03492: hunchbkg: Does not boot

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
03492	Crash/Freeze	Critical (emulation)	Always	Oct 28, 2009, 17:27	May 13, 2010, 10:56

Tester	Luigi30	View Status	Public	Platform	MAME (Self-compiled)
Assigned To	couriersud	Resolution	Fixed	OS	Windows XP (32-bit)
Status [?]	Resolved			Driver	galaxian/galaxold.cpp
Version	0.134u4	Fixed in Version	0.138	Build	Normal
		Fixed in Git Commit		Github Pull Request #

Summary	03492: hunchbkg: Does not boot
Description	hunchbkg fails to boot and makes a horrible noise out of the speakers instead.
Steps To Reproduce
Additional Information
Github Commit

Flags
Regression Version	0.134u1
Affected Sets / Systems	hunchbkg

Attached Files	hunchbkg-s2650-0134-0134u1.png (14,386 bytes) Mar 12, 2010, 22:33

No.05863 M.A.S.H. Senior Tester Mar 12, 2010, 22:33	Couriersud improved the S2650 CPU in MAME 0.134u1. I compare the changes made for the S2650 CPU and found that CHECK_IRQ_LINE changed to s2650c->icount -= check_irq_line(s2650c). There are 3x CHECK_IRQ_LINE in MAME 0.134, but only 1x in 0.134u1 (see compare picture). hunchbkg boot/works if you added to the last a check_irq_line (see cursor in compare pic). Added to MAME 0.137 src\emu\cpu\s2650\s2650.c line 857: s2650c->icount -= check_irq_line(s2650c); The bug must be assign to Couriersud!
No.06052 couriersud Developer May 7, 2010, 21:08 edited on: May 7, 2010, 21:10	The interrupt handling in the s2650 core is fine and follows the specification. The game primarily fails due to using "pulse" interrupt calls. The irq line for 2650 is a level line, i.e. an interrupt is raised when the line is asserted. This is completely different from "pulsed", i.e. state change depend lines. Your change would have caused interrupts being taken without having a valid cpu context. This is not in line with how cpu cores should handle interrupts. There is another timing related issue to be reviewed pending right now. Once this has been done, I will submit an improved driver. Interestingly enough, hunchbkg uses the "stars enable" line of the galaxian hardware and enables the scrolling star field.
No.06057 Haze Senior Tester May 8, 2010, 12:33	I think in some cases games enable that line, but it wasn't connected, or was rewired elsewhere...
No.06058 couriersud Developer May 8, 2010, 14:28	The S2650 boards were plugged into the Z80 cpu socket. There are a number of those as well for dkong boards. The stars enable line is decoded on the galaxian main board. I think it would have been an overkill to manually cut it - and it would have rendered the conversion a one way route. Some hires pcb pictures of hunchbkg would help here.