Locate chips by number in other stuff?

orion3311

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I'm trying to fix my Area 51 Site 4 board, and I think the main chip on it is fubar. Have a feeling it was overvoltaged at some point. Watchdog is resetting and there's no activity out of the chip anywhere.

Anyone know if the main chip Alctel 42MX09 still available as it came from Atari (or otherwise)? If not, is there any resource to find parts like these in other crap? I know its apparently good for parallel use so maybe it can be found in printers or some other computer junk. I have access to practically endless supplies of computer crap.

Some places actually list it for around $50. A bit much for shotgunning purposes. I think I heard Happ and Betzon fix these things so there has to be parts available. I'm also curious as to what Happ or Betson charge to fix these things (Betson is 10 min from my house) but I have a feeling its more than I care to waste on it.

Chip looks like this:

A42MX09-F-PL84.jpg
 
mouser has them, but unless i'm mistaken, you need to program the fpga for that specific application.
 
That I know, and I can get the programming software from Alctel if I can get someone to download the program off their chip for me maybe. It uses a JTAG port for programming which hopefully I'd be able to rig up somehow.

Now here's another school of thought - correct me if I'm wrong or completely wrong or dear lord what the hell are you thinking wrong....

Area 51 site 4 is two boards in one - half of it is a standard computer motherboard. The other half is the interface half (jammit board). This chip is on the interface half - the computer half boots fine (but had bad ram when I got it).

Would it be totally off base to think that perhaps the computer half downloads firmware to that chip as part of the boot process? And let's say some static charge or overvoltage erased the chip, if I were to somehow disable watchdog long enough for the computer half to boot up - I wonder if that would get it going?

I only say this because I found one old thread on a different board that mentioned someone elses constantly rebooting (watchdog is shared between both boards through a jumper wire), and they fixed it by removing the watchdog wire - it booted, then they put the watchdog wire back on and its good. Now mine's removed so the computer half boots, but the chip is still watchdogging. If I can get the watchdog chip disabled long enough for the computer half to download new firmware - bam Alctel chip comes back to life and stops watchdogging.

Another reason to believe the chip gets programmed on the fly is that there is no rom or data for it in mame. Just the computer's bios rom, and the CHD for the hard drive.

Am I nuts?

The watchdog chip looks for random signal activity for it to stay on, I could just jumper it to anything on the computer half and that (in theory) should get it to stop resetting.
 
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