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macplus keyboard<->PS/2

macplus keyboard<->PS/2 Troubleshooting 8 posts Jul 5, 2007 — Nov 13, 2007
hi!

i found this on myoldmac.net:

Hello to all pre-ADB Mac Users, I like to announce an open source, open hardware keyboard protocol

adaptor project to connect the MacPlus keyboard protocol and PS2.

With this adaptor, you can connect your original MacPlus-keyboard

to your PeeCee, or you can take a mass-production-PS2-keyboard

to run your MacPlus, if the original keyboard is lost or broken.

The Hardware is based on an low-cost AT89C2051 8051 type

microcontroller and will fit for both, translation from

a PS2-Keyboard to a MacPlus Computer or vis versa from

the MacPlus Keyboard to a PS2-Host.

Note: do not use telephone-headset-cables as keyboard cable!

telephone cables are connected in roll-over mode

while the mac-keyboard cable is straigt-through.

There are two firmware versions available:

kbdbabel_ps2_macplus_8051.asm from PS2-keyboard to the Mac

and

kbdbabel_mac_ps2_8051.asm from the MacPlus keyboard to PS2.

Note: if you want to switch the direction on the adaptor,

you need to change or re-program the micronontroller.

Note2: This adapter may be used as well for Mac 512k / Mac 128k,

when some adaptions on the scancode translation table are made.

Sorry, I did not get my hands on a Mac512k/Mac128k keyboard

to analyze the protocol.

Some documentation about the Mac Plus Keyboard protocol

is available as well (draft, germand keyboard)

http://kbdbabel.sourceforge.net/doc/kbdbabel_dev_doc_macplus_20070606.pdf

Schematic, PCB mask and firmware source code is available here

http://kbdbabel.cvs.sourceforge.net/*checkout*/kbdbabel/kbdbabel/kbdbabel-mac-ps2/89c2051-mac-ps2_sch.eps

http://kbdbabel.cvs.sourceforge.net/*checkout*/kbdbabel/kbdbabel/kbdbabel-mac-ps2/89c2051-mac-ps2_pcb.eps

http://kbdbabel.cvs.sourceforge.net/*checkout*/kbdbabel/kbdbabel/kbdbabel-mac-ps2/kbdbabel_mac_ps2_8051.asm

http://kbdbabel.cvs.sourceforge.net/*checkout*/kbdbabel/kbdbabel/kbdbabel-mac-ps2/kbdbabel_ps2_macplus_8051.asm

The open software is licensed under the terms of the GNU GPL,

schematics and designs under Creative Commons CC-BY-SA 2.5.

More information, and other keyboard adaptors can be found on

www.kbdbabel.org

cu from Cologne, Alexander / kbdbabel
Wow!

This could be really helpful, as I am trying to find a Mac Plus Keyboard... But I may not have to right away.

Thanks!

-funkytoad

You know, I opened up a point of sale keyboard a while back, and it had a reflashable ATxxxx microcontroller in it.

Yay, a Model M on my Mac Plus!!!

Buyer beware funkytoad, I just bought a "used" Mac Plus keyboard and had to repair 12 of it's keyswitches, but it's OK now.

sounds great, more so to connect my mac plus keyboard (i really love it) to other computers.

I'm not sure I get this. I looked around the website and can't seem to find any schematics from which to build the adapter. I would assume that I have to find a way to flash the chip with the downloaded code? Definitely not for the casual user.

Theoretically, one could with this adapter create a Mac Plus to PS-2 adapter, then use a PS-2 to USB adapter to connect the Mac Plus keyboard to a Modern Mac. So it has some very exciting applications.

Am I missing something here?

I'm not sure I get this. I looked around the website and can't seem to find any schematics
Follow the sourceforge link and browse the CVS...

http://kbdbabel.cvs.sourceforge.net/kbdbabel/kbdbabel/kbdbabel-mac-ps2/

The hardware looks pretty easy to build by hand. It uses a Atmel AT89C2051 which uses the 8051 instruction set and is in circuit programmable.

So, not nearly as hard as it could be. :)

Nathan

mp.ls