Denial

I read, somewhere, of a program that toggles between two values in a sound register to produce frequencies closer to real notes - do any of you know what I'm talking about and where I could get it from?

Something's not firing on all cylinders - Denial has just emailed me to notify me that Mike made that post!

...you might want to take a sharp look at my ellipse routine (snippet taken from one of my example programs for MINIGRAFIK): If you're following in my footsteps, you might need to know that the range of some of those variables is somewhat larger than you'd imagine: For a resolution of 172x184, e(-5...

I'm assuming (MX,MY) is the center point and that A and B are the major and minor radii? What you have here looks very similar to the code I have in Victor, give or take the ellipsy bits. I'll stare at this for a while and see if I can get it going. Thanks! Rounded rectangles would be neat, but that...

I've not been working on Victor, the 6560/61 replacement FPGA, for a little while due to health issues. To break myself back into working on it I implemented some graphics primitives, just for fun. Drawing points, lines, boxes, rectangles, circles and filled circles: https://www.youtube.com/watch?v=...

Thanks!

It's worth noting that 74LS series chips aren't as plentiful as they used to be, and unscrupulous dealers will sell you re-marked 74HC chips (or is it HCT?), claiming them to be LS. They'll often work for the job in hand, but you need the real thing occasionally, especially in crystal oscillator clo...

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...