08562: ibm5150 and clones [digger]: EGA card crashes MAME when loading Digger

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
08562	Crash/Freeze	Critical (emulator)	Always	Feb 14, 2023, 16:54	Mar 13, 2023, 01:50

Tester	ICEknight	View Status	Public	Platform	MAME (Official Binary)
Assigned To	crazyc	Resolution	Fixed	OS	Windows 10/11 (64-bit)
Status [?]	Resolved			Driver	pc/genpc.cpp
Version	0.251	Fixed in Version	0.253	Build	64-bit
		Fixed in Git Commit	7daa460	Github Pull Request #

Summary	08562: ibm5150 and clones [digger]: EGA card crashes MAME when loading Digger
Description	MAME stops responding when trying to load Digger if the PC is using an EGA graphics card.
Steps To Reproduce	Just load the game on any PC system equipped with an EGA card, such as pcega.
Additional Information	Might be worth pointing out that I remember having problems getting its graphics to look properly back in the day, on an Amstrad PC. It seemed to load properly (game logic and sounds were there) but 90% of the times the screen was all fuzzy, almost as in old, scrambled pay-TV channels (see https://en.wikipedia.org/wiki/VideoCrypt) but with CGA colors. I think that loading certain other games before this one could get its graphics to display, but I'm not sure which ones (Paratrooper, maybe?).
Github Commit

Flags
Regression Version
Affected Sets / Systems	ibm5150 and clones [digger]

Attached Files

No.21079 Robbbert Senior Tester Feb 14, 2023, 23:40	I tried with pcega and it does indeed completely freeze MAME (not responding). Because there's no mouse, I had to Ctrl-Alt-Delete, choose Task Manager, noticed MAME's power usage is Very High, consuming all the power of one CPU. I terminated it.
No.21154 crazyc Developer Mar 9, 2023, 04:05	It programs the hsync start pos past the entire line length. If I clamp it then the game runs corrupted like vga but that breaks the ega bios self test. The display should be disabled so it would be a black screen rather than hanging.
No.21156 crazyc Developer Mar 13, 2023, 01:49	Fixed by https://github.com/mamedev/mame/commit/7daa46065225ac73d2f5c5d2c16b8f90e711afa9 . Graphics are still corrupt but its not configuring the crtc properly and afaict it only works on cga and compatibles.