Denial

I took another look at the garbled display. It is possible, that the VIC registers are wrongly initialised, so the screen display start address now points to uninitialised memory. For a short explanation, '@' and the checkerboard character are 0 and 255, respectively. You find this two-byte pattern...

Ouch, sorry to hear about the new problems you got. The ram I got was labeled NEC 8402A5 μPD2114LC Those *are* SRAMs. However, I've seen photos of NEC µPD2114LC in the 'net with '-5' behind the type, i.e. 500 ns. If there is no indication of access time behind a hyphen, this most probably means you...

eslapion wrote:

craftsman1234 wrote: The ram I got was labeled NEC 8402A5 μPD2114LC

These chips don't appear to be standard 1k x 4 bit SRAM chips at all.

You should've checked to see if you can find a datasheet for them before plugging them in. You might have damaged your VIC.

Thanks, lets home not. I have some 2114 on the way.

Update. Well I drove from North Denver to Colorado Springs about 90 US miles to check on a Vic-20 several carts, tapes and a 24k Golden Ram Expansion Chassis going for 50 US dollars. Well got there and it was a pawn shop. The owner had owned a Vic-20 and 128 so at least he knew what they were. He wa...

5378 That's in the range of 5120 to 6143, provided by the two chips UE4 and UD4. Furthermore, the sticky bit is located in the upper nibble, so this must be UE4 at fault. I would set a socket and replace it rightaway, no point in further checking with the piggyback method you mentioned. Mike, thank...

two prong power supply O.K., then the 5K internal RAM consist of ten 2114 SRAMs. An additional 2114 SRAM holds the 1K nibbles for the colour RAM, but this one is not affected. If you are using no expansion is the test the same? The program only tests the internal memory in the range 4096 to 8191, n...

two prong power supply O.K., then the 5K internal RAM consist of ten 2114 SRAMs. An additional 2114 SRAM holds the 1K nibbles for the colour RAM, but this one is not affected. If you are using no expansion is the test the same? The program only tests the internal memory in the range 4096 to 8191, n...

If there was a hard RAM fault, the RAM test routine in the OS would end up in an endless loop (blank white screen with cyan border). There are also other types of RAM faults, where the bit cell 'forgets' the correct value, albeit only after a few µs, which would go undetected by the RAM test routin...

I finally picked up two 8k VIC-1110 boards and want to expand one to 16k or higher. Do I understand you correctly that you need to get two of these chips and then leave the other socket empty. The two additional chips will make it a total of 16k. What is the socket size needed? Each extra chip adds...

This "faulty pixel" seems to appear in one specific character so yes, I assume one bit is faulty in the ram between $1000-$1FFF. Thanks, I was hoping not to have to replace any of the Ram Chips. Do you know on an original Vic-20 which of the chip would control this area of memory. It is p...

I have noticed a problem on my Vic-20. Pet keyboard model. http://imageshack.us/a/img32/9253/4nks.th.jpg http://imageshack.us/a/img822/1669/kdr7.th.jpg There is a small pixel that appears on the screen. I first thought that it was a flaw in my Gorf cartridge but once I obtained a 8k Ram expansion I ...

I did! Works great! You even have one left IC footprint if you want to add the 3k RAM section or some ROM upgrade. I did this back around 1994. Never had to modify or repair my boosted VIC-1110 since. I even added a small reset pushbutton. There are hundreds of different brands of 8k x 8 static RAM...

ken wrote:I have had about 10 people from lemon pm me on my ebay store asking what happened to their accounts
and oh I could be so mean about it

I did not. hehe

A big thanks from me as well, works great, although doesn't look too professional, not that I care about that. Does look a lot better with the cover attached of course. I superglued the 74ls08 to the pcb just in case anyone was wondering. Only had a 1k resistor handy, I imagine that should be ok, b...

My name came about in 1984 when I was helping to teach my High School teachers during spring break how to program in BASIC on the Commodore PET's. Good times. They would mess up something in the program and I would help them fix it. The so I became the computer version of a Craftsman tool set. It wa...