything I know about computers by tinkering with old hardware nobody cared about.

[yui]

well on the hp-hil i am still trying to find connectors... and Oscopes are not that complicated, older ones especially given how liltle functions they had, it's just a voltmeter that graphs voltage over time for you, and the old cathode tubes ones can be fed 200 or more volts, so good luck damaging one with keyboard probing (yeah you could always drop it but that is cheating here).

[TheDove]

I have this terminal, keyboard and original manual. Let me know if I can be of any assistance.

Cheers!

[Maledicted]

I have this terminal, keyboard and original manual. Let me know if I can be of any assistance.

Cheers!

All I have is the board. I think I did skim through a manual that's available online. Knowing the exact pinout of the cable would be a start, and maybe what the power specifications may be if they end up being something really strange, as I spent way more time than it should have taken trying to trace the wires in the cable back to the controller to figure out the pinout, and at the end of the day, I burned up a resistor somehow in testing with a Pro Micro.