Denial

I'm going to post my findings here on the 6 donor boards I got from the 8-bit Guy. These boards he considered "BER" as a quick assessment he said he did drew him to the conclusion that they would have taken quite the amount of time to repair, and given that he had a 100 or so boards, that ...

Sorry for the delay: /* * It has 9 address lines and 4 data lines * Pin assignment as follows: * D7,D8,D9,D6,D5,D4,D3,D2,A5,A4 are connected to 2114 Address pins (blue wires) * A3, A2, A1, A0 are connected to the 2114 Data pins (yellow wires) * D13 is used for RW (green wire) (LOW = WRITE) * CE (Set...

I hope no one minds, but I'd like to keep this thread going to a solution. I have 4 more boards to go, and lots of spare parts. I wired up an AVR128DA64 (an Arduino Mega would also work - at minimum, this needs lots of digital lines). I also used this circuit to test out my static RAMS. Yup, I know....

Hey Joe!! Sorry to hear that replacing the CPU didn't fix the problem. The scope shots are now on my website (my apologies if I am not supposed to post links): https://www.itdiscovery.info/vic20 I would be happy to take any shots on the board you want and post them, now that my VIC-20 works (at leas...

Update: Replacing the socket and caps didn't help, but the signal still croaked when tapping lightly. Re-flowing R15 and the signal stayed up. I could see that AD0-4 ran after reset and then stopped. That smelled like it was running code, but bogus code. I then swapped back in the original kernel RO...

Being in Texas, I completely empathize with doing your soldering in the heat. My workshop is also sudo outside, and so I am limited to quick sessions before 9AM at the latest. I'm working on posting the first waveforms downloaded from my FNIRSI scope. Since you're new to scopes, duplicating the firs...

Update:

I got garbage on the screen once (random characters), so I think my VIC-1 might be good, or at least intermittant. Progress!!

I'll post my pics to my website: www.itdiscovery.info/vic20...which I will create right now.

Hey USA-Joe!! You must have the darker green (later) RC board. I have found that on the one I have it's really easy to lift traces. Would you like one of the other boards I have? If so, I'd like to trade a test of a couple of VIC-1's I have. I'm pretty sure that's where my problem is. I'll look at p...

Hi USA Joe!! I am in the same predicament, x6. The 8-But Guy kindly gave me 6 VIC-20 boards as part of the VCF Southwest lab he ran. I'm currently focusing on one board where I have socketed every chip but UB9 (the clock generator). I have lots of spares, as I pulled a lot of components off other bo...