The screen only inverts twice in Mini Lights Out (CHIP-8) about drom

[tobiasvl]

Actually, it does invert it more than once, but the subsequent inversions are very slow for some reason.

But the same thing happens in MAME, only a little differently: All the inversions are slow.

[tobiasvl]

Actually, it seems like perhaps the timer in DREAM 6800 works differently than on the VIP!

The timer is decremented every frame by the interrupt, but there's no check for whether it's zero (like on the VIP), so it simply wraps around to $FF. That means that any CHIP-8 game that checks the timer will need to get lucky to check it on the correct frame. Wow!

And the beeper is affected too: When the beeper is on, CHIPOS is actually "halted". The COSMAC VIP would continue the game while the sound was on.

Closing this, but it might be something for my custom CHIPOS version.