iz8dwf | CBM PET 4032 (Universal Board) repair. Finding the only one bad chip! @iz8dwf | Uploaded August 2019 | Updated October 2024, 6 minutes ago.
Commodore PET 4032 "Fat 40", serial n. WG 5378, electronic repair.
One minor issue: chargen ROM not properly inserted in its socket.
One major (and rather intermittent) issue: one bad DRAM chip on D0 line acting bad after it was addressed with A7 = 1.
Thanks to Adrian Black for sending me the diagnostic code!
Editor ROM replacement images (to change the scan frequencies on CRTC PETs for example):
6502.org/users/sjgray/projects/editrom
Commodore PET 4032 "Fat 40", serial n. WG 5378, electronic repair.
One minor issue: chargen ROM not properly inserted in its socket.
One major (and rather intermittent) issue: one bad DRAM chip on D0 line acting bad after it was addressed with A7 = 1.
Thanks to Adrian Black for sending me the diagnostic code!
Editor ROM replacement images (to change the scan frequencies on CRTC PETs for example):
6502.org/users/sjgray/projects/editrom
