mirror of
https://github.com/deater/dos33fsprogs.git
synced 2024-12-27 02:31:00 +00:00
mockingboard: work out a bit more how the 6522 works
This commit is contained in:
Vince Weaver
parent
be03724db6
commit
54690d0f94
@ -1850,4 +1850,5 @@ ksptheme:
|
||||
.byte $EE,$00,$3E,$01,$00,$00,$00,$38,$0B,$0B,$00,$00,$00,$FF ; 01821
|
||||
.byte $EE,$00,$3E,$01,$00,$00,$00,$38,$04,$04,$00,$00,$00,$FF ; 01822
|
||||
.byte $EE,$00,$3E,$01,$00,$00,$00,$38,$00,$00,$00,$00,$00,$FF ; 01823
|
||||
.byte $FF,$FF
|
||||
; Total size = 21888 bytes
|
||||
|
||||
@ -1,51 +1,10 @@
|
||||
; http://macgui.com/usenet/?group=2&id=8366
|
||||
|
||||
; Mockingboad programming:
|
||||
; + Has two 6522 I/O chips
|
||||
; + 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
|
||||
|
||||
; $C400 ORB1 function to perform, OUT 1
|
||||
; $C401 ORA1 data, OUT 1
|
||||
; $C402 DDRB1 data direction, OUT 1
|
||||
; $C403 DDRA1 data direction, OUT 1
|
||||
|
||||
; $C480 ORB2 function to perform, OUT 2
|
||||
; $C481 ORA2 data, OUT 2
|
||||
; $C482 DDRB2 data direction, OUT 2
|
||||
; $C483 DDRA2 data direction, OUT 2
|
||||
|
||||
; To Initialize the 6522s: Store $FF at the DDRxx addresses
|
||||
|
||||
; Your program gets access to a PSG via the 6522 by using a few basic
|
||||
; Function codes which set the PSG's I/O control lines:
|
||||
;
|
||||
; Set Inactive = $04 Set PSG Reg# = $07 Write Data = $06 Reset = $00
|
||||
;
|
||||
; To Write to a PSG register: Tell the PSG which Register you wish to access
|
||||
; (i.e. Set the "current register" #) and Write the data. This is easiest to
|
||||
; do with subroutines to handle the basic Functions.
|
||||
;
|
||||
; Example Subroutines (for Output Channel 1):
|
||||
;
|
||||
; Set Reg # 1000: A9 07 8D 00 C4 A9 04 8D 00 C4 60
|
||||
; Write Data 100B: A9 06 8D 00 C4 A9 04 8D 00 C4 60
|
||||
|
||||
; Notice that each Function sub ends by setting the PSG control lines to
|
||||
; Inactive.
|
||||
; Similarly, to do a Reset (set all PSG regs to zero) ...
|
||||
|
||||
; Reset 1016: A9 00 8D 00 C4 A9 04 8D 00 C4 60
|
||||
|
||||
; To put the value $55 in PSG Register 02 (Channel B Freq. fine) ....
|
||||
|
||||
; 1080: A9 02 put Reg# in A
|
||||
; 1082: 8D 01 C4 store A at the Data address ORA1
|
||||
; 1085: 20 00 10 JSR to Set Reg# (sets "current register" to Register
|
||||
; 2)
|
||||
; 1088: A9 55 put the value $55 in A
|
||||
; 108A: 8D 01 C4 store A at the Data address ORA1
|
||||
; 108D: 20 0B 10 JSR to Write Data ($55 goes into PSG Register 2)
|
||||
; 1090: 60 Exit from subroutine
|
||||
; TODO: how to auto-detect?
|
||||
|
||||
.include "zp.inc"
|
||||
|
||||
@ -55,7 +14,181 @@
|
||||
jsr HOME
|
||||
jsr TEXT
|
||||
|
||||
lda #0
|
||||
sta DRAW_PAGE
|
||||
sta CH
|
||||
sta CV
|
||||
lda #<mocking_message
|
||||
sta OUTL
|
||||
lda #>mocking_message
|
||||
sta OUTH
|
||||
jsr move_and_print
|
||||
|
||||
;============================
|
||||
; Init the Mockingboard
|
||||
;============================
|
||||
|
||||
jsr mockingboard_init
|
||||
jsr reset_ay_left
|
||||
jsr reset_ay_right
|
||||
|
||||
;===========================
|
||||
; load pointer to the music
|
||||
;===========================
|
||||
|
||||
lda #<ksptheme
|
||||
sta INL
|
||||
lda #>ksptheme
|
||||
sta OUTL
|
||||
|
||||
play_loop:
|
||||
|
||||
|
||||
delay_a_bit:
|
||||
|
||||
lda #86
|
||||
jsr WAIT ; delay 1/2(26+27A+5A^2) us
|
||||
; 50Hz = 20ms = 20000us
|
||||
; 40000 = 26+27A+5A^2
|
||||
; 5a^2+27a-39974 = 0
|
||||
; A = 86.75
|
||||
done_play:
|
||||
lda #0
|
||||
sta CH
|
||||
lda #2
|
||||
sta CV
|
||||
lda #<done_message
|
||||
sta OUTL
|
||||
lda #>done_message
|
||||
sta OUTH
|
||||
jsr move_and_print
|
||||
|
||||
|
||||
forever_loop:
|
||||
jmp forever_loop
|
||||
|
||||
|
||||
|
||||
; left speaker
|
||||
MOCK_6522_ORB1 EQU $C400 ; function to perform, OUT 1
|
||||
MOCK_6522_ORA1 EQU $C401 ; data, OUT 1
|
||||
MOCK_6522_DDRB1 EQU $C402 ; data direction, OUT 1
|
||||
MOCK_6522_DDRA1 EQU $C403 ; data direction, OUT 1
|
||||
|
||||
; right speaker
|
||||
MOCK_6522_ORB2 EQU $C480 ; function to perform, OUT 2
|
||||
MOCK_6522_ORA2 EQU $C481 ; data, OUT 2
|
||||
MOCK_6522_DDRB2 EQU $C482 ; data direction, OUT 2
|
||||
MOCK_6522_DDRA2 EQU $C483 ; data direction, OUT 2
|
||||
|
||||
; AY-3-8910 commands on port B
|
||||
; RESET BDIR BC1
|
||||
MOCK_AY_RESET EQU $0 ; 0 0 0
|
||||
MOCK_AY_INACTIVE EQU $4 ; 1 0 0
|
||||
MOCK_AY_READ EQU $5 ; 1 0 1
|
||||
MOCK_AY_WRITE EQU $6 ; 1 1 0
|
||||
MOCK_AY_LATCH_ADDR EQU $7 ; 1 1 1
|
||||
|
||||
|
||||
;========================
|
||||
; Mockingboard card
|
||||
; Essentially two 6522s hooked to the Apple II bus
|
||||
; Connected to AY-3-8910 chips
|
||||
; PA0-PA7 on 6522 connected to DA0-DA7 on AY
|
||||
; PB0 on 6522 connected to BC1
|
||||
; PB1 on 6522 connected to BDIR
|
||||
; PB2 on 6522 connected to RESET
|
||||
|
||||
;========================
|
||||
; Mockingboard Init
|
||||
;========================
|
||||
mockingboard_init:
|
||||
; Initialize the 6522s
|
||||
; set the data direction for all pins of PortA/PortB to be output
|
||||
lda #$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_left:
|
||||
lda #MOCK_AY_RESET
|
||||
sta MOCK_6522_ORB1
|
||||
lda #MOCK_AY_INACTIVE
|
||||
sta MOCK_6522_ORB1
|
||||
rts
|
||||
|
||||
;======================
|
||||
; Reset Right AY-3-8910
|
||||
;======================
|
||||
reset_ay_right:
|
||||
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 AY-3-8910
|
||||
;=======================
|
||||
; register in X
|
||||
; value in Y
|
||||
|
||||
write_right_ay:
|
||||
; address
|
||||
stx MOCK_6522_ORA1 ; put address on PA
|
||||
lda #MOCK_AY_LATCH_ADDR ; latch_address on PB
|
||||
sta MOCK_6522_ORB1
|
||||
lda #MOCK_AY_INACTIVE ; go inactive
|
||||
sta MOCK_6522_ORB1
|
||||
|
||||
; value
|
||||
sty MOCK_6522_ORA1 ; put value on PA
|
||||
lda #MOCK_AY_WRITE ; write on PB
|
||||
sta MOCK_6522_ORB1
|
||||
lda #MOCK_AY_INACTIVE ; go inactive
|
||||
sta MOCK_6522_ORB1
|
||||
|
||||
rts
|
||||
|
||||
;=======================
|
||||
; Write Left AY-3-8910
|
||||
;=======================
|
||||
; register in X
|
||||
; value in Y
|
||||
|
||||
write_left_ay:
|
||||
; address
|
||||
stx MOCK_6522_ORA2 ; put address on PA
|
||||
lda #MOCK_AY_LATCH_ADDR ; latch_address on PB
|
||||
sta MOCK_6522_ORB2
|
||||
lda #MOCK_AY_INACTIVE ; go inactive
|
||||
sta MOCK_6522_ORB2
|
||||
|
||||
; value
|
||||
sty MOCK_6522_ORA2 ; put value on PA
|
||||
lda #MOCK_AY_WRITE ; write on PB
|
||||
sta MOCK_6522_ORB2
|
||||
lda #MOCK_AY_INACTIVE ; go inactive
|
||||
sta MOCK_6522_ORB2
|
||||
|
||||
rts
|
||||
|
||||
|
||||
;routines
|
||||
.include "../asm_routines/gr_offsets.s"
|
||||
.include "../asm_routines/text_print.s"
|
||||
|
||||
; music
|
||||
.include "ksptheme_uncompressed.inc"
|
||||
|
||||
mocking_message: .asciiz "ASSUMING MOCKINGBOARD IN SLOT #4"
|
||||
done_message: .asciiz "DONE PLAYING"
|
||||
|
||||
Loading…
Reference in New Issue
Block a user