Reply 20 of 29, by superfury
mr.cat wrote on 2021-03-25, 15:56:
Sounds good :D My "64-bit black screen problem" can be considered solved. I just tried building UniPCemu on a different host and […]
Sounds good 😁
My "64-bit black screen problem" can be considered solved. I just tried building UniPCemu on a different host and it works there just fine.
So I'll have to do some comparison to see what that was about. Could be hw related (Intel vs. AMD etc.), but we'll see.
I'll report back here, if I manage to find out the root cause.
Btw new Tseng card coming up 😁
EXCELGRAPH - ISA Video Display Controller (ET4000/W32i)
Maybe ALEKS has some hints about test software for you?
Hw related depends. When you enable the cpu speed percentage display with the non-working hardware case (setting the setting to 1 and starting the emulator), does the cpu percentage display itself in the top-left corner during the 'black screen'? If so, output is working and the app is malfunctioning at some emulated hardware(CPU, video card etc.).
If the entire app display (save for the title bar and borders) is black, it's indeed either a bug in SDL2 or the app itself. It should always start with displaying some yellow text("Press SELECT to run BIOS SETUP") in the top left corner when it starts. If it doesn't do that, but the normal text at the bottom right displays, it's an emulator startup bug (it's started by the first 10-ish instructions ran on the emulated CPU, using a emulator escape instruction sequence(using some specific port OUT instructions to a specific I/O port)). If that's failing, it will simply run and do nothing(no valid executable code is executing). In that case you'll only see the buttons and keyboard LED display in the bottom right of the window.
If it's actually lighting the floppy LED(A or B), there's probably an emulator hardware(display) or CPU emulation issue at fault.
Pure EGA emulation is still known to be faulty(I don't know yet what's wrong with it atm).
It could also mean a wrong/faulty ROM or missing ROM with the last case (booting but no display).
The very code that displays the yellow text also loads the ROMs after it disappears and resets all emulator components to start using them in a clean system(both CPU and hardware).