Is this crazy idea possible? USB (female) to ADB (male)

[2499723]

It's 2015, and increasingly, ADB keyboards and mice are becoming rarer to find, more expensive and, sadly, in increasingly poor condition. With the abundance of USB keyboards on the market, it would be nice to have the opportunity to use a relatively inexpensive, easily accessible USB keyboard on my old Macs. Has there ever been any attempt to create a USB (female) to ADB (male) converter? Or perhaps a PS/2 to ADB converter? Is this an engineering impossibility, or might there be some hope with a bit of effort? Thanks!

 

[keysersoze]

It's 2015, and increasingly, ADB keyboards and mice are becoming rarer to find, more expensive and, sadly, in increasingly poor condition. With the abundance of USB keyboards on the market, it would be nice to have the opportunity to use a relatively inexpensive, easily accessible USB keyboard on my old Macs. Has there ever been any attempt to create a USB (female) to ADB (male) converter? Or perhaps a PS/2 to ADB converter? Is this an engineering impossibility, or might there be some hope with a bit of effort? Thanks!

They were working on PS/2 to ADB for awhile. bbraun said it was on his list I think, after the Plus adapter to PS/2 he got finished (http://www.synack.net/~bbraun/mackbd/index.html), but I don't think he's gotten to it yet. USB to ADB isn't on tap yet, from what I can tell. Here's a thread that died out.

https://68kmla.org/forums/index.php?/topic/16955-skunkworks-ps-2-adb-project/page-3

 

[2499723]

They were working on PS/2 to ADB for awhile. bbraun said it was on his list I think, after the Plus adapter to PS/2 he got finished (http://www.synack.net/~bbraun/mackbd/index.html), but I don't think he's gotten to it yet. USB to ADB isn't on tap yet, from what I can tell. Here's a thread that died out.

https://68kmla.org/forums/index.php?/topic/16955-skunkworks-ps-2-adb-project/page-3

Thanks for the reply. That's useful information. I had an e-mail from Steve Chamberlin, the guy responsible for the incredibly handy Floppy Emu (http://www.bigmessowires.com/macintosh-floppy-emu/), and he pointed me to another thread, which would suggest that the PS/2 to ADB connector might exist in some fashion. I intend on getting in touch with bbraun to see if that's still being worked on. Here's a link to that thread for others who are interested:

https://mac68k.info/forums/thread.jspa?threadID=265&tstart=0&start=0

 

[macEfan]

I believe this is possible, at least with mice. Never tried it with a USB keyboard but it could very well work.

Belkin made a Mac ADB to PS2 adapter back in the late 1990's/early 2000s. From this, you could attach a PS2 to USB adapter and use usb input devices. This is how I got optical mice working on some old quadra machines.

http://cache-www.belkin.com/support/dl/f1d080.pdf

See page 8 of the PDF to see what the device looks like.

 

[2499723]

I believe this is possible, at least with mice. Never tried it with a USB keyboard but it could very well work.

Belkin made a Mac ADB to PS2 adapter back in the late 1990's/early 2000s. From this, you could attach a PS2 to USB adapter and use usb input devices. This is how I got optical mice working on some old quadra machines.

http://cache-www.belkin.com/support/dl/f1d080.pdf

See page 8 of the PDF to see what the device looks like.

Goodness, what I would give for that Belkin adapter! Thanks for the link - at least we know it's been done. It would be nice if we could resurrect that old adapter, though.

 

[desantii]

would be cool!

 

[ScottishCaptain]

You can do this with a modern day microcontroller. I know someone who recently did it using an Atmel AVR developer board running the LUFA library stack to act as a keyboard/mouse host and pipe that data to a classic Mac over ADB. I'll ask him if he wants to share his project notes, but there wasn't much to it- the actual USB <-> ADB code was less then two pages and the actual "adapter" consisted of nothing more then the pre-manufactured AVR board and a ADB breakout cable.

It might even be possible to hack something up using a RaspPi. The key here is that you need something to act as a USB host and pull data off the keyboard, preferably with a set of voltage compatible GPIO pins that you can hookup to ADB afterwards to emulate the codes the ADB system expects on the other side.

-SC

 

[tasrak]

Nevermind, these adapters only convert an ADB keyboard to USB. Some day I may get around to modifying a hobbyist keyboard firmware to convert a USB keyboard to ADB.

The keyboarding enthusiast community has been making these adapters for some time. The TMK keyboard firmware supports ADB, so you can make your own using a development board (such as Teensy) or your own board. Or you can buy them from a poster at GeekHack: https://geekhack.org/index.php?topic=72052.0​