PET 2001-N

I bought this PET 2001-N from a collector who was having a clear out. As it wasn't working, I got a pretty tidy deal, but there was plenty to do...

This PET has a 1MHz 6502 CPU, 32KB of RAM on board and the BASIC 2.0 ROM set. The 9" green-screen monitor can display 40x25 characters. Being an "N" model, this machine has a full-size, full-travel keyboard as opposed to the earlier model's "chiclet" calculator-style keypads.

Restoring this PET took quite some effort, mainly because of a nasty video problem which actually turned out to have two unrelated causes. It was however a great learning experience, as I wasn't particularly familiar with CRTs and the analogue electronics which drive them. The full story is documented in the pages below...

17/02/2009: PCB Examination
18/02/2009: ROM Verification
19/02/2009: PCB Repair
05/03/2009: Display Problems
07/03/2009: Fixing The Flickering
08/03/2009: Fixing Horizontal Distortion
09/03/2009: Making Tapes
10/03/2009: Return of the Blank Screen
22/03/2009: Chip Transplant