02580: dirtfoxj: Game freezes immediately after the race start countdown.

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
02580	Crash/Freeze	Critical (emulation)	Always	Oct 19, 2008, 17:46	Feb 9, 2012, 11:59

Tester	Phil Bennett	View Status	Public	Platform	MAME (Self-compiled)
Assigned To	Phil Bennett	Resolution	Fixed	OS	Windows XP/Vista 32-bit
Status [?]	Resolved			Driver	namco/namcos2.cpp
Version	0.128	Fixed in Version	0.145u1	Build	Normal
		Fixed in Git Commit		Github Pull Request #

Summary	02580: dirtfoxj: Game freezes immediately after the race start countdown.
Description	Noticeable screen flicker.
Steps To Reproduce
Additional Information	The problem appears to be a stuck master CPU 'POSIRQ'. The C148 interrupt level for POSIRQ is changed to 0 as soon as the race begins but any previously asserted POSIRQ isn't cleared.
Github Commit

Flags
Regression Version	0.127u1
Affected Sets / Systems	dirtfoxj

Attached Files

No.04731 hap Developer Jul 29, 2009, 19:42 edited on: Jul 30, 2009, 15:07	I'm pretty sure this game doesn't use POSIRQ at all. edit scrap that.. it does use it at game start, 224 times per frame, for a 'spotlight' effect I assume it's due to wrongly implemented POSIRQ: generating one always if level !=0 seems illogical to me. I've searched for a POSIRQ enable/disable bit everywhere, but couldn't find it. :(
No.08164 Phil Bennett Developer Feb 9, 2012, 11:59	I've changed the C148 behaviour so that writing an IRQ priority register clears any previous interrupt state. Ideally we need to run tests on actual hardware to figure out the C148's quirks.