Viewing Issue Advanced Details
ID Category [?] Severity [?] Reproducibility Date Submitted Last Update
07642 Graphics Major Sometimes May 5, 2020, 17:26 May 10, 2020, 08:57
Tester mycophobia View Status Public Platform MAME (Official Binary)
Assigned To Resolution Open OS Linux (64-bit)
Status [?] Acknowledged Driver
Version 0.220 Fixed in Version Build 64-bit
Fixed in Git Commit Github Pull Request #
Summary 07642: truxton2: sprites flicker or disappear during certain (perhaps graphically busy) parts of the game

see above links. sometimes, usually in late stage 5 or late stage 6 of the game, if there's a lot going on graphically then sprites will flicker or disappear. this does not happen in the original PCB, and seems to be a recent bug as I've played this game for over a year in MAME and don't recall it happening until recently.

A fellow player thinks a change made in the following link (at the bottom of the page) could be the culprit:
Steps To Reproduce Reach the spikes section of stage 6 (final stage, shown in video) or fight the stage 5 boss at full power.
I've attached a savestate for the stage 5 boss fight with full power red weapon. I recommend turning on the invinicibility dipswitch and holding down the fire button to see the bug in action.
Additional Information
Github Commit
Regression Version
Affected Sets / Systems truxton2
Attached Files
zip file icon (31,029 bytes) May 5, 2020, 17:26 Uploaded by mycophobia
stage 5 boss fight full power
There are no relationship linked to this issue.
User avatar
May 6, 2020, 12:53
More likely, cammy did this thing on several drivers:
User avatar
May 8, 2020, 07:32
This issue is related to hardware level limitation, Actual PCB has similar problem.
The limitation is need to verification.
User avatar
May 9, 2020, 16:12
from an original pcb recording:
at 46:32 you can see the stage 5 boss fight at full power (like in the savestate I uploaded). there is a bit of flicker but i don't think it's as bad as in MAME currently.
at 52:00 you can see the stage 6 spike section, where again there is a little bit of flicker but not as much as in current MAME. huge clumps of falling spikes don't disappear, none of the horizontal spikes disappear.
User avatar
Senior Tester
May 9, 2020, 16:43
This is fixed in mame 0.222 according to
User avatar
May 10, 2020, 08:57
It's also possible that MAME's sprite evaluation is the wrong way around.
eg. you have max 80 sprites, game tries to place 100 sprites, and then:
PCB: hide sprites 1-20
MAME: hide sprites 80-100

Another possibility is a status bit indicating sprite overflow, the game then reads this and shuffles the sprite ram if there was an overflow