Denial

Wotcha!

When you are writing games or other graphics routines for your VIC-20 you'll sometimes need to compensate for the pixels being rectangular rather than square. My question is:

What aspect ratio do you assume for pixels in your code?

OTOH, the original video circuitry could be considered broken by design: a proper S-Video mod cures that fault and warrants solder work on the mainboard anyhow. :) There's a whole bunch (6? 8?) of different circuits used in different VIC-20s for video, so a one-size-fits-all S-Video mod is never go...

There's also a potential problem if you start plugging in cartridges - I'd guess that some might pull the 5V line down a bit, which might cause stability issues. I can't imagine this is going to work well with a VIC-20 that has the two-prong AC power connector and the built-in voltage regulator/room...

There's also PCBWay.

I've done around a dozen PCBs with JLCPCB without any problems (other than my own design faults).

When checking prices, remember to factor in postage.

How are you isolating the VIC chip from the original video circuitry? How are you connecting the ClearVideo to the VIC chip?

groepaz wrote: ↑Fri Sep 22, 2023 2:35 pm I don't think you'll fry something - but it will not work

It'll work - mostly - if you don't connect anything at all to the 9VAC pins. That voltage is used on the user port for things like RS232 and some modems, and also for the datasette motor.

I don't, but I do have some advice: that connector sees lots of plugging and unplugging action, so be generous when you solder it to the board to give it as much mechanical help as possible!

* Is there any expansion card, or cartridges that use for any purpose the address space $9130-93FF ?. I know that in the doc its says 'future expansion' but is there " anyone " using it ? Victor, my FPGA replacement for the 6560/1, uses many of the addresses in that range (the ones that d...

Yes, I have blatantly stolen the palettes that you contributed to VICE, but neither the VICE hue/saturation/intensity nor the RGB encoding scheme mapped onto what's going on inside Victor particularly well, so what I have are rough approximations of what you determined - you can tell red from blue, ...

Victor can support eight palettes, one of which (#7) is a user-programmable palette. The default palette, #0, is used when the FPGA first loads, so it should be as much VIC-like as possible. To that end, I obtained two identical 7" displays that could take composite NTSC/PAL input, two VIC-20s,...

Also, the 'memory holes' have been used on occasion to probe VIC activity by the CPU (by fetching data remaining on the BD bus due to parasitic capacitances). That is unfortunate - regrettably, I need an area where I can read info back from Victor to do things like reprogram its EEPROM or fetch the...

I've been staring at schematics for a while now, and I'd like something confirming (or, better still, denying). VIC responds to addresses that match the pattern 1001_0000_xxxx_rrrr VIA1 responds to addresses that match the pattern 1001_00xx_xxx1_rrrr VIA2 responds to addresses that match the pattern...

Well, I'd truly advise buying a better cable, but determining what is a better cable and what is just a rubbish expensive cable is a skill that I don't possess - other than to say gold plating is not evidence of quality.

My book arrived the other day - it will be a "working" book, sat in the pile of stuff I laughably call a desk at home and used frequently. Thanks for putting it together and crediting all of us small guys that contributed single-line changes here and there.

Probably better shielding rather than insulation, and that may well improve the signal quality. Sounds like an easy fix!