5 ms·
Sounds awesome and reminds of the good old times. I don't know much about consoles but in the home computer era, a ton of the awesome stuff was accomplished by
by weinzierl 7y ago
Sounds awesome and reminds of the good old times. I don't know much about consoles but in the home computer era, a ton of the awesome stuff was accomplished by clever trickery triggered by interrupts generated by the electron beam.
The Commodore 64 for example could trigger an interrupt at an arbitrary screen position and not just H-blank or V-blank. We used to call these raster interrupts. Graphics on the screen border, simultaneous graphics and text mode, split screen effects, more than 8 hardware sprites and the light pen were all things that were only possible on the C64 because of that capability. If you want to learn about this check out Shallan50k on Twitch, he does awesome streams about these techniques. The Acorn is a good counterexample of a much more powerful machine which lacked the ability to do raster interrupts and that is in my opinion one major reason the Acorn had relatively poor graphics.
- sokoloff 7y agoI cut my teeth on the Atari 8-bits, where we used vblank and hblank interrupts for all kinds of tricks like you described. The inspiration for this solution came directly from that experience. Side note: I was always jealous of the way better sound hardware on the C64. It's also crazy to me to think that I paid probably around $1000 in 1981 dollars (equivalent of $3500 today) to buy an 8-bit computer with 48K of RAM.
- jlarcombe 7y agoYes. It's possible to do on the Acorn but few games at the time took the trouble to do so. It requires very accurate cycle counting. There have been a number of recent demos that take things to the next level though, and someone has even got raster interrupts working on the Electron, which is frankly astonishing: https://www.youtube.com/watch?v=PUl1SGUSkbI https://www.youtube.com/watch?v=PUl1SGUSkbI