Commodore Pet 2001-8 Stopped booting to basic.

[daver2]

Blank screens can occur if a PIA or VIA is faulty and 'jams' a permanent interrupt up the CPU.

Which is why we say, remove all the PIA and VIA devices (if in sockets), then put them back one at a time and test at each step.

When the PIA and VIA devices are back in, use VOSSI to test the IEEE488 port (that was previously reporting as BAD).

Dave

 

[RetroGadgetMan]

Blank screens can occur if a PIA or VIA is faulty and 'jams' a permanent interrupt up the CPU.

Which is why we say, remove all the PIA and VIA devices (if in sockets), then put them back one at a time and test at each step.

When the PIA and VIA devices are back in, use VOSSI to test the IEEE488 port (that was previously reporting as BAD).

Dave

Ah I thought it was reporting as bad due to the pia and via not being in place.
I will test the IEEE488 port. Will do that tomorrow. I just finished putting the Pet back together and it’s still working.

I also have a working composite video out now. I plan on adding a switch to disable the crt for future problems tests so as to avoid the constant power cycles of the pet crt.

 

[daver2]

Yes, it is reporting BAD because the PIA/VIA devices are not fitted.

That is what I said, fit the PIAs and VIA one at a time (making sure that the PET boots up after fitting each device in turn) then fit and run VOSSI to ensure that it reports GOOD.

Dave

 

[Nivag Swerdna]

Spray some contact cleaner into the sockets and consider it fixed!

Merry Christmas!

 

[RetroGadgetMan]

Yes, it is reporting BAD because the PIA/VIA devices are not fitted.

That is what I said, fit the PIAs and VIA one at a time (making sure that the PET boots up after fitting each device in turn) then fit and run VOSSI to ensure that it reports GOOD.

Dave

Ran the vossi test and IEEE does report as bad.

 

[daver2]

So, find the book I recommend (search for Primrose PET and the IEEE488 interface) and enter the BASIC test program (page 188?) to find out which parts of the IEEE488 interface is faulty.

Dave

 

[RetroGadgetMan]

So, find the book I recommend (search for Primrose PET and the IEEE488 interface) and enter the BASIC test program (page 188?) to find out which parts of the IEEE488 interface is faulty.

Is this the one. Unfortunately two of my keys aren’t working so I can’t type it in.

 

[daver2]

Yep, that one.

OK, fix the keys next then...

Dave

 

[RetroGadgetMan]

Yep, that one.

OK, fix the keys next

Yep, that one.

OK, fix the keys next then...

Dave

I have ordered some graphite water based conductive paint to go over the keys. I have two other pets that have the same
Problem.
I will update once this is done and I can type the programme in.

Frank