mirror of
https://github.com/deater/dos33fsprogs.git
synced 2024-11-01 01:06:33 +00:00
189 lines
5.0 KiB
ArmAsm
189 lines
5.0 KiB
ArmAsm
; ZP addresses
|
|
|
|
; left channel
|
|
MOCK_6522_1_ORB = $C400 ; 6522 #1 port b data
|
|
MOCK_6522_1_ORA = $C401 ; 6522 #1 port a data
|
|
MOCK_6522_1_DDRB = $C402 ; 6522 #1 data direction port B
|
|
MOCK_6522_1_DDRA = $C403 ; 6522 #1 data direction port A
|
|
MOCK_6522_1_T1C_L = $C404 ; 6522 #1 Low-order counter
|
|
MOCK_6522_1_T1C_H = $C405 ; 6522 #1 High-order counter
|
|
MOCK_6522_1_T1L_L = $C406 ; 6522 #1 Low-order latch
|
|
MOCK_6522_1_T1L_H = $C407 ; 6522 #1 High-order latch
|
|
MOCK_6522_1_T2C_L = $C408 ; 6522 #1 Timer2 Low-order Latch/Counter
|
|
MOCK_6522_1_T2C_H = $C409 ; 6522 #1 Timer2 High-order Latch/Counter
|
|
MOCK_6522_1_SR = $C40A ; 6522 #1 Shift Register
|
|
MOCK_6522_1_ACR = $C40B ; 6522 #1 Auxiliary Control Register
|
|
MOCK_6522_1_PCR = $C40C ; 6522 #1 Peripheral Control Register
|
|
MOCK_6522_1_IFR = $C40D ; 6522 #1 Interrupt Flag Register
|
|
MOCK_6522_1_IER = $C40E ; 6522 #1 Interrupt Enable Register
|
|
MOCK_6522_1_ORAN = $C40F ; 6522 #1 port a data, no handshake
|
|
|
|
; right channel
|
|
MOCK_6522_2_ORB = $C480 ; 6522 #2 port b data
|
|
MOCK_6522_2_ORA = $C481 ; 6522 #2 port a data
|
|
MOCK_6522_2_DDRB = $C482 ; 6522 #2 data direction port B
|
|
MOCK_6522_2_DDRA = $C483 ; 6522 #2 data direction port A
|
|
MOCK_6522_2_T1C_L = $C484 ; 6522 #2 Low-order counter
|
|
MOCK_6522_2_T1C_H = $C485 ; 6522 #2 High-order counter
|
|
MOCK_6522_2_T1L_L = $C486 ; 6522 #2 Low-order latch
|
|
MOCK_6522_2_T1L_H = $C487 ; 6522 #2 High-order latch
|
|
MOCK_6522_2_T2C_L = $C488 ; 6522 #2 Timer2 Low-order Latch/Counter
|
|
MOCK_6522_2_T2C_H = $C489 ; 6522 #2 Timer2 High-order Latch/Counter
|
|
MOCK_6522_2_SR = $C48A ; 6522 #2 Shift Register
|
|
MOCK_6522_2_ACR = $C48B ; 6522 #2 Auxiliary Control Register
|
|
MOCK_6522_2_PCR = $C48C ; 6522 #2 Peripheral Control Register
|
|
MOCK_6522_2_IFR = $C48D ; 6522 #2 Interrupt Flag Register
|
|
MOCK_6522_2_IER = $C48E ; 6522 #2 Interrupt Enable Register
|
|
MOCK_6522_2_ORAN = $C48F ; 6522 #2 port a data, no handshake
|
|
|
|
|
|
; AY-3-8910 commands on port B
|
|
; RESET BDIR BC1
|
|
MOCK_AY_RESET = $0 ; 0 0 0
|
|
MOCK_AY_INACTIVE = $4 ; 1 0 0
|
|
MOCK_AY_READ = $5 ; 1 0 1
|
|
MOCK_AY_WRITE = $6 ; 1 1 0
|
|
MOCK_AY_LATCH_ADDR = $7 ; 1 1 1
|
|
|
|
|
|
;========================
|
|
; Mockingboard Init
|
|
;========================
|
|
; Initialize the 6522s
|
|
; set the data direction for all pins of PortA/PortB to be output
|
|
|
|
mockingboard_init:
|
|
lda #$ff ; all 8 pins output (1), portA
|
|
|
|
sta MOCK_6522_1_DDRA
|
|
sta MOCK_6522_2_DDRA
|
|
; only 3 pins output (1), port B
|
|
lda #$7
|
|
sta MOCK_6522_1_DDRB
|
|
|
|
sta MOCK_6522_2_DDRB
|
|
|
|
|
|
reset_ay_both:
|
|
;======================
|
|
; Reset Left AY-3-8910
|
|
;======================
|
|
reset_ay_left:
|
|
lda #MOCK_AY_RESET
|
|
sta MOCK_6522_1_ORB
|
|
lda #MOCK_AY_INACTIVE
|
|
sta MOCK_6522_1_ORB
|
|
|
|
; AY-3-8913: Wait 5 us
|
|
nop
|
|
nop
|
|
nop
|
|
nop
|
|
nop
|
|
|
|
;======================
|
|
; Reset Right AY-3-8910
|
|
;======================
|
|
reset_ay_right:
|
|
lda #MOCK_AY_RESET
|
|
sta MOCK_6522_2_ORB
|
|
lda #MOCK_AY_INACTIVE
|
|
sta MOCK_6522_2_ORB
|
|
|
|
; AY-3-8913: Wait 5 us
|
|
nop
|
|
nop
|
|
nop
|
|
nop
|
|
nop
|
|
|
|
;=========================
|
|
; Setup initial conditions
|
|
;=========================
|
|
|
|
|
|
; 7: ENABLE
|
|
ldx #7
|
|
lda #$38 ; noise disabled, ABC enabled
|
|
sta MB_VALUE
|
|
jsr write_ay_both
|
|
|
|
rts
|
|
|
|
|
|
|
|
;=========================================
|
|
; Write Right/Left to save value AY-3-8910
|
|
;=========================================
|
|
; register in X
|
|
; value in MB_VALUE
|
|
|
|
write_ay_both:
|
|
; address
|
|
stx MOCK_6522_1_ORA ; put address on PA1 ; 4
|
|
stx MOCK_6522_2_ORA ; put address on PA2 ; 4
|
|
lda #MOCK_AY_LATCH_ADDR ; latch_address on PB1 ; 2
|
|
sta MOCK_6522_1_ORB ; latch_address on PB1 ; 4
|
|
sta MOCK_6522_2_ORB ; latch_address on PB2 ; 4
|
|
lda #MOCK_AY_INACTIVE ; go inactive ; 2
|
|
sta MOCK_6522_1_ORB ; 4
|
|
sta MOCK_6522_2_ORB ; 4
|
|
;===========
|
|
; 28
|
|
; value
|
|
lda MB_VALUE ; 3
|
|
sta MOCK_6522_1_ORA ; put value on PA1 ; 4
|
|
sta MOCK_6522_2_ORA ; put value on PA2 ; 4
|
|
lda #MOCK_AY_WRITE ; ; 2
|
|
sta MOCK_6522_1_ORB ; write on PB1 ; 4
|
|
sta MOCK_6522_2_ORB ; write on PB2 ; 4
|
|
lda #MOCK_AY_INACTIVE ; go inactive ; 2
|
|
sta MOCK_6522_1_ORB ; 4
|
|
sta MOCK_6522_2_ORB ; 4
|
|
;===========
|
|
; 31
|
|
|
|
rts ; 6
|
|
;===========
|
|
; 65
|
|
|
|
;=======================================
|
|
; Detect a Mockingboard card in Slot4
|
|
;=======================================
|
|
; Based on code from the French Touch "Pure Noise" Demo
|
|
; Attempts to time an instruction sequence with a 6522
|
|
;
|
|
; MB_ADDRL:MB_ADDRH has address of Mockingboard
|
|
; returns X=0 if not found, X=1 if found
|
|
|
|
mockingboard_detect_slot4:
|
|
lda #0
|
|
sta MB_ADDRL
|
|
|
|
mb4_detect_loop: ; self-modifying
|
|
lda #$04 ; we're only looking in Slot 4
|
|
ora #$C0 ; make it start with C
|
|
sta MB_ADDRH
|
|
ldy #04 ; $CX04
|
|
ldx #02 ; 2 tries?
|
|
mb4_check_cycle_loop:
|
|
lda (MB_ADDRL),Y ; timer 6522 (Low Order Counter)
|
|
; count down
|
|
sta TEMP ; 3 cycles
|
|
lda (MB_ADDRL),Y ; + 5 cycles = 8 cycles
|
|
; between the two accesses to the timer
|
|
sec
|
|
sbc TEMP ; subtract to see if we had 8 cycles
|
|
cmp #$f8 ; -8
|
|
bne mb4_not_in_this_slot
|
|
dex ; decrement, try one more time
|
|
bne mb4_check_cycle_loop ; loop detection
|
|
inx ; Mockingboard found (X=1)
|
|
done_mb4_detect:
|
|
rts ; return
|
|
|
|
mb4_not_in_this_slot:
|
|
ldx #00
|
|
beq done_mb4_detect
|
|
|