03312: ertictac: Game freezes

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
03312	Crash/Freeze	Critical (emulation)	Always	Jul 18, 2009, 11:05	Aug 16, 2009, 01:42

Tester	palindrome	View Status	Public	Platform	MAME (Self-compiled)
Assigned To	R. Belmont	Resolution	Fixed	OS
Status [?]	Resolved			Driver	acorn/ertictac.cpp
Version	0.132u5	Fixed in Version	0.133u3	Build	Debug
		Fixed in Git Commit		Github Pull Request #

Summary	03312: ertictac: Game freezes
Description	I suspect that this problem may have started since the U4 patch which addresses an issue with the ARM opcodes ( TST/TEQ ). In previous versions, ertictac used a hack where by the TST opcode is replaced with a NOP @ 0x3800154. This hack has recently been removed and the game is no longer playable as a result. Indeed if you patch TST with NOP in driver_init memory_region(machine, "user1"))[0x55]=0; game is fully playable again.
Steps To Reproduce
Additional Information
Github Commit

Flags
Regression Version	0.132u4
Affected Sets / Systems	ertictac

Attached Files

No.04650 Haze Senior Tester Jul 18, 2009, 11:48	if you turn off the 'music' dipswitch it works again. might be a problem with the sound emulation (there is none) or overall AA emualtion rather than the ARM.
No.04651 etabeta Developer Jul 18, 2009, 11:53	@palindrome: please try to fill properly fields of the report ;) Moreover, NOPing a CPU instruction is not a fix. At most, you can use it to say that the culprit is somehow related to that instruction.
No.04661 palindrome Tester Jul 20, 2009, 06:08	No problem. I'll be more careful to follow the standard format when raising issues in future
No.04819 R. Belmont Developer Aug 16, 2009, 01:42	The hang is at B700 waiting for the value at RAM location 7c to equal 1, which is a classic "missing interrupt" pattern. The TST instruction in question appears to be checking if the music is enabled (which calls into question the validity of ever NOPing it) and it works perfectly after my recent ARM core fixes. I have "fixed" this by defaulting the music DIP to "off" until we have better Archimedes h/w emulation.