AY test "TestAYReadHiZ"
Prior to mb-audit 1.50, I was modelling the Mockingboard (not Phasor) behaviour on my ReactiveMicro MB-C hardware which contains WDC W6522S's (not W6522N's) - specifically WDC W65C22S6TPG-14. This has a subtle difference from the R6522 (used on original MB, Phasor and ReactiveMicro cards): input lines pulled high when AY is INACTIVE vs leave last value on the bus.
This is now fixed in mb-audit 1.50, and will check for the R6522 behaviour (and emit a warning on WDC behaviour).
Errors I get from my RM MB-C:
- 21 14 00 FF 0D - Expect FF, Actual 0D
- 13 F1 08 FF C4 - Expect FF, Actual C4 (Reset test: reading IRB)
Reference: https://www.westerndesigncenter.com/wdc/documentation/w65c22.pdf
Page 50, section 5.3, Bus Holding Pins:
"All W65C22S pins except PHI2 have bus holding devices. The original NMOS 6522, W65C22N, G65SC22, and R65NC22 did not have bus holding devices."
AY test "TestAYReadHiZ"
Prior to
mb-audit 1.50, I was modelling the Mockingboard (not Phasor) behaviour on my ReactiveMicro MB-C hardware which contains WDC W6522S's (not W6522N's) - specifically WDC W65C22S6TPG-14. This has a subtle difference from the R6522 (used on original MB, Phasor and ReactiveMicro cards): input lines pulled high when AY is INACTIVE vs leave last value on the bus.This is now fixed in
mb-audit 1.50, and will check for the R6522 behaviour (and emit a warning on WDC behaviour).Errors I get from my RM MB-C:
Reference: https://www.westerndesigncenter.com/wdc/documentation/w65c22.pdf
Page 50, section 5.3, Bus Holding Pins: