Viewing Issue Advanced Details
ID Category [?] Severity [?] Reproducibility Date Submitted Last Update
07892 Gameplay Minor Always Mar 1, 2021, 08:48 Jan 15, 2022, 08:03
Tester Augusto View Status Public Platform SDLMAME
Assigned To hackbar Resolution Fixed OS Linux (64-bit)
Status [?] Resolved Driver galaga.cpp
Version 0.229 Fixed in Version 0.240 Build 64-bit
Fixed in Git Commit a6addb1 Github Pull Request # #9141
Summary 07892: sxeviousj: Inserting coin automatically start 2 player game with issues
Description Insert one coin.
Automatically start 2 player game not using the inserted credit.
Solvalou goes totally to left without player input.
When that gameplay end is possible start an new gameplay with correct control input.
To play need insert one coin wait to both 2 player game end or insert coin and after reset.
Only affect sxeviousj.
Steps To Reproduce
Additional Information
Github Commit
Flags
Regression Version 0.221
Affected Sets / Systems sxeviousj
Attached Files
 
Relationships
has duplicate 08129Closed  sxeviousj: "Sol-Valou" moves to the left at the start and the control does not work 
Notes
3
User avatar
No.18502
Tafoid
Administrator
Mar 1, 2021, 11:16
edited on: Mar 1, 2021, 11:17
In particular, work done on April 25, 2020 seems to be the culprit.
Namco custom chip improvements
https://github.com/mamedev/mame/commit/3a6317b0f47a1596777537b7c7544818076f9397

Given the fact that it 'clears up' after the failed start tends to suggest a race condition as mentioned in the source text of one of the custom control chips.
    Note that Xevious has a potential race condition at 0xE9. It checks if
    the control register is 0x10 (chip disabled), then 4 instructions later
    acts on that check. If an NMI occurs between, it can crash.

Why it only affects SXEVIOUSJ, it is unknown. All other tested xevious/clone sets do not exhibit this under testing.
User avatar
No.19178
Haze
Senior Tester
Aug 26, 2021, 13:46
I've noticed a similar issue with xeviousa / xeviousb at least, sometimes you'll insert a coin, it will show FF credits, automatically start a game, and automatically move you to the bottom left (controls don't work) not sure if it's related.
User avatar
No.19642
hackbar
Tester
Jan 6, 2022, 01:04
This is fixed by https://github.com/mamedev/mame/pull/9056 .