PS/2 Keyboard Hardware Protocol Information? 18
j-r charles asks: "I need to design a 12 key keypad that plugs into a PS2 port INSTEAD of the standard PC keyboard. Does anyone knows the protocol used by IBM, or where to find it?" So why stick with the boring old choices of 88 and 101 keys when you can build your own with as many (or as few) as you like. Has anyone built custom keyboards for their PCs? How difficult was it?
If you can't find, dissect! (Score:2)
1 - ship a converter (like the above, but get a bulk discount from manufacturer) with your unit, much like mouse manufacturers ship a ps/2 -> serial or usb -> ps/2 converter for their hardware. Added bonus of having your keypad work with BOTH the regular and PS/2 plugs
2 - dissect the PS/2 converter mentioned above and learn from it. I don't imagine how it could be that different. Maybe it's as simple as mapping the wires. The converter's only an inch long, so I'm guessing it doesn't have much in there. Then again, I'm not a hardware person, so I don't know.
Easy! (Score:1)
There seems to only be 6 pins, so there's only 64 possible combinations (assuming high-low signals) if the interface isn't serial.
Actually, someone's already seemed to have done this and you can purchase it yourself--just take it apart to find out what's inside. http://www.cwol.com/keypads/MicroPad-632.htm
Here ya go... (Score:3)
http://govschl.ndsu.nodak.edu/~achapwes/PICmicro/P S2/ps2.htm [nodak.edu]
http://www.nti1.com/ps2-prots.html [nti1.com]
http://micro.new21.org/pic/html/tut_ps2/ps2.htm [new21.org]
digikey.com (Score:1)
Check out this page and use the universal encoder with the keypads.
We should rename "Ask slashdot"... (Score:4)
Re:Easy! (Score:2)
Re:If you can't find, dissect! (Score:1)
Customized keyboards (Score:1)
It seems.. intimidatingly complicated. Has anyone tried making a custom keyboard before? I took apart a couple of keyboards a while back, but the circuitry looked a bit complicated. I'd really appreciate stories, advice, whatever. =)
Re:If you can't find, dissect! (Score:1)
Which 12 keys? (Score:2)
I just got through googling stuff like "keyboard emulator", "keyboard port wiring", "dummy keyboard" and stuff along those lines looking for info on what circuitry to add to a passive KVM switch so that I can boot one computer, switch the switch, and boot the second with the first still thinking that it has a mouse, keyboard, and monitor attached.
Didn't find much of what I was looking for but found a bunch of links about game controls and using the integrated circuit in keyboards that send the scan codes to the computer as part of custom game controls.
http://www.google.com [google.com]
well.... (Score:1)
Same thing (Score:1)
What I am doing is taking a p120, butting BEOS on it so it boots in about 10secs, then mounting it in the trunk, with an AC inverter (or does anyone know of a DC to DC inverter that I can use in a AT computer).
For the keyboard, I am going to radio shack, getting a Key-pad like they use on security systems, and basically chopping up an old keyboard. I've read that if you follow the lines on the plastic from the keys back to the controller, you can take it apart an solder in your own lines (make sure you use cat-5 or other high quality line).
then, all I need is a Winamp like mp3 player for BEOS, I mount the pad on my dash along with a on/off switch, and I'm set.
But, does anyone know what size of AC inverter to buy? and can I get buy with a cheap one, or do I need one of the Perfect Sine wave ones? Also, when I wire the on/off switch on my dash, how thik of wire would I need for it? although alternatively, I could just wire that into the line for the inverter between my battery.
Re:We should rename "Ask slashdot"... (Score:2)
Re:If you can't find, dissect! (Score:2)
True, but it sounded like the poster could find specs for AT style keyboards, but not PS/2. Considereing the price on AT to PS/2 keyboards adaptors I can't help but belive that it is just a few wires and no electronics. I would however make sure from one of the adaptors first. (Or just ship with the adaptors)
Re:Customized keyboards (Score:1)
Sounds like an ErgoMagic [google.com], though I think those actually have 3 pieces, with the numberpad separated also.
programmable interfaces are available already (Score:1)
Re:Easy! (Score:1)
The AT and the PS/2 interface is the same, electrically, there are just different connectors.
Re:Same thing (Score:1)
My linux mp3 player is up and playing mp3s in roughly 15 seconds on a cyrix MX2-300 underclocked to 233 (crappy damned hot cyrix chips), so you don't really need BeOS to do that... When I get some more time I'll finish up the distribution so others can use it. It relies on teh Matrix Orbital 20x4 Vacuum Fluorescent display with teh built-in keypad interface. You might look into that, since you just establish regular old serial communication with the display and either write letters or read keypresses (handles up to 5x5 matrix-format keypads, mine's hooked up to an old AM radio with roller switches on what used to be the big old preset buttons).
Regarding the inverter - I use a 300W Whistler inverter (about $60 or so) so I can run a small monitor off of it too. I'd use a DC-DC converter next time, the inversion/conversion is *really* wasteful.
Drop me an email at cdproject @@ dannysauer.com if you wanna know more, or whatever. I'd love to talk with someone about it.