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Mini-ITX PC in an Atari 800
tgeller writes "As case mods go, this one's not the weirdest, But it has its own retro charm. Musician and geek Andy Hutson slipped a Mini-ITX motherboard into an Atari 800 case... and used an old cartridge as the mouse! Too bad the original keyboard's not functional." This almost makes me want to tear apart my old Apple //c and see what I can make. Almost.
Ok, so putting a modern PC in an old computercase is cool and all, but running modern style software on the actual old computer is much cooler! Check out the Contiki operating system for such old computers (including the Atari 800): it is a multi-tasking graphical operating system with full Internet access (web browser, telnet client, web server!) that runs on a a bunch of different old computers. They even have a web server running on a real Commodore 64.
The guy did not even bother to break out a multi meter and figure out how the oldkb worked.... btw all the good stuff is at www.mini-itx.org
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I don't think so!!!
I am not sure about the Atari keyboard, but I had a Z80 Spectrum +2. The keyboard was not a serial port sending characters sequentially, it was implemented using parallel inputs. I guess you would need a microcontroller to convert the Atari keyboard to a PS2 keyboard.
Mini-ITX site has a lot of links to similar projects:
http://www.mini-itx.com
The Atari itself, if it were working, would undoubtedly have some sort of circuitry that would take the keyboard inputs and stuff them into a buffer of some sort. One would have to know the format of this buffer (ASCII characters maybe?) and then convert them into PS/2 scancodes and stuff those into the ITX's keyboard controller chip. This would undoubtedly require some kind of specialized chip. I'm not a hardware hacker, so I wouldn't be able to do it, but I know people who *would* and I at least understand the theory, or I think I do anyway. (I'm sure someone will correct me if I'm completely talking out my ass.)
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that's what (one of) the guy behind jackypc.com did.
This website is the reference french-speaking site for moding PC.
Here you can see it (it is a 600)
#include "coucou.h"
The toaster has been done:
http://www.mini-itx.com/projects/toasterpc/
Acid House saves Souls
The way any keyboard works is that it makes a short-circuit between two points. In all PS2 keyboards, there is a microcontroller that detects these short-circuits and then sends a "packet" serially to the computer based on a truth table.
Therefore, it would be dirt easy to take appart an old PS2 keyboard, rip off the microcontroller inside and solder the proper "wires" to it so that when a button is pressed on the Atari keyboard, the microcontroller "knows" which letter has been pressed.
The only "hic" here is if the matrix of wires composing the keyboard would differ from modern keyboards. This would be very doubtful as technology tries to be backwards compatible.
Should be a relativly easy mod to make. Both keyboards work on the princaple of pressing a button to short out two contacts. Simply cut the tracks on the Atari keyboard circuit board. Open up a PC keyboard. Pull the chip and mount into a socket (well, mount after soldering). Trace each key to see what pins it shorts together and wire the appropriate key on the atari back to the new socket. If you plan it out before wiring, you can cut down on the amount of wire used (and therefore space used)
Actually, the guy who molested a Commodore SX-64 on the same site did just that. See http://www.mini-itx.com/projects/sx64/ for details - including how he even stealthed all the ports. The day my trusty, still functional C64 dies I might do the same... but for now, I'm more tempted about trying to squuese a MiniITX board into my PSX which died last christmas...
Everything in the world is controlled by a small, evil group to which, unfortunately, no one you know belongs.
The Atari I/O chip (POKEY, for POrts and KEYboard), was fed a row/column matrix from the keyboard, and then read directly by the CPU.
In order to make the keyboard compatible with a PC, you would need a microcontroller that scanned the row/column matrix and then generated the serial data stream that a PC's 8042 keyboard controller wanted to see.
Not really a very difficult task for a hardware guy - a PIC would probably do quite nicely.
I wonder if the guy was able to use the interior potmetal shield of the Atari - the 800 was designed back when "Class B computing device" MEANT something - Atari took no chance that the computer would fail to pass FCC regulations. The 800 was the quietest (in the RF sense of the word) computer I'd ever seen - ANYTHING that could generate RF was on the inside of a eight-of-an-inch thick metal box.
But using a Star Raiders cart as a mouse?!?!
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The answer is easy :)
http://atari800.sourceforge.net/
It works pretty well, I used it to play M.U.L.E. and Koronis Rift some time ago....
You'd just have to reverse engineer the wiring out of an existing PS2 keyboard. Pull out the (section of?) the PS2 keyboard that has the microcontroller (is it an 8041 in an AT, it's an 8048 in an XT) and graft it on the keyswitches on the Atari's keyboard.
PS2 keyboard schematics do exist, i.e. in the techref manual of an IBM brand machine you could find the schematics. Then it's just a matter of translating switch contacts to switch contacts with a lot of #30 wire wrap and fitting it all in the old case (the logic board from the old keyboard, some of which are fairly small).
ditch the non-functional keyboard and put a cherry g84-4100 in there!. it's even available in black. check their keyboard catalogue here : http://www.cherrycorp.com/products/US/keyboards/pd f_file/gen_purpose.pdf (pdf, scroll 2/3 down).
As for the comment "it's a shame they couldn't get the original keyboard to work", ya know, that's the only thing I didn't like about my 800. The keys didn't follow a standard layout, and I wasn't very fond of their feel.
:)
:)
The long nights I spent poking display list interrupts into the 1536 memory block, and making the 8k Atari basic do things it wasn't meant to do. Good old 6502 assembly language. My first tape drive. My first floppy drive. A geek's first love.
Any chance you still have the Microsoft Basic cartridge hanging around? I have mine. Oh the memories.
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