AT&T Model M Clone? (KBD 305B)

[BellLabs]

Hi.  I just went to VCF X (Vintage Computer Fest) and bought this beauty for about 20 bucks.





I thought it was a Model M clone at first, but the few threads here suggest that it's a completely seperate keyboard.

Is it possible I could buy an adapter for the serial port to use it as a PS2 or even USB keyboard?

Thanks.

[Venatorious]

Yes it is an IBM clone. This board is buckling spring, just like the model M. I believe that you can use a teensy to convert the keyboard to USB. Ask me if you need any specific questions. Using a Teensy to convert is very easy. I am trying to use a pro micro clone(cheaper than Teensy) to convert a wyse board and I am having some difficulty. Could you open the keyboard up and get a look at the back? I am curious as to what AT&T used to hold the board together. I know that IBM used plastic rivets.

[dorkvader]

Yes it is an IBM clone. This board is buckling spring, just like the model M. I believe that you can use a teensy to convert the keyboard to USB. Ask me if you need any specific questions. Using a Teensy to convert is very easy. I am trying to use a pro micro clone(cheaper than Teensy) to convert a wyse board and I am having some difficulty. Could you open the keyboard up and get a look at the back? I am curious as to what AT&T used to hold the board together. I know that IBM used plastic rivets.

This is excellent advice for a different KB than this one.

This is the less-common AT&T KB305 (model M licensed technology form at&t) taht is not PS/2. I believe it's some kind of serial. good luck converting it, i recommend soldering a controller to the membrane connectors.

great find and total steal for $20

[Snowdog993]

It would probably work just fine with the Colossus controller if it is a Model M matrix.

http://www.clickykeyboards.com/index.cfm/fa/items.main/parentcat/9523/subcatid/0/id/565017

I have the feeling it is!

[JimByr]

I have both variants of the keyboard and you can use the PS/2 cable on the variant that comes with the DB9 connector. I think that AT&T just used a different connector for some of their computers.

[JimByr]

Ander asked me to document the AT&T v305b cable.

Following the wikipedia RJ and PS/2 definitions...

This is a RJ25 (6P6C, 6 position, 6 contacts) to PS/2 cable.

RJ25 numbering - plug from cable end, connector tab down, contacts on top, 1-6 left to right.
(IOW... holding the cable and pointing the male connector towards the socket)

PS/2 male plug facing you as viewed from the socket
center detent
5 - 6
plastic prong
3 - 4
1 - 2
left - right notches

AT&T 305b cable
PS/2 plug to RJ25 6P6C plug
1 - 2 white unused?
2 - 5 red clk
3 - 3 black gnd
4 - 4 yellow vcc (+5v)
5 - 1 green data
6 - nc gray? unused

Triple-checked.

Update... Added wire colors. They are hard to see in the RJ25.

[dorkvader]

I have both variants of the keyboard and you can use the PS/2 cable on the variant that comes with the DB9 connector. I think that AT&T just used a different connector for some of their computers.

wow this is excellent information, thank you for sharing.

I really like the AT&T buckling spring KBs. The two-piece spacebar, the different controller location, the 4p4c to PS/2 cable (used in a few other KBs its almost a standard!) etc. they have a number of improvements over IBM, in my opinion.

[ander]

Thanks for all your trouble, Jim! This will be a welcome reference for anyone with a 305B with a DB9 or missing cable.

[gamebynight]

Hi everyone -- sorry to resurrect such an old thread. I just acquired this keyboard and it's my first vintage. If I find a replacement RJ25 to PS/2 cable, should any one just work or is there something I should look out for. From there, would a standard PS/2 to USB adapter work?