02906: All sets in segaxbd.c: Disassembling more than F0000 crashes MAME with an "Out of Timers!" error

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
02906	Debugger	Feature	Have not tried	Feb 7, 2009, 21:05	Mar 30, 2009, 17:37

Tester	Luigi30	View Status	Public	Platform	MAME (Official Binary)
Assigned To		Resolution	Won't fix	OS	Windows XP/Vista 32-bit
Status [?]	Closed			Driver	sega/segaxbd.cpp
Version	0.129u3	Fixed in Version		Build	Normal
		Fixed in Git Commit		Github Pull Request #

Summary	02906: All sets in segaxbd.c: Disassembling more than F0000 crashes MAME with an "Out of Timers!" error
Description	Attempting to run something like dasm aburner2.asm,0,f0000 crashes MAME with Out of Timers! This happens to all sets in the Sega X-Board driver.
Steps To Reproduce	1. Start aburner2 in debug mode. 2. In the debugger, type dasm aburner2.asm,0,ffffff
Additional Information
Github Commit

Flags
Regression Version
Affected Sets / Systems	All sets in segaxbd.c

Attached Files

No.04092 galibert Developer Mar 28, 2009, 16:08	Rom is only 80000 long. Range 80000-fffff includes a multiple-times-mirrored timer control area. The driver could check for safe access and not twiddle timers when you go in these regions with the debugger, but I'm not convinced we care. OG.
No.04093 Kale Developer Mar 28, 2009, 16:19	-dasm command on the debugger is for disassembling the ROM code (or work RAM in some cases). Using it on i/o handlers/videoram/paletteram isn't it's purpose and it can give unpredictable results, like in this case. For this specific case, the ROM size is 0x80000, so writing "dasm aburner2.dsm,0,7ffff" works fine, writing any boundary beyond that isn't classificable for a bug report but more likely an user's error. Otherwise we should do bug reports like "if I type 'do pc=678512' in Street Fighter 2 the game doesn't work anymore". Closed.

No.04092

galibert

Developer

Mar 28, 2009, 16:08

Rom is only 80000 long. Range 80000-fffff includes a multiple-times-mirrored timer control area. The driver could check for safe access and not twiddle timers when you go in these regions with the debugger, but I'm not convinced we care.

OG.

No.04093

Kale

Developer

Mar 28, 2009, 16:19

-dasm command on the debugger is for disassembling the ROM code (or work RAM in some cases). Using it on i/o handlers/videoram/paletteram isn't it's purpose and it can give unpredictable results, like in this case.
For this specific case, the ROM size is 0x80000, so writing "dasm aburner2.dsm,0,7ffff" works fine, writing any boundary beyond that isn't classificable for a bug report but more likely an user's error.
Otherwise we should do bug reports like "if I type 'do pc=678512' in Street Fighter 2 the game doesn't work anymore". Closed.