Saturday, 23 May 2015

VIC-Emulation finished!

VIC2-Emulation in the Xmega 128 finished:
- refreshrate between 24 and 28 Hz
- userfont with 10 Hz refresh rate
- multicolor, enhanced color, bitmap, multicolor-bitmap
- 38/40 column + 24/25 line with softscrolling
- screen disable, with only short 4us CPU-stops to check if enabled - so jiffy-DOS should work!
- sprites with multicolor, expand x/y, background priority
- sprite-data with about 75 hz refresh
- illegal screen modus
- all CPU-stop are shorter than 30 us / 42 us is OK for disk-loading with normal speed + screen on.
Not implemented: Raster-IRQ, sprite collision detection -> Emulation is possible, but I have to write to ram for this - and now the xmega only reads!
I'm so happy: Loderunner is full playable - it don't uses collision detection ;-)

With Pac-Man I can reach new world-highscores, because I cannot die ;-D
Pipes is full playable - it uses multicolor, but no sprites:

Donkey Kong reaches only the start-screen:
I think many games needs the raster-register!

In Pole Position only the startscreen works.

 I will add the second CIA / 7406 to test some games from disk...

1 comment:

  1. A Vic II replacement with RGB out would be very nice. How difficult would it be to make this into an FPGA drop in replacement for the c64? This would be a great way to connect our c64's to modern screens. Thoughts ?