Viewing Issue Advanced Details
ID Category [?] Severity [?] Reproducibility Date Submitted Last Update
06762 Sound Minor Always Nov 16, 2017, 08:39 Feb 7, 2020, 09:46
Tester Augusto View Status Public Platform MAME (Official Binary)
Assigned To Resolution Open OS Windows 10 (64-bit)
Status [?] Acknowledged Driver
Version 0.191 Fixed in Version Build 64-bit
Fixed in Git Commit Github Pull Request #
Summary 06762: chelnov: Sound music slowdown when big sprites are on screen and the player has a weapon with multiple shot
Description If big sprites is on screen and the player has a weapon with multiple shot at once the music is slowdown.
Hit multiple shoots in a boss and the music will slowdown.
MAME previous versions before 12-2016 not slowdown the music when bosses are hits with multiples shoots.

The same issue is in current MAME version with Midnight Resistance (several sprites or few big sprites on screen) and Secret Agent (some areas) both slowdown the music being both games from Data East.
Steps To Reproduce
Additional Information
Github Commit
Regression Version
Affected Sets / Systems chelnov
Attached Files
There are no relationship linked to this issue.
User avatar
Nov 18, 2017, 23:18
It has been reported multiple times that Midnight Resistance is plagued with slowdowns on real HW as well, so please stop moaning about it.
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Senior Tester
Jan 25, 2020, 14:27
edited on: Jan 28, 2020, 15:39
This is the original hardware. The only slowdowns I've seen are in 17:10 and 26:38. It doesn't seem to affect the music
User avatar
Feb 1, 2020, 15:47
not sure if this issue still actual. I've did playthrough but haven't noticed music slowdowns, only gameplay slowdowns in few places like 17:10 and 26:38 in above video.
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Feb 4, 2020, 18:58
edited on: Feb 4, 2020, 19:11
I wonder, *if* this is still happening, could it be the same kind of problem as the dec0 driver, as logged in MT #6740? The hardware may be different, but it’s the same developer, so maybe they used similar weird instruction tricks here that MAME is also not emulating.
User avatar
Feb 7, 2020, 06:29
I has tested in 0.217 and the slowdown is less than in 0.191.
Stage 5 Boss and player using the fire weapon in maximum power and speed has slowdown in music and gameplay mainly when the boss attack using 3 little birds, but now is less slowdown than 0.191 and the slowdown is more in music than gameplay.
The slowdown in music is when has big sprites and using an weapong with multiple shoots pressing fire button very fast.
User avatar
Feb 7, 2020, 09:46
edited on: Feb 10, 2020, 15:29
Another video.

I hear music slowdown around 8:55 and 12:31. It may happen when you use "iron-whip" weapon with "fast" shoot.