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dirkwhoffmann / virtualc64

VirtualC64 is a cycle-accurate C64 emulator for macOS
https://dirkwhoffmann.github.io/virtualc64
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VICII/spritemcbase #671

Closed dirkwhoffmann closed 3 years ago

dirkwhoffmann commented 3 years ago

From the README file:

spritemcbase.prg:
-----------------

dumps VIC registers at startup, installs a "reset proof" program for testing.

press 1-8 to enable sprites

VICE:

Bildschirmfoto 2021-05-04 um 14 38 10

VirtualC64:

Bildschirmfoto 2021-05-04 um 14 38 30
dirkwhoffmann commented 3 years ago

I've looked at this issue in a little more detail. It's about a graphics glitch related to the initial value of the mcbase registers (VICII). However, I have no idea how this glitch is supposed to look like, I don't see anything in VICE.

Anyway, I've adapted what is written in the README file. mcbase is initialized with 0x3F (VICII 65xx) or 0x00 (VICII 85xx), respectively.

I've also implemented a real "soft reset" option, because the test case makes use of that.