eight088
Experienced Member
Hello to everyone
Over the last couple of weeks, I have been working on a pet 3032 which had a bad display board and currently has a few problems with the mainboard. As per my previous threads I was able to get the display working, but the pet mainboard has been giving a little bit of grief, so I'm currently waiting for a programmer so I can make a pettest rom to help with further diagnosing.
Seeing's I have to wait for parts, I decided to turn some attention to the 3016 I got as well. This one also has a bad video display, but I thought I would try the working monitor from the 3032 on the 3016. At first it gave a garbled screen so thought I would check the usual signals on the 6502. Most looked pretty good except for the clock signal out. Looking at the schematics, the clock out feeds a 7417 chip. I suspected the CPU as being bad at first but thought it would be easy to pull it out of its socket, bend up pin 39 and check the signal out just in case it was the 7417 pulling the clock low. I wasn't even sure if this was a proper way to diagnose it, but upon power up the CPU was in fact generating a clock out signal. The screen also came up, but this time it broke out into the built-in machine language monitor. Thinking this looked promising, I put the CPU back in properly and presto! It worked!
I'm so happy to see this working! It was such a simple fix, well sort of - its own vdu needs work and the keyboard needs work as only a few keys are working. However, it's looking very promising to see another working PET in the community! I feel like the knowledge I've gained from here, even though it's been a short while, has helped with getting this PET going. Now I need to do a serious clean on it and try to get it back into pristine condition!
Thanks to everyone who has helped me with my previous posts!
Cheers
Over the last couple of weeks, I have been working on a pet 3032 which had a bad display board and currently has a few problems with the mainboard. As per my previous threads I was able to get the display working, but the pet mainboard has been giving a little bit of grief, so I'm currently waiting for a programmer so I can make a pettest rom to help with further diagnosing.
Seeing's I have to wait for parts, I decided to turn some attention to the 3016 I got as well. This one also has a bad video display, but I thought I would try the working monitor from the 3032 on the 3016. At first it gave a garbled screen so thought I would check the usual signals on the 6502. Most looked pretty good except for the clock signal out. Looking at the schematics, the clock out feeds a 7417 chip. I suspected the CPU as being bad at first but thought it would be easy to pull it out of its socket, bend up pin 39 and check the signal out just in case it was the 7417 pulling the clock low. I wasn't even sure if this was a proper way to diagnose it, but upon power up the CPU was in fact generating a clock out signal. The screen also came up, but this time it broke out into the built-in machine language monitor. Thinking this looked promising, I put the CPU back in properly and presto! It worked!
I'm so happy to see this working! It was such a simple fix, well sort of - its own vdu needs work and the keyboard needs work as only a few keys are working. However, it's looking very promising to see another working PET in the community! I feel like the knowledge I've gained from here, even though it's been a short while, has helped with getting this PET going. Now I need to do a serious clean on it and try to get it back into pristine condition!
Thanks to everyone who has helped me with my previous posts!
Cheers
