Viewing Issue Advanced Details
|ID||Category [?]||Severity [?]||Reproducibility||Date Submitted||Last Update|
|06769||Core||Major||Always||Nov 21, 2017, 16:08||Nov 22, 2017, 17:37|
|Tester||demotester||View Status||Public||Platform||MAME (Official Binary)|
|Version||0.191||Fixed in Version||Build||32-bit|
|Summary||06769: bbcm: BCD test failed on 65SC02|
B-Em forum -> http://www.stardot.org.uk/forums/viewtopic.php?f=4&t=10823&start=240#p166332
The latest branch of B-Em WinBuild -> http://www.stardot.org.uk/forums/download/file.php?id=28847
The latest branch of B-Em has fixed 65SC02 BCD -> so BBC Master emu passes 65SC02 BCD test in "6502test.ssd"!
Note: "6502test.ssd" find inside the disc folder!
|Steps To Reproduce||
How to run "6502test.ssd" on MAME bbcm driver: Mount the disc on bbcm driver and press SHIFT+F12 keys!
When run the "6502test.ssd" in MAME bbcm driver, the CPU is detected as 65C02 instead of 65SC02?
Also, the Basic BCD test with 6502 and 65C02 passes but fails with 65SC02!
According to this, the BBC Master driver in MAME seems does not using 65SC02 CPU! (as other emus do)
In MAME bbcm driver "Machine Information" it says: 65SC02 2MHz!
|Affected Sets / Systems||bbcm|
mame_bbcm_6502test.png (6,400 bytes) Nov 21, 2017, 18:35 Uploaded by demotester
MAME bbcm test detection!
|There are no relationship linked to this issue.|
Nov 22, 2017, 17:37
I don't know why autodetection goes wrong.
But the reason the BCD test fails on 65C02 is because ADC/SBC decimal mode is slightly different on CMOS CPUs. MAME doesn't emulate this difference.
I didn't look into it further (don't know the exact differences)