enginuitor
New Member
- Joined
- Dec 3, 2006
- Messages
- 2
A while ago I bought a PET 2001-8 (with the original "Chiclet Keyboard") at an estate sale, and recently I have finally started to try to get it running. With a little work, I have gotten the screen to come on and display garbage. The cassette motor also runs continuously. I have verified, by means of a logic probe, that the power-on reset circuit brings the 6502 reset line high about a second after power is applied. My oscilloscope shows clean power on the +5V bus (as measured at the internal cassette reader connector). I have carefully removed and re-seated every socketed component on the board, with little resulting change in behavior. An hour of swapping SRAMs around (I have three "new", presumably good, spares) also had no useful effect. The ROM chips installed are a "Version 2" set from Skyles Electric Works, which is supposed to make the machine act like the later "N" series models. Unfortunately I do not have another set of ROM chips to try.
Any suggestions regarding how to proceed would be much appreciated. The equipment I have available includes oscilloscopes and a basic logic analyzer.
Thanks!
--
Greg
Any suggestions regarding how to proceed would be much appreciated. The equipment I have available includes oscilloscopes and a basic logic analyzer.
Thanks!
--
Greg