Re: TransWarp GS repair questions

[STYNX <stynx@gmx.de>]

Am Donnerstag, 18. Oktober 2012 07:57:36 UTC+2 schrieb Conrad:
> I shortened the cable and it performs better now. Its still failing tests and starting with the failure screen and crashing constantly but through my convoluted way of enabling the card I was able to get taifun boot a few times and even a desktop once. I think could be a combination of cpu cable, crap power supply, and early ROM revision. At least I'm getting somewhere...

Hi There,
I had a dead TWGS myself. The Problems i encountered were:

old CPU: If you CPU has a speed rating lower than 14, you should replace it. The older CPUs are buggy as hell. The newer 14mhz 65c816 are fully compatible.

bad Oscillator: I had to try several oscillators until the card worked. My ZIPs were a little more picky but same there. Since you get the errors (which ones?) - no Problem there.

cracked solder joints: especially on the Cache-header the GAL-sockets and the CPU-socket. Resolder them if you notice any bad joints. You could use a wooden stick or a plastic-rod to slightly prod on problematic regions.

bad Cache: Thats a real Problem! You would have to replace the 0.6" Cache modules with 0.3" ones. I had to try several brands to get some working. 15ns 256kbit  Winbond or Toshiba worked the best for me.

wrong GALs: The GALs are there to compensate bugs in the old 65816 (up to 10mhz) and should only matter if you leave the old CPU in the TWGS. (which you shouldn't)

Don't just solder around (which i did at first) try reseating the socketed ICs first. Soldering should be the last option.

-Jonas