08744: gx4000 [plotting]: MAME freezes before the game starts

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
08744	Crash/Freeze	Critical (emulator)	Always	Aug 10, 2023, 20:13	Aug 17, 2023, 16:40

Tester	ICEknight	View Status	Public	Platform	MAME (Official Binary)
Assigned To		Resolution	Open	OS	Windows 10/11 (64-bit)
Status [?]	Confirmed			Driver	amstrad/amstrad.cpp
Version	0.257	Fixed in Version		Build	64-bit
		Fixed in Git Commit		Github Pull Request #

Summary	08744: gx4000 [plotting]: MAME freezes before the game starts
Description	After the initial Credits screen, press a button and MAME will freeze.
Steps To Reproduce	-Start emulation, the credits screen will appear -Press Button 1
Additional Information
Github Commit

Flags
Regression Version	0.240
Affected Sets / Systems	gx4000 [plotting]

Attached Files

No.21691 Haze Senior Tester Aug 10, 2023, 22:18	It seems a little more serious than 'crash' as it locks up MAME entirely, requiring the process to be killed.
No.21692 mahlemiut Developer Aug 11, 2023, 08:02	Looks like a timer set to lower PC2 on the 8255 is getting recursively called. Removing the timer adjust in amstrad_ppi_portb_r() fixes Plotting, although I haven't yet tested other games yet. Regression version is 0.240, likely the strobe fix to 8255.
No.21698 Robbbert Moderator Aug 15, 2023, 08:43	I'm not getting a crash, instead it freezes (not responding), and consumes one cpu at high power. Clicking X twice closes it.