Few days ago I bought an untested accelerator card -the PP&S 68040-3000. It doesn't work, the Amiga was showing black screen and the power diode was dimmed. Yesterday I spent some hours with this card trying to find what's wrong. Now I know there is something wrong with one of the PAL chips. When I pulled one of them out, Amiga started and booted system but was working with motherboard 68030 only. The 68040 was inactive. The accelerator has an ability to switch between 68040 or 68030 from motherboard by software. I think this broken PAL is responsible for switching between these two processors.
Is there any solution to make this PAL get back to work? I'm not an programmer nor electronics guy, but I can check the signals running from accelerator's board to the PAL socket. I mean I can check there are no broken paths or resistors or capacitors etc.
http://www.bigbookofamigahardware.co...ct.aspx?id=241
Please, help me somebody!!!
Unfortunately, the code put on PALS were protected by blowing a fuse inside to prevent it from being read. If that PAL is indeed the trouble your only hope may be to find another user with the same board and try and read the pal(hope its not protected) or get the code from the company who made it(good luck here).
There are ways to reconnect the fuse but they are not easy and don't always work.Of course the PAL you have is likely suffering from bit rot and has lost its info,so at a minimum,you may need access to another accelerator. if you can get the code you will need a PAL programmer(or eprom programmer that handles that particular PAL chip).
