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Make an iMate?
Posted by: LC_575 on 2011-02-26 14:53:04
I just got my iMate in the mail today and I love it! Right now I'm typing with an Extended II and clicking with a Bus Mouse II, all coupled to a modern computer running Windows 7! Finally, I have a REAL keyboard with proper keys; my typing is so much better because of it. But I digress...

Visually speaking, the iMate appears to be little more than a single chip bridging USB to ADB, along with a series of small capacitors/voltage regulators. If that central chip isn't too proprietary, couldn't we manufacture our own iMate alternative? I ask because the iMate is no longer sold, and nearly always garners high rates on eBay (often well over $50 - mine was a deal at $35), and if that chip is reasonably available and reasonably open, i'm sure with a hobbyist board, and ports ripped from dead equipment facsimiles could be made.

Just a thought.

On a side note, is it me or does the iMate appear to have a battery on it's underside?

Posted by: CJ_Miller on 2011-02-26 17:06:35
It's probably just a microcontroller, programmed to convert ADB protocol into a format that can be recognized on a USB bus. There are some other projects on the web I have seen which adapt various nonstandard keyboard types, the hardware is going to be quite similar. To program it you would need to learn about ADB in detail. It certainly can be done, I am surprised I haven't seen an open project like this happen yet.

Posted by: John Hokanson Jr. on 2011-02-26 21:38:36
I have actually considered the same thing, and it seems within grasp of a homebrew project.

Isn't USB, ADB, AT and PS/2 all 5 volt?

The only issue seems to be signal conversion for the USB pinouts, of which there is likely a crapload of documentation out there sufficient to create a working IC.

This is something people would probably pay for. PC users still love their Model M keyboards as much as we love our Apple Extendeds. There are a number of PS/2 to USB converters.

Posted by: bbraun on 2011-02-26 22:34:53
http://geekhack.org/showwiki.php?title=Island:14290

Looks like keyboard only. No USB HID entry for a mouse, and no ADB passthrough to use other devices like wacom tablets, but a place to start.

Posted by: Bunsen on 2011-02-27 04:19:05
I am surprised I haven't seen an open project like this happen yet.
http://kbdbabel.org/

http://web.archive.org/web/20080305095254/http://xdb2usb.husak.pl/en/

You can also get PICs (and other micros) with USB built in for cheap; then you just have to work out the ADB side.

Posted by: LC_575 on 2011-02-27 17:59:15
Just a slightly off-topic question - is it possible to set up a PC bios in order to respond to the Power Key of an ADB keyboard?

Posted by: ~Coxy on 2011-02-27 19:15:52
If the BIOS has some sort of option for power on from mouse/keyboard activity, then it should be "fairly easy".

If not, then it's still possible, but would require also interfacing your iMate-alike to the power button header on the motherboard.

Posted by: John Hokanson Jr. on 2011-02-27 19:25:28
Converting to PS/2, probably not. It's a pretty rigid (read: slow and dumb) standard, with no provision to carry a "power on" signal. One of the four pins for ADB is specifically earmarked for that purpose.

I keep hearing that PS/2 is at death's door, and yet I still see PCs roll out of factories with the typical green and purple ports.

Guess they didn't get the memo.

If you convert to USB, you could theoretically do it... I think... but only with a fair amount of firmware (BIOS) and hardware (power switch/header) hacking.

Posted by: LC_575 on 2011-02-28 17:32:34
Well, my BIOS (motherboard: ASUS P5QL-PRO) supports "Power on from PS/2 Keyboard" and "Power on from PS/2 Mouse." Nothing about USB.

Hmmm.....

Posted by: John Hokanson Jr. on 2011-03-01 12:55:34
I think that means power on from sleep or some sort of other Energy Star mode. Another common setting is "Power on from LAN." Either way, the motherboard is still hot before it receives input.

I presume you want to start from "cold and dark." Which I've never seen on a PC.

Posted by: gubbish on 2011-03-20 13:22:22
Hi all,

Just came across this thread -

I've been interested in using my Extended Keyboard II with my modern Mac for a while, and recently built an ADB to PS2 converter using an Atmel Microcontroller.

You need a PS2 to USB adapter to use it with a modern computer, but I've been using it for a while and it's been working well.

Here's a picture, it's a little thing, just the MCU, 2 resistors, and 2 cable connectors:



I made a PCB run of a few of these, and was planning to assemble some and sell them on eBay or elsewhere.

If anyone on here is interested, I would be happy to put some of them together and send them to you for cost+shipping. So far it's been working well for me but it would great to get feedback to see how it works for others.

If you would like to build one yourself, I can share the schematic and the MCU code with you to make your own. Total parts cost is under $10 I believe.

Just wanted to share this with you, thanks!

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