Hardware dinosaurs - help needed badly for 700/32 terminal keyboard interface

[SemihBATTAL]

Hello,
I hope I am in the right forum for this question.
We have about 75 HP 700/32 terminal keyboards which we want use as input devices for our quality control points. I have already constructed a PIC board to do the job but I just can not read the keyboard. What I see from the osciloscope is, the keyboard requires 5V power, a 77 kHz 1:3 duty rate clock, and outputs two pulses on two different lines, time between which is dependent on the key pressed. For example, for the left-shift key, there is always 22 clock cycles between these two pulses.
The keyboard contains a single 30 pin chip, "1LR5-0001". But I can't find any information on it.
Any form of help will be greatly appreciated.
Thanks in advance.

Semih BATTAL
Computing Dept. Manager
Edirne Giyim Sanayi A. S.

[Stan Sieler]

Wow...interesting question.

I'm curious why you don't use generic
keyboards (cheap, current, and likely to
be better documented).

Still...if you can't get help here, try
posting on the Classic Computer mailing
list. Some of the members are the kind
of people who'd love a challenge like
this (and some may already have an answer
for you).

http://www.classiccmp.org/cctech.html
is probably the signup for ClassicCmp.

If that doesn't work, email me at
sieler@allegro.com and I'll get info
on the list.

[rick jones]

"I'm curious why you don't use generic
keyboards (cheap, current, and likely to
be better documented)." But probably not nearly as well build as an old-style HP kepboard :)

That said, I suspect, unless it indeed used some "available from other than HP" chips, the "protocol" implemented by the keyboard was probably an HP proprietary thing. Depending on its age, HP might have even fabbed some or many of the chips in there. Whether HP wishes to retain that Intellectual Property or not I've no idea.

[SemihBATTAL]

Hello,

Thanks for your valuable comments.
I think I can state two main reasons for not choosing an off the shelf, cheap etc. solution. The company I work for had very hard times in the past and the budget for purchasing IT equipment was virtually nill. I just had to use what we already had. And for me this became "instinct". It was only four years ago that we switched from our 9000/855, HP-UX 7, Oracle 6 server to an Itanium, HP-UX 11iv2, Oracle 10g server in just one step. We still use many 700/32 terminals on the shop floor, 2562 printers in the print room and an Apollo workstation for serving these HPIB printers, as well as an HP LaserJet III which I have been using since 1990, all still in mint condition. Personally, I am a bit of a collector myself, hate throwing out working equipment no matter how old or outdated they are. At home I still have my Sinclair MK14 and ZX Spectrum, as well as a Schneider 128 and Intel 286 PC all fully functional.

The second point is of course the challenge... The 20 year old waveforms and extremely simple but clever thinking behind them lured me into this re-engineering adventure.

I had a look at classiccmp.org but couldn't find anything in detail, also had a look at a few more links but with absolutely no useful information.

Last night, our electronic technician pointed out that maybe I should investigate the "other" side of the pulses, and he was right. I now know that I was treating a pulse as the starting pulse whereas it is in fact the finishing pulse. Ie. the 22 cycles mentioned in my original post are the "leftover" pulses of the pulse train, the information is in the pulses prior to this marking pulse. I have modified my PIC program acordingly but no success yet.

If you have come this far reading, thank you for your time... And I am sorry about my diminished command of English...

I will post again here if and when I get it working and would be happy to pass the details to anyone? who may need them.

Semih BATTAL

[Stan Sieler]

Semih,
Can you email me offline?
(sieler@allegro.com)

BTW, I agrew with the concept of saving old
computers. I volunteer at the Computer History Museum (www.computerhistory.org), the
largest computer museum in the world.

[rick jones]

Semih - if what you have is a "diminished command of English" you are far and above many ostensibly native speakers one finds "on the net." You have no cause to apologize.

I've asked around internally and the concensus from those who are still around from that time is that the chip is almost certainly an HP chip not an industry chip, so short of an "ERS" (External Reference Specification) write-up appearing from the dusty recesses of someone's filing cabinet, and receiving aproval to be distributed outside HP, you are likely indeed left to your reverse-engineering skills and help you can find from now non-HP folks. Best of luck with all the "it does this when I press these keys in series or together etc etc" work.

An equally long shot is that the IP (Intellectual Property) for that chip went to Agilent in the split. Whether there would still be anyone at Agilent who knows about it, or if it was spun-off from Agilent as well as they divested some businesses over the years I've no idea.

[Stan Sieler · Accepted solution]

A friend from ClassicComp asks:

1) Has he opnened up the keyboard, if so, what's inside (microcontroller,
HP custom chip, SSI/MSI chips)?

2) How did he make that above measurents ? If it was by connecting a
'scope or logic analyser onto the cable between the terminal and the
keyboard, how does he know which direction the signals are in.

The point being there is a fairly well-known HP keyboard interface, used
with modifications on several machines, which has the following 5 signals :

Power (may be +5V or +12V)
Ground
Clock (but a lot slower than 77kHz normally) (from host to keyboard)
Reset (from host to keyboard)
Data (from keyboard to host).

The basic protocol is that pulsing 'reset' clears an internal counter in
the keyboard and selects the zeroth 'key'. Each pulse on 'clock' moves on
to the next key in the sequest. And the data line indicates whether the
currently-selected key is pressed or not.

This sounds remarkably like the signals he's observing (hence the delay
between the 2 pulses being dependant on which key is pressed). But
normally only one signal is 'from' the keyboard.

I do know that HP used a similar interface for the touchscreen unit in
the HP150 (original version), but in that case the 'reset' (or 'sync')
signal was output from the peripheral (touchscreen logic) and an input to
the host. I have never come across this being used for a keyboard, but
it's clearly possible.

Other things. What happens if you hold down several keys at the same time
(multiple pulses on the 'data' line)?

Is the 'reset' / 'sync' pulse always present, even if no keys are pressed?

What lines have signals on them if the terminal is powered up with no
keyboard connected ? (this _might_ indicate the direction of the signals).

Stan.

[SemihBATTAL]

Hello,

Please accept my sincere thanks for all the useful feedback, and the friendliness you have put into your comments.

Mr. Sieler,
Thank god you were "a few hours late"... Please don't misunderstand, I spent the whole of last night and most of today to get the protocol working and finally got it right. Reading your "complete and accurate description of the protocol" would have taken away all my joy, had I read it before solving it myself... About the 77 kHz clock "seeming too fast", although I have been working on a single terminal/keyboard combination, this was what I measured on the scope and all seem to work ok at this frequency, moreover, having written some parts of the prototype PIC code in "polling mode", I wish the clock could be run even faster.. I will try a few more 700/32's to see if they all work around this frequency.
About ClassicComp's two questions: 1 - it is a 30 pin chip marked 1LR5-0001, that can can be readily sourced from China, but I could find absolutely no technical information about it.
About question 2: I didn't know for sure which direction the signals were going, I was only trying to make educated guesses and I found that these were not educated enough, when our techie suggested that maybe I should be paying attention to the "other" side of the pulses..
I will send you my email addresses in a few minutes..

Mr. Jones,
I have always been afraid of "saying what I did not mean" in a foreign language. Thank you for your comments, I hope I continue saying the right words... But I would appreciate being corrected.

And lastly, I hope I am not hurting anyone's IP by this necessary reverse-engineering component of our small project. I see it like this: my company purchased these terminal/keyboard sets 20 years ago and decided to use the terminal part with barcode readers on the shop floor, and the keyboards as simple Quality-Control input devices. We are not re-producing or re-selling anything containing someone else's IP. Perhaps an HP legal department official comment on the legality or otherwise of such thinking.

Again, if you have come this far reading, thank you vey much for your time. For me, it's been great talking to and listening to much more knowledgeable colleagues.

Semih BATTAL

[Stan Sieler]

Glad you solved it!

If you want to assign any points, I'm sure
Rick and I would both appreciate it :)

I'll let my friend (Tony) who gave me the
info know you had some success.

BTW, I feel that the separate sale of the keyboards (and they *were* separately priced and sold) implies usability, which in turn
means you can reverse engineer them if
you need to. Of course, I'm not a lawyer :)

(I don't know if any programmer can become
a lawyer and retain their sanity :)

[rick jones]

I too am not a lawyer, and will often err on the side of excessive caution in areas that might cause them to become involved, for apart from my dentist saying "You need a root canal" the only other words that can send a chill through my soul is "You are requested to provide a deposition" :)