Rolm/IBM 46511 keyboard - and adapter question

[JSchool]

This is a keyboard that came with a Rolm/IBM terminal that I intend to refurbish into a custom case mod project.  I would like to keep the keyboard, since it is actually kind of nice and unique.

Couple questions though:

Will the cable adapter shown on the Unicomp website work with it?  

Since the cable is not detachable, is there any sort of smaller -> PS/2 adapter I can use?  Something without the cable, kind of like a USB/PS2 adapter.

[JSchool]

Well after further investigation it seems like this keyboard might fall under the classification of a "terminal" keyboard and need extensive modification.

http://www.overclock.net/computer-peripherals/676559-ibm-model-m-keyboard-rj-45-a.html

Is this the case?

I don't even own a soldering iron, but I'm willing to learn.  Since this is an ALPS, I'm thinking this might be a good keyboard to wire a new matrix with.  Am I heading down the right path?

[Soarer]

The problem with terminals, is there's lots of different kinds!

The board mentioned on OCN would work with my converter, since for those the signals on the plug are the same as PS/2. (The codes they send are different to a normal PS/2 keyboard though, and need converting).

Your board looks like it would be quite different, assuming that all 8 of those wires in the plug actually do something. Replacing the controller would probably be easier than working out how to convert the signals, especially if you don't have much test equipment handy.

[JSchool]

http://geekhack.org/showwiki.php?title=Island:8406

Are you talking about the process shown there?

Or here:

http://geekhack.org/showwiki.php?title=Island:8028&

Both involve replacing the controller.  I am willing to take on the project and buy the necessary equipment since I will no doubt use it again.


Edit:  You know, now that I think about it, it's really only the keycaps I like.  Anyone know of a small form factor ALPS keyboard?

[Soarer]

Well there's plenty of info in both of those that would be useful to you if you went ahead, but I was thinking more like the first one. As you've probably figured out, the way the switches are wired needs to match the controller, and to my mind it's easier to program the controller than rip off the pcb!!

Another similar project, is hasu's HHKB mod, which uses a Teensy++ as the controller. Still quite a few wires though :-)

[JSchool]

I dunno why but removing the PCB actually looks easier to me.  But since I've never done it before, I'll trust your judgment.  Also, I want to learn how to do this so I can mod other old keyboards with new controllers.  It sounds like a fun project even though I don't have a clue where to start.

Any advice for equipment other than a soldering iron/soldersucker/etc?  What was that test equipment you were talking about?

[Soarer]

Either would work of course! But it seems to me that the programming route is less destructive, and easier to redo (or revert) if it doesn't work right first time - it hardly ever does

I have an oscilloscope and a logic analyzer, but the really essential bit of test equip is a multimeter. It doesn't have to be fancy, although a continuity beeper is very handy for figuring out a switch matrix!

[JSchool]

The magic number seemed to be 13 nickels.

Also included some pics of the chips on the PCBs just in case anyone gets a bright idea on how to simplify the procedure.  

Also, regarding an oscilloscope and logic analyzer, even if they aren't necessary I imagine they would be useful for future projects.  But the console models all seem very pricey - what do you all think of those little portable oscilloscopes?

Like this little thing:

http://cgi.ebay.com/2Msps-Sampling-Rate-ARM-DSO-Nano-Pocket-Oscilloscope-/190466403499?pt=BI_Oscilloscopes&hash=item2c58aeacab

Or if I felt spendy:

http://www.seeedstudio.com/depot/preorder-dso-quad-beta-test-p-736.html?cPath=174

[JSchool]

I'll take a better picture tomorrow (and scale it down for your database).  I literally had to shake nickels out of a piggy bank.  A piggy bank without a trap door on the bottom.  I'll even take a picture of the pig.  

Also added a picture of the PCB.  I don't know a lot (read:  anything) about keyboard matrices but it's there for when I start this project and in case anyone gets a better idea.  Check out the old ALPS logo on the bottom right.

[Soarer]

Ah, seeed... I got my logic sniffer from them, and it works very well! They also have the DSO nano v2 for $89 - the improvements are probably worth the extra $20. And the quad is indeed tempting, with the logic channels and a far higher sample rate, it's a bit more grown-up and probably also worth the extra. I'm sure it would be a very handy tool, but I'm not sure how it would be if it was your only 'scope.

In either case, it's probably better to buy direct from seeed than some ebay cloner!

The 'scope I use is a Picoscope 2203. The software has a great feature - it stores the last 64 screens of capture in memory. So, when developing my converter I could just leave it running, and if there was an error I could scroll back through to see what happened. It made easy what would've been very difficult, if not impossible, with a 'scope that didn't have that feature.

So... keep researching 'scopes but don't rush into one... get a decent multimeter first - a secondhand Fluke from ebay might seem expensive but will last amost forever (I have a 75 and an 87-III, the 75 was actually pretty cheap).

[Soarer]

There seem to be some teething troubles with the DSO Quad's bandwidth. Not sure how that's going to pan out. If it requires a revision to the PCB, it would certainly be worth waiting until that has been done.

I've also seen a couple of mentions of low bandwidth on the digital channels, but haven't found details of it yet.

[ch_123]

I'm not sure where anyone got the idea that this was made by IBM.

Well after further investigation it seems like this keyboard might fall under the classification of a "terminal" keyboard and need extensive modification.

http://www.overclock.net/computer-pe...d-rj-45-a.html

You can tell those posts were made by the guy who wrote the OCN keyboard guide

:3

[Soarer]

Hey, it's a similar looking plug, and hardly anything uses it

[JSchool]

I'm not sure where anyone got the idea that this was made by IBM.

 
Well, I'm basing it on the sticker on the bottom of the terminal.  It says "Rolm, an IBM company."  I dunno how much influence IBM had on the actual design.  It is more computer than phone, though.