00218: splndrbt: PCB sound info.

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
00218	Original Reference	Minor	Have not tried	Jan 27, 2008, 03:59	Aug 18, 2009, 07:37

Tester	Kold666	View Status	Public	Platform
Assigned To		Resolution	Open	OS
Status [?]	Confirmed			Driver	alpha/equites.cpp
Version	0.103u2	Fixed in Version		Build
		Fixed in Git Commit		Github Pull Request #

Summary	00218: splndrbt: PCB sound info.
Description	All the Alpha Denshi pcbs of early 80s use the SAME sound board marked: "SOUND BOARD NO.59 MC 07" with different EPROMS but the same PROM (so mame it's right in loading the same prom). You can infact swap the sound boards between the games providing the right eproms. The are 3 independent potentiometers for Music, sound effects and frequency. The frequency one varies the music tempo of the MSM5232. Currently mame uses it to the max frequency. I noticed that the sound emulation is not right, it misses the drummming. it is done by the AY8910 and it's a sort of a filtered white noise. If I put out from the board the Ay8910 I get a continuous white noise. So I am resonably sure the MSM5232 triggers the AY8910 to do the white noise. Infact the drumming is also in sync when you raise the frequency, and this potentiometer is only attached to the MSM5232. If you put out the MSM5232 you get no drumming or synth. On the sound board there is also an 8155 (I/O chip) which triggers the commands to do sfx and music, I don't know if this needs to be emulated. I have repaired a sound board replacing an MSM5232. It triggered the drums but no synth!
Steps To Reproduce
Additional Information
Github Commit

Flags
Regression Version
Affected Sets / Systems	splndrbt

Attached Files

No.04830 Kold666 Developer Aug 18, 2009, 07:37	I copy and paste these links in reference to how the equites.c games should sound: Alpha Denshi 5232 Special Part 2: http://nicosound.anyap.info/sound/sm6730817 Alpha Denshi 5232 Fixed: http://nicosound.anyap.info/sound/sm6516668 http://nicosound.anyap.info/sound/sm4987019 I have to say I don't know from which game they recorded the music of the first 2 links.... These are the schematics drawn by Nicola Salmoria by hand after I had desoldered the entire sound board: http://arcarc.xmission.com/PDF_Arcade_Manuals_and_Schematics/Alpha%20Denshi-sound%20board.pdf in case someone very good at discrete emulation want to have a look at.... ;)

No.04830

Kold666

Developer

Aug 18, 2009, 07:37

I copy and paste these links in reference to how the equites.c games should sound:
Alpha Denshi 5232 Special Part 2: http://nicosound.anyap.info/sound/sm6730817
Alpha Denshi 5232 Fixed: http://nicosound.anyap.info/sound/sm6516668
http://nicosound.anyap.info/sound/sm4987019

I have to say I don't know from which game they recorded the music of the first 2 links....

These are the schematics drawn by Nicola Salmoria by hand after I had desoldered the entire sound board:
http://arcarc.xmission.com/PDF_Arcade_Manuals_and_Schematics/Alpha%20Denshi-sound%20board.pdf

in case someone very good at discrete emulation want to have a look at.... ;)