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ID Category [?] Severity [?] Reproducibility Date Submitted Last Update
08013 Gameplay Minor Always Jun 23, 2021, 10:14 Jun 27, 2021, 13:31
Tester alphabeta2 View Status Public Platform MAME (Official Binary)
Assigned To Resolution Open OS Windows 10 (64-bit)
Status [?] Acknowledged Driver
Version 0.232 Fixed in Version Build 64-bit
Fixed in Git Commit Github Pull Request #
Summary 08013: jpark: [possible] Wrong knock down animation order for Second T-Rex Boss.
Description After you successfully shoot the T-Rex for first time, the T-Rex supposed to be fell down and then get back up first. By the time you managed to shoot the T-Rex for fourth time, the T-Rex will knock down and bounces. In MAME, this animation played in wrong order.


Steps To Reproduce Play through the game until you nearly reached the end of Area 2.
Additional Information
Github Commit
Flags Possible
Regression Version
Affected Sets / Systems jpark
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Senior Tester
Jun 23, 2021, 22:48
are you sure there isn't something random / context sensitive with this, as this is pure game logic, and the game isn't protected or anything, so it seems a bit unlikely.
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Jun 24, 2021, 18:34
edited on: Jun 24, 2021, 18:35
I can confirm this is a random occurrence from this vid:

From what I'm seeing, Mame always plays the "bounce" animation but never the animation where it knocks down and gets back up. On actual hardware, it will play one or the other at random. I'm suspecting a CPU core bug in that case.
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Senior Tester
Jun 24, 2021, 22:43
edited on: Jun 24, 2021, 22:44
System32 does have a hardware random number generator, it might be worth seeing if it's reading from it.

Of course they could have tied it to something really obscure, like the cabinet movement, which isn't emulated..