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Adds support for Mockingboard noise channel. WIP!

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Bobbi Webber-Manners 2022-11-27 21:55:40 -05:00
parent 6b9ab9af0f
commit 1c3d849cc3
3 changed files with 52 additions and 23 deletions
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BIN
applecorn.po
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71
mainmem.mock.s
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@ -83,12 +83,15 @@ MOCKINIT LDA #$FF ; All VIA pins output
* Silence all channels
MOCKSILENT LDX #13 ; Clear all 14 AY-3 regs
LDA #$00
:L0 JSR MOCKWRT
:L0 JSR MOCKWRT1
JSR MOCKWRT2
DEX
BPL :L0
LDA #$38 ; Turn off noise
LDX #07
JSR MOCKWRT
JSR MOCKWRT1 ; First AY-3
LDA #$14 ; A,B=tone; C=noise
JSR MOCKWRT2 ; Second AY-3
RTS
@ -122,17 +125,22 @@ MOCKNOTE PHA
* Preserves X & Y
MOCKFREQ PHX
CPX #$00 ; Noise channel
BEQ :DONE ; TODO: IGNORE NOISE FOR NOW
BEQ :NOISE
TXA
DEC A ; Subtract 1
ASL ; Double to get fine register
TAX
LDA MFREQLOW,Y ; LSB of divider
JSR MOCKWRT ; Write value to AY-3 register
JSR MOCKWRT1 ; Write value to AY-3 register
INX ; Add one for course register
LDA MFREQHIGH,Y ; MSB of divider
JSR MOCKWRT ; Write value to AY-3 register
:DONE PLX
JSR MOCKWRT1 ; Write value to AY-3 register
PLX
RTS
:NOISE LDX #6 ; Noise period register
TYA ; TODO TEMPORARY HACK
JSR MOCKWRT2 ; Write value to AY-3 register
PLX
RTS
@ -141,7 +149,7 @@ MOCKFREQ PHX
* Preserves X & Y
MOCKAMP PHX
CPX #$00 ; Noise channel
BEQ :DONE ; Has no amplitude
BEQ :NOISE
TXA ; Add 7 to get register
CLC
ADC #7
@ -151,18 +159,24 @@ MOCKAMP PHX
LSR
LSR
LSR ; Now 0..15
JSR MOCKWRT ; Write value to AY-3 register
:DONE PLX
JSR MOCKWRT1 ; Write value to AY-3 register
PLX
RTS
:NOISE LDX #10 ; Chan C
TYA ; Amplitude 0..255
LSR ; Divide by 16
LSR
LSR
LSR ; Now 0..15
JSR MOCKWRT2 ; Write value to AY-3 register
PLX
RTS
* Mockingboard interrupt service routine - just calls generic audio ISR
MOCKISR CLD
BIT MOCK_6522_IFR ; See if interrupt was from MB
BMI :MOCK ; Yes
SEC ; We did not service irc
RTS
:MOCK BIT MOCK_6522_T1CL ; Clear interrupt
* TODO: Check whether interrupt is from Mockingboard or not
BIT MOCK_6522_T1CL ; Clear interrupt
JSR AUDIOISR
CLC ; CC indicates we serviced irq
RTS
@ -172,28 +186,43 @@ MOCKISR CLD
** Private functions follow (ie: not part of driver API)
**
* Write to both AY-3s
* Write to first AY-3
* On entry: A - value, X - register
* On exit: All regs preserved.
MOCKWRT PHY
MOCKWRT1 PHY
STX MOCK_6522_ORA1 ; Latch the address
STX MOCK_6522_ORA2
LDY #MOCK_AY_LATCH_ADDR
STY MOCK_6522_ORB1
STY MOCK_6522_ORB2
LDY #MOCK_AY_INACTIVE ; Go inactive
STY MOCK_6522_ORB1
STY MOCK_6522_ORB2
STA MOCK_6522_ORA1 ; Write data
STA MOCK_6522_ORA2
LDY #MOCK_AY_WRITE
STY MOCK_6522_ORB1
STY MOCK_6522_ORB2
LDY #MOCK_AY_INACTIVE ; Go inactive
STY MOCK_6522_ORB1
PLY
RTS
* Write to second AY-3
* On entry: A - value, X - register
* On exit: All regs preserved.
MOCKWRT2 PHY
STX MOCK_6522_ORA2 ; Latch the address
LDY #MOCK_AY_LATCH_ADDR
STY MOCK_6522_ORB2
LDY #MOCK_AY_INACTIVE ; Go inactive
STY MOCK_6522_ORB2
STA MOCK_6522_ORA2 ; Write data
LDY #MOCK_AY_WRITE
STY MOCK_6522_ORB2
LDY #MOCK_AY_INACTIVE ; Go inactive
STY MOCK_6522_ORB2
PLY
RTS

4
mame_applecorn
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@ -1,2 +1,2 @@
#mame -w apple2ee -debug -sl5 mouse -sl7 cffa2 -harddisk1 ~/Personal/Development/Applecorn/applecorn.po
mame -w apple2gs -debug -sl7 cffa2 -harddisk1 ~/Personal/Development/Applecorn/applecorn.po -harddisk2 tests/JGHMusic2.po
mame -w apple2ee -debug -sl5 mouse -sl7 cffa2 -harddisk1 ~/Personal/Development/Applecorn/applecorn.po
#mame -w apple2gs -debug -sl7 cffa2 -harddisk1 ~/Personal/Development/Applecorn/applecorn.po -harddisk2 tests/JGHMusic2.po