Denial

For those of you with pachydermal memories, you may recall that I was using an FPGA to develop a replacement for the 6560/61 VIC chip. This project stalled for quite a while because of ill health and another project I wanted to finish. I'm now restarting work on Victor, and the next task is to creat...

Are these available pre-built and firmware flashed?

https://www.instructables.com/Simple-Dc ... rter-Make/ might be a starting point

If you are in Dallas for Vintage Computer Festival South West this year, I'll be demonstrating Victor.

(mod: see www.vcfsw.org)

I don't suppose there exists an expansion cartridge that is one (or preferably more) largest EEPROMs setup to map into the $A000-$AFFF and $B000-$BFFF spaces, but with banking registers so you can select which block of EEPROM appears in each of the ranges?

You could design a cartridge with a SID in it and feed the output back using pin Y so that it comes out through the regular AV DIN connector on the back of the machine.

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...