07734: tacscan: Sega Gremlin Vector game Tac-Scan Playback almost 1/2 the normal game speed on the 3D 2nd level.

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
07734	Gameplay	Minor	Always	Aug 30, 2020, 03:48	Sep 13, 2020, 01:06

Tester	vidpro1	View Status	Public	Platform	MAME (Official Binary)
Assigned To		Resolution	Open	OS	Windows 10 (64-bit)
Status [?]	Acknowledged			Driver	sega/segag80v.cpp
Version	0.224	Fixed in Version		Build	64-bit
		Fixed in Git Commit		Github Pull Request #

Summary	07734: tacscan: Sega Gremlin Vector game Tac-Scan Playback almost 1/2 the normal game speed on the 3D 2nd level.
Description	As of MAME 0.224 there is a new Universal Sound Board fix. Not sure if this has anything to do with the Tac-Scan game speed being almost half the speed on the 2nd level. All other game levels are ok. I don't see the frame FPS counter dropping either,.
Steps To Reproduce	Just play to the second 3D level and you will notice the slow down. After the second level the game speeds back up to normal speed.
Additional Information
Github Commit

Flags
Regression Version
Affected Sets / Systems	tacscan

Attached Files

No.17920 Tafoid Administrator Aug 30, 2020, 04:45	I did notice several games using the Universal Sound Board and the fixes therein in testing, many games show changed speeds from before. When I inquired about it possibly being some sort of regression I was informed that it was due to implementation of wait states to z80 memory accesses. Now, if you can find authentic recording from actual PCB to verify that indeed the change in render or speed of presentation isn't correct, that would be something we can work with. In at least one sample game checked, Astro Blaster, it was observed the new presentation is much closer to what is shown in video. &feature=youtu.be&t=1086
No.17923 vidpro1 Developer Aug 30, 2020, 10:53
No.17924 vidpro1 Developer Aug 30, 2020, 10:54	This video shows the speed perfectly.
No.17925 vidpro1 Developer Aug 30, 2020, 11:15 edited on: Aug 30, 2020, 11:16	Astro Blaster right now is playing very slow because of the netlist sound system and will have to wait on that one as the sound system eats a lot of cpu cycles. I'm very happy that it was done and will be perfect some day. That game does not use the Universal Sound Board.
No.17927 Tafoid Administrator Aug 30, 2020, 11:48	I was told it did - perhaps it is a device BASED on the implementation.
No.17973 vidpro1 Developer Sep 13, 2020, 01:06	If you use the -cheat options and overclock the Main CPU Z80 to 150% level 2 becomes ok like the original pcb. The overclock doesn't affect the other levels. Obviously not the correct fix.