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ID Category [?] Severity [?] Reproducibility Date Submitted Last Update
04567 Sound Trivial Always Dec 15, 2011, 20:01 30 days ago
Tester Fujix View Status Public Platform
Assigned To Resolution Open OS
Status [?] Confirmed Driver flstory.cpp
Version 0.144u3 Fixed in Version Build
Summary 04567: flstory: MSM5232 tone duration is longer in MAME.
Description MSM5232 tones decay less than the real PCB, which result undamped sounds.
Recordings of the real PCB attached.
Steps To Reproduce
Additional Information
Flags Verified with Original
Regression Version
Affected Sets / Systems flstory
Attached Files
mp3 file icon 01.MP3 (87,387 bytes) Dec 15, 2011, 20:02 Uploaded by Fujix
PCB recording
mp3 file icon 02.MP3 (849,546 bytes) Dec 15, 2011, 20:02 Uploaded by Fujix
mp3 file icon 03.MP3 (601,487 bytes) Dec 15, 2011, 20:02 Uploaded by Fujix
mp3 file icon 04.MP3 (35,773 bytes) Dec 15, 2011, 20:02 Uploaded by Fujix
mp3 file icon 05.MP3 (17,387 bytes) Dec 15, 2011, 20:03 Uploaded by Fujix
mp3 file icon 06.MP3 (51,864 bytes) Dec 15, 2011, 20:03 Uploaded by Fujix
mp3 file icon 07.MP3 (1,361 bytes) Dec 15, 2011, 20:03 Uploaded by Fujix
mp3 file icon 08.MP3 (39,748 bytes) Dec 15, 2011, 20:03 Uploaded by Fujix
jpg file icon e434089828.3_mod.jpg (244,784 bytes) 31 days ago Uploaded by eito
eito
png file icon omote-4_mod.png (677,067 bytes) 31 days ago Uploaded by eito
eito
jpg file icon poly800_msm5232_capacitors.jpg (1,158,567 bytes) 30 days ago Uploaded by eito
KORG Poly-800
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Notes
2
User avatar
No.18078
eito
Tester
31 days ago
Hello,
I have noticed this problem also and am willing to fix it.

To fix this issue, further information of real PCB needed.
Would you please take high resolution pictures of a specific part of real PCB ?

The information required is, the capacitance of capacitors placed near the MSM5232.
Please take a look of images attached. There is 8 of same capacitors placed there.
They should have some numbers/letters on their surface that indicates the capacitance of them.
We need some images with high enough resolution of them to confirm the content of the fix.
User avatar
No.18087
eito
Tester
30 days ago
For reference, I took a picture of a KORG Poly-800 PCB which uses a MSM5232.
We can see that there are 8 of 1.0μF capacitors around the MSM5232 chip.

MSM5232 uses the capacitance of these capacitors for envelope generation.
The amount of decaying depends mainly on it.

The current implementation of MAME specifies a value 1.0μF for flstory, and there is a comment that says this value is based on a real PCB.
However, with this value, the playback doesn't match with real PCB.

Other titles that use MSM5232 in MAME 0.225 use 0.39μF or 0.65μF for this value.
The value 0.39μF is, a value indicated on datasheet of MSM5232.
I can't found the source of the value 0.65μF. A comment written on msisaac(which uses 0.65μF) says that 'the value matches the sample, but it's not verified'.
If the value 0.65μF specified for flstory, the playback sounds similar with your recordings.

If the capacitors on real PCB indicates that they have capacitance of 0.65μF(or another value), then it can be proposable to use the value for flstory.