Viewing Issue Advanced Details Jump to Notes ] kchamp.cpp
ID Category [?] Severity [?] Reproducibility Date Submitted Last Update
06479 Sound Minor Always 27 days ago 27 days ago
Tester Tafoid View Status Public Platform MAME (Official Binary)
Assigned To AJR Resolution Open OS Windows Vista/7/8 (64-bit)
Status [?] Assigned   Driver kchamp.cpp
Version 0.182 Fixed in Version Build 64-bit
Summary 06479: kchampvs, kchampvs2, karatevs: ADPCM samples are distorted
Description There was change in source to add a "74LS157 Quad 2-to-1 Multiplexer" to accurately reflect sound but the new implementation has distortion/muffling of the samples
Steps To Reproduce
Additional Information Change here caused the issue:
https://github.com/mamedev/mame/pull/1951

Sound from original coinop linked there for comparison

Flags
Regression Version 0.182
Affected Sets / Systems kchampvs, kchampvs2, karatevs
Attached Files
 


-  Notes
User avatar
No.13563
AJR
(Developer)
27 days ago
I've been able to fix this experimentally by improving the accuracy of VCK output. However, this will break a lot of other drivers that don't check the VCK state. The old implementation always outputs 1 on what is supposed to be the active low state, even though it's far more common for VCK to be directly hooked up to the clock input of a 7474 (as the kchampvs schematics indicate), which triggers on rising edge.