mirror of
https://github.com/deater/dos33fsprogs.git
synced 2024-11-20 03:35:24 +00:00
383 lines
8.6 KiB
ArmAsm
383 lines
8.6 KiB
ArmAsm
; Mockingboad programming:
|
|
; + Has two 6522 I/O chips connected to two AY-3-8910 chips
|
|
; + Optionally has some speech chips controlled via the outport on the AY
|
|
; + Often in slot 4
|
|
; TODO: how to auto-detect?
|
|
; References used:
|
|
; http://macgui.com/usenet/?group=2&id=8366
|
|
; 6522 Data Sheet
|
|
; AY-3-8910 Data Sheet
|
|
|
|
;========================
|
|
; Mockingboard card
|
|
; Essentially two 6522s hooked to the Apple II bus
|
|
; Connected to AY-3-8910 chips
|
|
; PA0-PA7 on 6522 connected to DA0-DA7 on AY
|
|
; PB0 on 6522 connected to BC1
|
|
; PB1 on 6522 connected to BDIR
|
|
; PB2 on 6522 connected to RESET
|
|
|
|
|
|
; left speaker
|
|
MOCK_6522_ORB1 = $C400 ; 6522 #1 port b data
|
|
MOCK_6522_ORA1 = $C401 ; 6522 #1 port a data
|
|
MOCK_6522_DDRB1 = $C402 ; 6522 #1 data direction port B
|
|
MOCK_6522_DDRA1 = $C403 ; 6522 #1 data direction port A
|
|
|
|
; right speaker
|
|
MOCK_6522_ORB2 = $C480 ; 6522 #2 port b data
|
|
MOCK_6522_ORA2 = $C481 ; 6522 #2 port a data
|
|
MOCK_6522_DDRB2 = $C482 ; 6522 #2 data direction port B
|
|
MOCK_6522_DDRA2 = $C483 ; 6522 #2 data direction port A
|
|
|
|
; 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 output (1)
|
|
sta MOCK_6522_DDRB1
|
|
sta MOCK_6522_DDRA1
|
|
sta MOCK_6522_DDRB2
|
|
sta MOCK_6522_DDRA2
|
|
rts
|
|
|
|
;======================
|
|
; Reset Left AY-3-8910
|
|
;======================
|
|
reset_ay_both:
|
|
lda #MOCK_AY_RESET
|
|
sta MOCK_6522_ORB1
|
|
lda #MOCK_AY_INACTIVE
|
|
sta MOCK_6522_ORB1
|
|
|
|
;======================
|
|
; Reset Right AY-3-8910
|
|
;======================
|
|
;reset_ay_right:
|
|
;could be merged with both
|
|
lda #MOCK_AY_RESET
|
|
sta MOCK_6522_ORB2
|
|
lda #MOCK_AY_INACTIVE
|
|
sta MOCK_6522_ORB2
|
|
rts
|
|
|
|
|
|
; Write sequence
|
|
; Inactive -> Latch Address -> Inactive -> Write Data -> Inactive
|
|
|
|
;=========================================
|
|
; Write Right/Left to save value AY-3-8910
|
|
;=========================================
|
|
; register in X
|
|
; value in MB_VALUE
|
|
|
|
write_ay_both:
|
|
; address
|
|
stx MOCK_6522_ORA1 ; put address on PA1 ; 3
|
|
stx MOCK_6522_ORA2 ; put address on PA2 ; 3
|
|
lda #MOCK_AY_LATCH_ADDR ; latch_address on PB1 ; 2
|
|
sta MOCK_6522_ORB1 ; latch_address on PB1 ; 3
|
|
sta MOCK_6522_ORB2 ; latch_address on PB2 ; 3
|
|
ldy #MOCK_AY_INACTIVE ; go inactive ; 2
|
|
sty MOCK_6522_ORB1 ; 3
|
|
sty MOCK_6522_ORB2 ; 3
|
|
|
|
; value
|
|
lda MB_VALUE ; 3
|
|
sta MOCK_6522_ORA1 ; put value on PA1 ; 3
|
|
sta MOCK_6522_ORA2 ; put value on PA2 ; 3
|
|
lda #MOCK_AY_WRITE ; ; 2
|
|
sta MOCK_6522_ORB1 ; write on PB1 ; 3
|
|
sta MOCK_6522_ORB2 ; write on PB2 ; 3
|
|
sty MOCK_6522_ORB1 ; 3
|
|
sty MOCK_6522_ORB2 ; 3
|
|
|
|
rts ; 6
|
|
;===========
|
|
; 51
|
|
;=======================================
|
|
; clear ay -- clear all 14 AY registers
|
|
; should silence the card
|
|
;=======================================
|
|
clear_ay_both:
|
|
ldx #14
|
|
lda #0
|
|
sta MB_VALUE
|
|
clear_ay_left_loop:
|
|
jsr write_ay_both
|
|
dex
|
|
bpl clear_ay_left_loop
|
|
rts
|
|
|
|
;=======================================
|
|
; Detect a Mockingboard card
|
|
;=======================================
|
|
; Based on code from the French Touch "Pure Noise" Demo
|
|
; Attempts to time an instruction sequence with a 6522
|
|
;
|
|
; If found, puts in bMB
|
|
; MB_ADDRL:MB_ADDRH has address of Mockingboard
|
|
; returns X=0 if not found, X=1 if found
|
|
|
|
mockingboard_detect:
|
|
lda #0
|
|
sta MB_ADDRL
|
|
|
|
mb_detect_loop: ; self-modifying
|
|
lda #$07 ; we start in slot 7 ($C7) and go down to 0 ($C0)
|
|
ora #$C0 ; make it start with C
|
|
sta MB_ADDRH
|
|
ldy #04 ; $CX04
|
|
ldx #02 ; 2 tries?
|
|
mb_check_cycle_loop:
|
|
lda (MB_ADDRL),Y ; timer 6522 (Low Order Counter)
|
|
; count down
|
|
sta PT3_TEMP ; 3 cycles
|
|
lda (MB_ADDRL),Y ; + 5 cycles = 8 cycles
|
|
; between the two accesses to the timer
|
|
sec
|
|
sbc PT3_TEMP ; subtract to see if we had 8 cycles
|
|
cmp #$f8 ; -8
|
|
bne mb_not_in_this_slot
|
|
dex ; decrement, try one more time
|
|
bne mb_check_cycle_loop ; loop detection
|
|
inx ; Mockingboard found (X=1)
|
|
done_mb_detect:
|
|
;stx bMB ; store result to bMB
|
|
rts ; return
|
|
|
|
mb_not_in_this_slot:
|
|
dec mb_detect_loop+1 ; decrement the "slot" (self_modify)
|
|
bne mb_detect_loop ; loop down to one
|
|
ldx #00
|
|
beq done_mb_detect
|
|
|
|
;alternative MB detection from Nox Archaist
|
|
; lda #$04
|
|
; sta MB_ADDRL
|
|
; ldx #$c7
|
|
;
|
|
;find_mb:
|
|
; stx MB_ADDRH
|
|
;
|
|
; ;detect sound I
|
|
;
|
|
; sec
|
|
; ldy #$00
|
|
; lda (MB_ADDRL), y
|
|
; sbc (MB_ADDRL), y
|
|
; cmp #$05
|
|
; beq found_mb
|
|
; dex
|
|
; cpx #$c0
|
|
; bne find_mb
|
|
; ldx #$00 ;no mockingboard found
|
|
; rts
|
|
;
|
|
;found_mb:
|
|
; ldx #$01 ;mockingboard found
|
|
; rts
|
|
;
|
|
; ;optionally detect sound II
|
|
;
|
|
; sec
|
|
; ldy #$80
|
|
; lda (MB_ADDRL), y
|
|
; sbc (MB_ADDRL), y
|
|
; cmp #$05
|
|
; beq found_mb
|
|
|
|
|
|
;=======================================
|
|
; 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 ; $CX04
|
|
ldx #02 ; 2 tries?
|
|
mb4_check_cycle_loop:
|
|
lda (MB_ADDRL),Y ; timer 6522 (Low Order Counter)
|
|
; count down
|
|
sta PT3_TEMP ; 3 cycles
|
|
lda (MB_ADDRL),Y ; + 5 cycles = 8 cycles
|
|
; between the two accesses to the timer
|
|
sec
|
|
sbc PT3_TEMP ; subtract to see if we had 8 cycles
|
|
cmp #$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
|
|
|
|
.if 0
|
|
;=============================
|
|
; Setup
|
|
;=============================
|
|
pt3_setup_interrupt:
|
|
|
|
;===========================
|
|
; Check for Apple IIc
|
|
;===========================
|
|
; it does interrupts differently
|
|
|
|
lda $FBB3 ; IIe and newer is $06
|
|
cmp #6
|
|
beq apple_iie_or_newer
|
|
|
|
jmp done_apple_detect
|
|
apple_iie_or_newer:
|
|
lda $FBC0 ; 0 on a IIc
|
|
bne done_apple_detect
|
|
apple_iic:
|
|
; activate IIc mockingboard?
|
|
; this might only be necessary to allow detection
|
|
; I get the impression the Mockingboard 4c activates
|
|
; when you access any of the 6522 ports in Slot 4
|
|
lda #$ff
|
|
sta $C403
|
|
sta $C404
|
|
|
|
; bypass the firmware interrupt handler
|
|
; should we do this on IIe too? probably faster
|
|
|
|
sei ; disable interrupts
|
|
lda $c08b ; disable ROM (enable language card)
|
|
lda $c08b
|
|
lda #<interrupt_handler
|
|
sta $fffe
|
|
lda #>interrupt_handler
|
|
sta $ffff
|
|
|
|
lda #$EA ; nop out the "lda $45" in the irq hand
|
|
sta interrupt_smc
|
|
sta interrupt_smc+1
|
|
|
|
done_apple_detect:
|
|
|
|
|
|
;=========================
|
|
; Setup Interrupt Handler
|
|
;=========================
|
|
; Vector address goes to 0x3fe/0x3ff
|
|
; FIXME: should chain any existing handler
|
|
|
|
lda #<interrupt_handler
|
|
sta $03fe
|
|
lda #>interrupt_handler
|
|
sta $03ff
|
|
|
|
;============================
|
|
; Enable 50Hz clock on 6522
|
|
;============================
|
|
|
|
sei ; disable interrupts just in case
|
|
|
|
lda #$40 ; Continuous interrupts, don't touch PB7
|
|
sta $C40B ; ACR register
|
|
lda #$7F ; clear all interrupt flags
|
|
sta $C40E ; IER register (interrupt enable)
|
|
|
|
lda #$C0
|
|
sta $C40D ; IFR: 1100, enable interrupt on timer one oflow
|
|
sta $C40E ; IER: 1100, enable timer one interrupt
|
|
|
|
lda #$E7
|
|
sta $C404 ; write into low-order latch
|
|
lda #$4f
|
|
sta $C405 ; write into high-order latch,
|
|
; load both values into counter
|
|
; clear interrupt and start counting
|
|
|
|
; 4fe7 / 1e6 = .020s, 50Hz
|
|
|
|
rts
|
|
.endif
|
|
|
|
|
|
;==================================
|
|
; Print mockingboard detect message
|
|
;==================================
|
|
; note: on IIc must do this before enabling interrupt
|
|
; as we disable ROM (COUT won't work?)
|
|
|
|
print_mockingboard_detect:
|
|
|
|
; print detection message
|
|
ldy #0
|
|
print_mocking_message:
|
|
lda mocking_message,Y ; load loading message
|
|
beq done_mocking_message
|
|
ora #$80
|
|
jsr COUT
|
|
iny
|
|
jmp print_mocking_message
|
|
done_mocking_message:
|
|
jsr CROUT1
|
|
|
|
rts
|
|
|
|
print_mocking_notfound:
|
|
|
|
ldy #0
|
|
print_not_message:
|
|
lda not_message,Y ; load loading message
|
|
beq print_not_message_done
|
|
ora #$80
|
|
jsr COUT
|
|
iny
|
|
jmp print_not_message
|
|
print_not_message_done:
|
|
rts
|
|
|
|
print_mocking_found:
|
|
ldy #0
|
|
print_found_message:
|
|
lda found_message,Y ; load loading message
|
|
beq done_found_message
|
|
ora #$80
|
|
jsr COUT
|
|
iny
|
|
jmp print_found_message
|
|
done_found_message:
|
|
|
|
rts
|
|
|
|
;=========
|
|
; strings
|
|
;=========
|
|
mocking_message: .asciiz "LOOKING FOR MOCKINGBOARD IN SLOT #4"
|
|
not_message: .byte "NOT "
|
|
found_message: .asciiz "FOUND"
|
|
|
|
|