Original post by pontium
Hi all!
I'm very surprised that I found a forum with commodore pet lovers.
I bought a no operating 8296(SK),because it's very difficult to find one.Well,as I saw the computer is really dead.
I started to restore it,and make it operational again.I found a destroyed power stabilizer(usual stuff) but also i found that 2 roms are missing from the board.It's "U9" and "U10" empty sockeds.
With a google search,I found some information and rom images from this chips.
I have willem programmer and I can burn new roms but what kind of roms I have to use to make them work with pet??Any idea??
Sorry for my bad english,I'm Greek...
Thank you for your time
Giorgos
Original post by pet1978
UE9 and UE10 are normally empty and are available for user or 3rd party roms. UE7 and UE8 should have ROMs. UE7 is a 16K ROM containing BASIC and Kernal routines (addresses $B000-$DFFF & $F000-$FFFF), UE8 is the 4K screen editor ($E000-$E7FF & $E900-$EFFF).
UE7 would take a 27128 16K EPROM
UE8 would take a 2532 4K EPROM
UE9 and UE10 would take 2516 2K EPROMS or 2532 4K EPROMS
See schematic: http://www.zimmers.net/anonftp/pub/cbm/schematics/computers/pet/8296/324644-1of9.gif (http://www.zimmers.net/anonftp/pub/cbm/schematics/computers/pet/8296/324644-1of9.gif)
Info on 8296 ROMS: http://www.zimmers.net/anonftp/pub/cbm/firmware/computers/pet/8296/index.html (http://www.zimmers.net/anonftp/pub/cbm/firmware/computers/pet/8296/index.html)
Dave
Original post by pontium
Thank you very very much for your fast reply with this useful information
I'm gonna buy a new stabillizer and test the system.
Original post by pontium
Restored power supply,but:
No "beep" sound on the begining,nothing on screen
Also PLA chip runs extremely hot,I think its broken.Ram seems to be ok with normal temp on all chips
I will follow the pla replacement with gal chip,but I have to built a programmer.Willem does not support gal programming >:(
Thanks again for your help,
Giorgos
Original post by Nils Eilers
You don't need to buy a GAL programmer. If you can program 27C512 EPROMs with your Willem, you can do the PLA replacement with a 27C512 EPROM and an adapter. Take a look at http://www.vic20.de/html/eprom_pla_8296_und_c64.html (http://www.vic20.de/html/eprom_pla_8296_und_c64.html) - sorry, all german.
This fix works great, I used it to repair my CBM 8296-D.
If there are any questions, I'd like to help where I can.