VIC-1001 Repair
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- Schema
- factor
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VIC-1001 Repair
I finally got a chance to try out my "cheap" VIC-1001 on a TV that can handle the Japanese NTSC video output, and a North American 9VAC VIC power supply whose output matches that of the original power supply.
It doesn't appear to work
I do get a black screen (not static) with a subtle pattern on it, so at least there is some video signal coming out.
I'm assuming I can follow Ray Carlsen's VIC repair article, but before I get too deep into that, I want to understand the differences between the 1001 and a "normal" VIC20. Is it just the VIC chip, Kernal, and Character ROM that are different?
i.e. I'm wondering if I can move the Kernal and Character ROM onto another VIC motherboard, or move the VIC onto this motherboard, and get a Frankensten 1001 with NTSC output? (Which would be more useful, actually).
It doesn't appear to work
I do get a black screen (not static) with a subtle pattern on it, so at least there is some video signal coming out.
I'm assuming I can follow Ray Carlsen's VIC repair article, but before I get too deep into that, I want to understand the differences between the 1001 and a "normal" VIC20. Is it just the VIC chip, Kernal, and Character ROM that are different?
i.e. I'm wondering if I can move the Kernal and Character ROM onto another VIC motherboard, or move the VIC onto this motherboard, and get a Frankensten 1001 with NTSC output? (Which would be more useful, actually).
Schema,
I have a motherboard from a very early vic that works.
I posted about it here this summer, as it is quite different than
other boards I have seen. Eslapion ( I think) told me it
was basically identical to a 1001 board. Here is a picture
of it :
http://good-times.webshots.com/photo/27 ... 8028hoPZhv
It had a bad 6560, which I replaced after the photo was taken.
All the other chips have 81 dates, except the new 6560.
If you can't repair your original board, you can have this
one for the cost of shipping.
Take your time, this one isn't going anywhere.
Brian
I have a motherboard from a very early vic that works.
I posted about it here this summer, as it is quite different than
other boards I have seen. Eslapion ( I think) told me it
was basically identical to a 1001 board. Here is a picture
of it :
http://good-times.webshots.com/photo/27 ... 8028hoPZhv
It had a bad 6560, which I replaced after the photo was taken.
All the other chips have 81 dates, except the new 6560.
If you can't repair your original board, you can have this
one for the cost of shipping.
Take your time, this one isn't going anywhere.
Brian
If you document it, its not a bug, its a feature.
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You can have peace, or you can have freedom. Just don't count on having them both at once.
~
There was a time, before we were born. If someone asks, this is where I'll be.
- eslapion
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AFAIK, VIC-1001s have exactly the same board (same part no.) as early VIC-20s that use a 2 prong PSU and are "Made in Japan".yoyodyne wrote:... Eslapion ( I think) told me it
was basically identical to a 1001 board.
Distinctive sign: (as on your pic) the 6522s are placed laterally instead of vertically on the board.
On the VIC-1001, many chips have ceramic casings with gold square on top. VIC-20s don't have that.
Pretty much all VIC-20s with PET style keyboard also originally came with the same PSU as the VIC-1001.
Be normal.
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Yup, sure do man!gklinger wrote:I'm pretty sure I gave Centallica such a board at the WoC last year (maybe the year before?) You should ask him if he still has it as it might be just what you need.
It's the one with the botched power supply rig on the side, so you'll have to fix that if you want it?
I hear things people get for free at WOC, some people later sell for a profit? So that'll be $29.95 if you're interested Leif
But, that Chardonay Bloomquist from Sat night in a trade is acceptable, let me know if you want it by Wed 4:30? (As it's in Barrie and I'll be there that night before WOC)
- Schema
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- Schema
- factor
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Standard NTSC has black level at .339vdc while black level for NTSC-J is at .285vdc for composite video.
Check for different bias resistor values around Q7 and compare with standard NTSC pcb.
Apparently you should just be able to turn up brightness pot R7 as an alternative to swapping out resistor values for Q7
Otherwise NTSC and NTSC-J should be same signal format.
Check for different bias resistor values around Q7 and compare with standard NTSC pcb.
Apparently you should just be able to turn up brightness pot R7 as an alternative to swapping out resistor values for Q7
Otherwise NTSC and NTSC-J should be same signal format.
Mega-Cart: the ultimate cartridge for your Commodore Vic-20
The black levels are slightly different, the J variant being slightly lower, so you may have to alter the brightness to get the same image but not by much.Any serious replies?
The other thing is that the channel frequencies also differ but you should be able to use your NTSC modulator with your NTSC-J VIC without any problems. Otherwise you could either retune the NTSC-J modulator, or your TV or bypass the modulator and just use the video out.
Lee.
- Schema
- factor
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- Schema
- factor
- Posts: 1430
- Joined: Tue Mar 23, 2004 7:07 am
- Website: http://www.jammingsignal.com
- Location: Toronto, Ontario
- Schema
- factor
- Posts: 1430
- Joined: Tue Mar 23, 2004 7:07 am
- Website: http://www.jammingsignal.com
- Location: Toronto, Ontario