William McCabe

Are you able to provide the source code for z80rastertimingtest.prg? I note you've also included a timing test for writing to the Z80 IO port!

Attached is a dump of the uninitialized color RAM block from real hardware you're welcome to use however you want in x128. I've used this to "randomize" the color RAM on powerup for Z64K meaning c128modez80-04.prg displays a screen full of colorful characters, just like real hardware! I've tested the latest version of that test on real HW and it pretty much matches Z64K with characters and color for each of those characters.

Thank you Jussi for initiating a more in-depth investigation of the C128 mmu and Marco for all the test programs. A lot of gaps with emulation have been filled for both VICE and Z64K. No other tests that need to be done immediately come to mind at this stage, except, dare I open this pandora's box, is to investigate z80 behavior VICIIe fast mode is enabled. It's something I've always had on my things to do but I'm suspecting that will end up turning into a huge project for another day. :)

I just happened to be working on something else with the real hardware on when I noticed this pop up. :)

Real HW result c128modez80-25.prg - blue border

Real HW result c128modez80-25.prg - blue border

Results from real HW red border for both