Defect VC-20
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Defect VC-20
Hi to all,
after buying a lot of stuff at eBay, I have two defect VC-20 here.
One with IC in sockets and one with soldered IC's (CR-Version?).
Both have problems with some keys and do not recognize floppy drives.
If anybody is interested, I would send them out in exchange for some VC-20 literature/magazines in english (so it would be VIC-20, I think ).
Just for the curious, I have two defect C=128 here, one with only garbage on screen, the other one (128D) only working in 128-Mode. For some interesting old magazines or commodore books I would send them to anyone.
Schlowski
after buying a lot of stuff at eBay, I have two defect VC-20 here.
One with IC in sockets and one with soldered IC's (CR-Version?).
Both have problems with some keys and do not recognize floppy drives.
If anybody is interested, I would send them out in exchange for some VC-20 literature/magazines in english (so it would be VIC-20, I think ).
Just for the curious, I have two defect C=128 here, one with only garbage on screen, the other one (128D) only working in 128-Mode. For some interesting old magazines or commodore books I would send them to anyone.
Schlowski
Keys and floppies sounds like they have broken VIAs (6522 chips). Since I believe those are interchangable, you could've tried to carefully switch chips and see if something else breaks (or works). I realize removing soldered chips are not easy, but you might want to switch the two in the socketed VIC and see if it works differently.
See http://www.ftp.funet.fi/pub/cbm/maps/Vic20.MemoryMap for technical details which VIA does what. I think if you swap the two chips, the keyboard and disk may work, but not tape, joystick, userport and timers (?!).
6522 chips are also found in the 1541 disk drive etc, as well as loose chips on some second-hand for sale pages. Someone with more technical skill than me (e.g. Lee) could correct me if I'm wrong.
See http://www.ftp.funet.fi/pub/cbm/maps/Vic20.MemoryMap for technical details which VIA does what. I think if you swap the two chips, the keyboard and disk may work, but not tape, joystick, userport and timers (?!).
6522 chips are also found in the 1541 disk drive etc, as well as loose chips on some second-hand for sale pages. Someone with more technical skill than me (e.g. Lee) could correct me if I'm wrong.
Anders Carlsson
Hi Carlson,
un-soldering is totally out of my abilities, I will never forget my one and only soldering experience - I soldered a reset switch onto my first VC-20. It ended up in huge blobs of soldering and only by chance did not connect the complete port
But switching the VIAs in the socketed one is a good idea, I made with switching of keyboards/cases and CPU a working VC-20 from two non-functional VC-20. So I will read about the tasks of the VIAs and try to switch them.
Bye
Schlowski
un-soldering is totally out of my abilities, I will never forget my one and only soldering experience - I soldered a reset switch onto my first VC-20. It ended up in huge blobs of soldering and only by chance did not connect the complete port
But switching the VIAs in the socketed one is a good idea, I made with switching of keyboards/cases and CPU a working VC-20 from two non-functional VC-20. So I will read about the tasks of the VIAs and try to switch them.
Bye
Schlowski
Boray,
I have basically no problem sending the computer on my expenses, but it would be nice to get something in return, maybe a duplicate VIC-20 user manual or something else? I'm not about making profit, but I would like to get my hands on some english literature concerning VIC-20.
Or copy me some pages from magazines, just give me something
Schlowski
I have basically no problem sending the computer on my expenses, but it would be nice to get something in return, maybe a duplicate VIC-20 user manual or something else? I'm not about making profit, but I would like to get my hands on some english literature concerning VIC-20.
Or copy me some pages from magazines, just give me something
Schlowski
I think each subforum (or thread even) can decide if guests are allowed or not.
Regarding the broken VICs, can it be bad seating of the chips (i.e. VIAs) that make it malfunction like the chip was damaged? Of course, the soldered chips shouldn't rise from their fastening.. on the other hand, I remember that these interface adapters tend to be the first thing that breaks if someone plugged in bad equipment into the machine, so maybe it is not surprising if the rest of the computer works?
Regarding the broken VICs, can it be bad seating of the chips (i.e. VIAs) that make it malfunction like the chip was damaged? Of course, the soldered chips shouldn't rise from their fastening.. on the other hand, I remember that these interface adapters tend to be the first thing that breaks if someone plugged in bad equipment into the machine, so maybe it is not surprising if the rest of the computer works?
Anders Carlsson
Nothing left
Hello to all,
there is nothing left from my list, everything's gone, so we can close this thread
Thanks
Schlowski
there is nothing left from my list, everything's gone, so we can close this thread
Thanks
Schlowski