798 lines
21 KiB
ArmAsm
798 lines
21 KiB
ArmAsm
; VMW Chiptune Player
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.include "zp.inc"
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;=============================
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; Setup
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;=============================
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;============================
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; Init the Mockingboard
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;============================
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jsr mockingboard_init
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jsr reset_ay_both
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jsr clear_ay_both
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;=========================
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; Setup Interrupt Handler
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;=========================
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; Vector address goes to 0x3fe/0x3ff
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lda #<interrupt_handler
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sta $03fe
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lda #>interrupt_handler
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sta $03ff
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;============================
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; Enable 50Hz clock on 6522
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;============================
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sei ; disable interrupts just in case
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lda #$40 ; Continuous interrupts, don't touch PB7
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sta $C40B ; ACR register
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lda #$7F ; clear all interrupt flags
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sta $C40E ; IER register (interrupt enable)
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lda #$C0
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sta $C40D ; IFR: 1100, enable interrupt on timer one oflow
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sta $C40E ; IER: 1100, enable timer one interrupt
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lda #$E7
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sta $C404 ; write into low-order latch
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lda #$4f
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sta $C405 ; write into high-order latch,
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; load both values into counter
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; clear interrupt and start counting
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; 4fe7 / 1e6 = .020s, 50Hz
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;==================
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; load first song
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;==================
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;=========================
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; Init Variables
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;=========================
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lda #$0
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sta MB_CHUNK_OFFSET
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lda #3
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sta CHUNKSIZE
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;===========================
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; Load in KRW file
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;===========================
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lda #<UNPACK_BUFFER ; set input pointer
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sta INL
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lda #>UNPACK_BUFFER
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sta INH
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;============================
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; Enable 6502 interrupts
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;============================
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cli ; clear interrupt mask
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;============================
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; Loop forever
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;============================
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main_loop:
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jmp main_loop
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;=========
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;routines
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;=========
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; left speaker
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MOCK_6522_ORB1 EQU $C400 ; 6522 #1 port b data
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MOCK_6522_ORA1 EQU $C401 ; 6522 #1 port a data
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MOCK_6522_DDRB1 EQU $C402 ; 6522 #1 data direction port B
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MOCK_6522_DDRA1 EQU $C403 ; 6522 #1 data direction port A
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; right speaker
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MOCK_6522_ORB2 EQU $C480 ; 6522 #2 port b data
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MOCK_6522_ORA2 EQU $C481 ; 6522 #2 port a data
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MOCK_6522_DDRB2 EQU $C482 ; 6522 #2 data direction port B
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MOCK_6522_DDRA2 EQU $C483 ; 6522 #2 data direction port A
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; AY-3-8910 commands on port B
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; RESET BDIR BC1
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MOCK_AY_RESET EQU $0 ; 0 0 0
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MOCK_AY_INACTIVE EQU $4 ; 1 0 0
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MOCK_AY_READ EQU $5 ; 1 0 1
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MOCK_AY_WRITE EQU $6 ; 1 1 0
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MOCK_AY_LATCH_ADDR EQU $7 ; 1 1 1
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;========================
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; Mockingboard Init
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;========================
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; Initialize the 6522s
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; set the data direction for all pins of PortA/PortB to be output
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mockingboard_init:
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lda #$ff ; all output (1)
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sta MOCK_6522_DDRB1
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sta MOCK_6522_DDRA1
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sta MOCK_6522_DDRB2
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sta MOCK_6522_DDRA2
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rts
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;======================
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; Reset Left AY-3-8910
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;======================
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reset_ay_both:
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lda #MOCK_AY_RESET
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sta MOCK_6522_ORB1
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lda #MOCK_AY_INACTIVE
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sta MOCK_6522_ORB1
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;======================
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; Reset Right AY-3-8910
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;======================
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;reset_ay_right:
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lda #MOCK_AY_RESET
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sta MOCK_6522_ORB2
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lda #MOCK_AY_INACTIVE
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sta MOCK_6522_ORB2
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rts
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; Write sequence
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; Inactive -> Latch Address -> Inactive -> Write Data -> Inactive
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;=========================================
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; Write Right/Left to save value AY-3-8910
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;=========================================
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; register in X
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; value in MB_VALUE
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write_ay_both:
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; address
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stx MOCK_6522_ORA1 ; put address on PA1 ; 3
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stx MOCK_6522_ORA2 ; put address on PA2 ; 3
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lda #MOCK_AY_LATCH_ADDR ; latch_address on PB1 ; 2
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sta MOCK_6522_ORB1 ; latch_address on PB1 ; 3
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sta MOCK_6522_ORB2 ; latch_address on PB2 ; 3
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lda #MOCK_AY_INACTIVE ; go inactive ; 2
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sta MOCK_6522_ORB1 ; 3
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sta MOCK_6522_ORB2 ; 3
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; value
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lda MB_VALUE ; 3
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sta MOCK_6522_ORA1 ; put value on PA1 ; 3
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sta MOCK_6522_ORA2 ; put value on PA2 ; 3
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lda #MOCK_AY_WRITE ; ; 2
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sta MOCK_6522_ORB1 ; write on PB1 ; 3
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sta MOCK_6522_ORB2 ; write on PB2 ; 3
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lda #MOCK_AY_INACTIVE ; go inactive ; 2
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sta MOCK_6522_ORB1 ; 3
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sta MOCK_6522_ORB2 ; 3
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rts ; 6
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;===========
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; 53
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;=======================================
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; clear ay -- clear all 14 AY registers
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; should silence the card
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;=======================================
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clear_ay_both:
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ldx #14
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lda #0
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sta MB_VALUE
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clear_ay_left_loop:
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jsr write_ay_both
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dex
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bpl clear_ay_left_loop
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rts
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;================================
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;================================
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; mockingboard interrupt handler
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;================================
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;================================
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interrupt_handler:
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pha ; save A ; 3
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; Should we save X and Y too?
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bit $C404 ; clear 6522 interrupt by reading T1C-L ; 4
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mb_play_music:
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;======================================
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; Write frames to Mockingboard
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;======================================
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; actually plays frame loaded at end of
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; last interrupt, so 20ms behind?
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mb_write_frame:
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ldx #0 ; set up reg count ; 2
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;============
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; 2
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;==================================
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; loop through the 14 registers
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; reading the value, then write out
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;==================================
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; CHANNEL A LOW
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mb_write_loop_0:
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; lda REGISTER_DUMP,X ; load register value ; 4
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; cmp REGISTER_OLD,X ; compare with old values ; 4
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; beq mb_no_write_0 ; 3/2nt
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mb_write_0:
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; address
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; stx MOCK_6522_ORA1 ; put address on PA1 ; 4
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; stx MOCK_6522_ORA2 ; put address on PA2 ; 4
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; lda #MOCK_AY_LATCH_ADDR ; latch_address for PB1 ; 2
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; sta MOCK_6522_ORB1 ; latch_address on PB1 ; 4
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; sta MOCK_6522_ORB2 ; latch_address on PB2 ; 4
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; lda #MOCK_AY_INACTIVE ; go inactive ; 2
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; sta MOCK_6522_ORB1 ; 4
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; sta MOCK_6522_ORB2 ; 4
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; value
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; lda REGISTER_DUMP,X ; load register value ; 4
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; sta MOCK_6522_ORA1 ; put value on PA1 ; 4
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; sta MOCK_6522_ORA2 ; put value on PA2 ; 4
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; lda #MOCK_AY_WRITE ; ; 2
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; sta MOCK_6522_ORB1 ; write on PB1 ; 4
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; sta MOCK_6522_ORB2 ; write on PB2 ; 4
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; lda #MOCK_AY_INACTIVE ; go inactive ; 2
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; sta MOCK_6522_ORB1 ; 4
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; sta MOCK_6522_ORB2 ; 4
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;===========
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; 62
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mb_no_write_0:
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inx ; point to next register ; 2
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; CHANNEL A HIGH
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mb_write_loop_1:
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; lda REGISTER_DUMP,X ; load register value ; 4
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; cmp REGISTER_OLD,X ; compare with old values ; 4
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; beq mb_no_write_1 ; 3/2nt
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mb_write_1:
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; address
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; stx MOCK_6522_ORA1 ; put address on PA1 ; 4
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; stx MOCK_6522_ORA2 ; put address on PA2 ; 4
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; lda #MOCK_AY_LATCH_ADDR ; latch_address for PB1 ; 2
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; sta MOCK_6522_ORB1 ; latch_address on PB1 ; 4
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; sta MOCK_6522_ORB2 ; latch_address on PB2 ; 4
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; lda #MOCK_AY_INACTIVE ; go inactive ; 2
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; sta MOCK_6522_ORB1 ; 4
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; sta MOCK_6522_ORB2 ; 4
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; value
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; lda REGISTER_DUMP,X ; load register value ; 4
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; sta MOCK_6522_ORA1 ; put value on PA1 ; 4
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; sta MOCK_6522_ORA2 ; put value on PA2 ; 4
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; lda #MOCK_AY_WRITE ; ; 2
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; sta MOCK_6522_ORB1 ; write on PB1 ; 4
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; sta MOCK_6522_ORB2 ; write on PB2 ; 4
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; lda #MOCK_AY_INACTIVE ; go inactive ; 2
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; sta MOCK_6522_ORB1 ; 4
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; sta MOCK_6522_ORB2 ; 4
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;===========
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; 62
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mb_no_write_1:
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inx ; point to next register ; 2
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; CHANNEL B LOW
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mb_write_loop_2:
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; lda REGISTER_DUMP,X ; load register value ; 4
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; cmp REGISTER_OLD,X ; compare with old values ; 4
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; beq mb_no_write_2 ; 3/2nt
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mb_write_2:
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; address
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; stx MOCK_6522_ORA1 ; put address on PA1 ; 4
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; stx MOCK_6522_ORA2 ; put address on PA2 ; 4
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; lda #MOCK_AY_LATCH_ADDR ; latch_address for PB1 ; 2
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; sta MOCK_6522_ORB1 ; latch_address on PB1 ; 4
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; sta MOCK_6522_ORB2 ; latch_address on PB2 ; 4
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; lda #MOCK_AY_INACTIVE ; go inactive ; 2
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; sta MOCK_6522_ORB1 ; 4
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; sta MOCK_6522_ORB2 ; 4
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; value
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; lda REGISTER_DUMP,X ; load register value ; 4
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; sta MOCK_6522_ORA1 ; put value on PA1 ; 4
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; sta MOCK_6522_ORA2 ; put value on PA2 ; 4
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; lda #MOCK_AY_WRITE ; ; 2
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; sta MOCK_6522_ORB1 ; write on PB1 ; 4
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; sta MOCK_6522_ORB2 ; write on PB2 ; 4
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; lda #MOCK_AY_INACTIVE ; go inactive ; 2
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; sta MOCK_6522_ORB1 ; 4
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; sta MOCK_6522_ORB2 ; 4
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;===========
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; 62
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mb_no_write_2:
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inx ; point to next register ; 2
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; CHANNEL B HIGH
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mb_write_loop_3:
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; lda REGISTER_DUMP,X ; load register value ; 4
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; cmp REGISTER_OLD,X ; compare with old values ; 4
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; beq mb_no_write_3 ; 3/2nt
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mb_write_3:
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; address
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; stx MOCK_6522_ORA1 ; put address on PA1 ; 4
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; stx MOCK_6522_ORA2 ; put address on PA2 ; 4
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; lda #MOCK_AY_LATCH_ADDR ; latch_address for PB1 ; 2
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; sta MOCK_6522_ORB1 ; latch_address on PB1 ; 4
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; sta MOCK_6522_ORB2 ; latch_address on PB2 ; 4
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; lda #MOCK_AY_INACTIVE ; go inactive ; 2
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; sta MOCK_6522_ORB1 ; 4
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; sta MOCK_6522_ORB2 ; 4
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;
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; value
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; lda REGISTER_DUMP,X ; load register value ; 4
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; sta MOCK_6522_ORA1 ; put value on PA1 ; 4
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; sta MOCK_6522_ORA2 ; put value on PA2 ; 4
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; lda #MOCK_AY_WRITE ; ; 2
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; sta MOCK_6522_ORB1 ; write on PB1 ; 4
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; sta MOCK_6522_ORB2 ; write on PB2 ; 4
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; lda #MOCK_AY_INACTIVE ; go inactive ; 2
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; sta MOCK_6522_ORB1 ; 4
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; sta MOCK_6522_ORB2 ; 4
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;===========
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; 62
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mb_no_write_3:
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inx ; point to next register ; 2
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; C CHANNEL LOW
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mb_write_loop_4:
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lda REGISTER_DUMP,X ; load register value ; 4
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cmp REGISTER_OLD,X ; compare with old values ; 4
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beq mb_no_write_4 ; 3/2nt
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mb_write_4:
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; address
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stx MOCK_6522_ORA1 ; put address on PA1 ; 4
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stx MOCK_6522_ORA2 ; put address on PA2 ; 4
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lda #MOCK_AY_LATCH_ADDR ; latch_address for PB1 ; 2
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sta MOCK_6522_ORB1 ; latch_address on PB1 ; 4
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sta MOCK_6522_ORB2 ; latch_address on PB2 ; 4
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lda #MOCK_AY_INACTIVE ; go inactive ; 2
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sta MOCK_6522_ORB1 ; 4
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sta MOCK_6522_ORB2 ; 4
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; value
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lda REGISTER_DUMP,X ; load register value ; 4
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sta MOCK_6522_ORA1 ; put value on PA1 ; 4
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sta MOCK_6522_ORA2 ; put value on PA2 ; 4
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lda #MOCK_AY_WRITE ; ; 2
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sta MOCK_6522_ORB1 ; write on PB1 ; 4
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sta MOCK_6522_ORB2 ; write on PB2 ; 4
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lda #MOCK_AY_INACTIVE ; go inactive ; 2
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sta MOCK_6522_ORB1 ; 4
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sta MOCK_6522_ORB2 ; 4
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;===========
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; 62
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mb_no_write_4:
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inx ; point to next register ; 2
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; C CHANNEL HIGH
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mb_write_loop_5:
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lda REGISTER_DUMP,X ; load register value ; 4
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cmp REGISTER_OLD,X ; compare with old values ; 4
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beq mb_no_write_5 ; 3/2nt
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mb_write_5:
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; address
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stx MOCK_6522_ORA1 ; put address on PA1 ; 4
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stx MOCK_6522_ORA2 ; put address on PA2 ; 4
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lda #MOCK_AY_LATCH_ADDR ; latch_address for PB1 ; 2
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sta MOCK_6522_ORB1 ; latch_address on PB1 ; 4
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sta MOCK_6522_ORB2 ; latch_address on PB2 ; 4
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lda #MOCK_AY_INACTIVE ; go inactive ; 2
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sta MOCK_6522_ORB1 ; 4
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sta MOCK_6522_ORB2 ; 4
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; value
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lda REGISTER_DUMP,X ; load register value ; 4
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sta MOCK_6522_ORA1 ; put value on PA1 ; 4
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sta MOCK_6522_ORA2 ; put value on PA2 ; 4
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lda #MOCK_AY_WRITE ; ; 2
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sta MOCK_6522_ORB1 ; write on PB1 ; 4
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sta MOCK_6522_ORB2 ; write on PB2 ; 4
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lda #MOCK_AY_INACTIVE ; go inactive ; 2
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sta MOCK_6522_ORB1 ; 4
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sta MOCK_6522_ORB2 ; 4
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;===========
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; 62
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mb_no_write_5:
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inx ; point to next register ; 2
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; NOISE PERIOD
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mb_write_loop_6:
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; lda REGISTER_DUMP,X ; load register value ; 4
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; cmp REGISTER_OLD,X ; compare with old values ; 4
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; beq mb_no_write_6 ; 3/2nt
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mb_write_6:
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; address
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; stx MOCK_6522_ORA1 ; put address on PA1 ; 4
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; stx MOCK_6522_ORA2 ; put address on PA2 ; 4
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; lda #MOCK_AY_LATCH_ADDR ; latch_address for PB1 ; 2
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; sta MOCK_6522_ORB1 ; latch_address on PB1 ; 4
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; sta MOCK_6522_ORB2 ; latch_address on PB2 ; 4
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; lda #MOCK_AY_INACTIVE ; go inactive ; 2
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; sta MOCK_6522_ORB1 ; 4
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; sta MOCK_6522_ORB2 ; 4
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; value
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; lda REGISTER_DUMP,X ; load register value ; 4
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; sta MOCK_6522_ORA1 ; put value on PA1 ; 4
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; sta MOCK_6522_ORA2 ; put value on PA2 ; 4
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; lda #MOCK_AY_WRITE ; ; 2
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; sta MOCK_6522_ORB1 ; write on PB1 ; 4
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; sta MOCK_6522_ORB2 ; write on PB2 ; 4
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; lda #MOCK_AY_INACTIVE ; go inactive ; 2
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; sta MOCK_6522_ORB1 ; 4
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; sta MOCK_6522_ORB2 ; 4
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;===========
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; 62
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mb_no_write_6:
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inx ; point to next register ; 2
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; ENABLE
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mb_write_loop_7:
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lda REGISTER_DUMP,X ; load register value ; 4
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cmp REGISTER_OLD,X ; compare with old values ; 4
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beq mb_no_write_7 ; 3/2nt
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mb_write_7:
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; address
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stx MOCK_6522_ORA1 ; put address on PA1 ; 4
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stx MOCK_6522_ORA2 ; put address on PA2 ; 4
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lda #MOCK_AY_LATCH_ADDR ; latch_address for PB1 ; 2
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sta MOCK_6522_ORB1 ; latch_address on PB1 ; 4
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sta MOCK_6522_ORB2 ; latch_address on PB2 ; 4
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lda #MOCK_AY_INACTIVE ; go inactive ; 2
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sta MOCK_6522_ORB1 ; 4
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sta MOCK_6522_ORB2 ; 4
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; value
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lda REGISTER_DUMP,X ; load register value ; 4
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sta MOCK_6522_ORA1 ; put value on PA1 ; 4
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sta MOCK_6522_ORA2 ; put value on PA2 ; 4
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lda #MOCK_AY_WRITE ; ; 2
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sta MOCK_6522_ORB1 ; write on PB1 ; 4
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sta MOCK_6522_ORB2 ; write on PB2 ; 4
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lda #MOCK_AY_INACTIVE ; go inactive ; 2
|
|
sta MOCK_6522_ORB1 ; 4
|
|
sta MOCK_6522_ORB2 ; 4
|
|
;===========
|
|
; 62
|
|
mb_no_write_7:
|
|
inx ; point to next register ; 2
|
|
|
|
; A amplitude
|
|
mb_write_loop_8:
|
|
; lda REGISTER_DUMP,X ; load register value ; 4
|
|
; cmp REGISTER_OLD,X ; compare with old values ; 4
|
|
; beq mb_no_write_8 ; 3/2nt
|
|
|
|
mb_write_8:
|
|
|
|
|
|
; address
|
|
; stx MOCK_6522_ORA1 ; put address on PA1 ; 4
|
|
; stx MOCK_6522_ORA2 ; put address on PA2 ; 4
|
|
; lda #MOCK_AY_LATCH_ADDR ; latch_address for PB1 ; 2
|
|
; sta MOCK_6522_ORB1 ; latch_address on PB1 ; 4
|
|
; sta MOCK_6522_ORB2 ; latch_address on PB2 ; 4
|
|
; lda #MOCK_AY_INACTIVE ; go inactive ; 2
|
|
; sta MOCK_6522_ORB1 ; 4
|
|
; sta MOCK_6522_ORB2 ; 4
|
|
|
|
; value
|
|
; lda REGISTER_DUMP,X ; load register value ; 4
|
|
; sta MOCK_6522_ORA1 ; put value on PA1 ; 4
|
|
; sta MOCK_6522_ORA2 ; put value on PA2 ; 4
|
|
; lda #MOCK_AY_WRITE ; ; 2
|
|
; sta MOCK_6522_ORB1 ; write on PB1 ; 4
|
|
; sta MOCK_6522_ORB2 ; write on PB2 ; 4
|
|
; lda #MOCK_AY_INACTIVE ; go inactive ; 2
|
|
; sta MOCK_6522_ORB1 ; 4
|
|
; sta MOCK_6522_ORB2 ; 4
|
|
;===========
|
|
; 62
|
|
mb_no_write_8:
|
|
inx ; point to next register ; 2
|
|
|
|
; B Amplitude
|
|
mb_write_loop_9:
|
|
; lda REGISTER_DUMP,X ; load register value ; 4
|
|
; cmp REGISTER_OLD,X ; compare with old values ; 4
|
|
; beq mb_no_write_9 ; 3/2nt
|
|
|
|
mb_write_9:
|
|
|
|
|
|
; address
|
|
; stx MOCK_6522_ORA1 ; put address on PA1 ; 4
|
|
; stx MOCK_6522_ORA2 ; put address on PA2 ; 4
|
|
; lda #MOCK_AY_LATCH_ADDR ; latch_address for PB1 ; 2
|
|
; sta MOCK_6522_ORB1 ; latch_address on PB1 ; 4
|
|
; sta MOCK_6522_ORB2 ; latch_address on PB2 ; 4
|
|
; lda #MOCK_AY_INACTIVE ; go inactive ; 2
|
|
; sta MOCK_6522_ORB1 ; 4
|
|
; sta MOCK_6522_ORB2 ; 4
|
|
|
|
; value
|
|
; lda REGISTER_DUMP,X ; load register value ; 4
|
|
; sta MOCK_6522_ORA1 ; put value on PA1 ; 4
|
|
; sta MOCK_6522_ORA2 ; put value on PA2 ; 4
|
|
; lda #MOCK_AY_WRITE ; ; 2
|
|
; sta MOCK_6522_ORB1 ; write on PB1 ; 4
|
|
; sta MOCK_6522_ORB2 ; write on PB2 ; 4
|
|
; lda #MOCK_AY_INACTIVE ; go inactive ; 2
|
|
; sta MOCK_6522_ORB1 ; 4
|
|
; sta MOCK_6522_ORB2 ; 4
|
|
; ;===========
|
|
; 62
|
|
mb_no_write_9:
|
|
inx ; point to next register ; 2
|
|
|
|
; C Amplitude
|
|
mb_write_loop_10:
|
|
lda REGISTER_DUMP,X ; load register value ; 4
|
|
cmp REGISTER_OLD,X ; compare with old values ; 4
|
|
beq mb_no_write_10 ; 3/2nt
|
|
|
|
mb_write_10:
|
|
|
|
|
|
; address
|
|
stx MOCK_6522_ORA1 ; put address on PA1 ; 4
|
|
stx MOCK_6522_ORA2 ; put address on PA2 ; 4
|
|
lda #MOCK_AY_LATCH_ADDR ; latch_address for PB1 ; 2
|
|
sta MOCK_6522_ORB1 ; latch_address on PB1 ; 4
|
|
sta MOCK_6522_ORB2 ; latch_address on PB2 ; 4
|
|
lda #MOCK_AY_INACTIVE ; go inactive ; 2
|
|
sta MOCK_6522_ORB1 ; 4
|
|
sta MOCK_6522_ORB2 ; 4
|
|
|
|
; value
|
|
lda REGISTER_DUMP,X ; load register value ; 4
|
|
sta MOCK_6522_ORA1 ; put value on PA1 ; 4
|
|
sta MOCK_6522_ORA2 ; put value on PA2 ; 4
|
|
lda #MOCK_AY_WRITE ; ; 2
|
|
sta MOCK_6522_ORB1 ; write on PB1 ; 4
|
|
sta MOCK_6522_ORB2 ; write on PB2 ; 4
|
|
lda #MOCK_AY_INACTIVE ; go inactive ; 2
|
|
sta MOCK_6522_ORB1 ; 4
|
|
sta MOCK_6522_ORB2 ; 4
|
|
;===========
|
|
; 62
|
|
mb_no_write_10:
|
|
inx ; point to next register ; 2
|
|
|
|
mb_write_loop_11:
|
|
; lda REGISTER_DUMP,X ; load register value ; 4
|
|
; cmp REGISTER_OLD,X ; compare with old values ; 4
|
|
; beq mb_no_write_11 ; 3/2nt
|
|
|
|
mb_write_11:
|
|
|
|
|
|
; address
|
|
; stx MOCK_6522_ORA1 ; put address on PA1 ; 4
|
|
; stx MOCK_6522_ORA2 ; put address on PA2 ; 4
|
|
; lda #MOCK_AY_LATCH_ADDR ; latch_address for PB1 ; 2
|
|
; sta MOCK_6522_ORB1 ; latch_address on PB1 ; 4
|
|
; sta MOCK_6522_ORB2 ; latch_address on PB2 ; 4
|
|
; lda #MOCK_AY_INACTIVE ; go inactive ; 2
|
|
; sta MOCK_6522_ORB1 ; 4
|
|
; sta MOCK_6522_ORB2 ; 4
|
|
;
|
|
; value
|
|
; lda REGISTER_DUMP,X ; load register value ; 4
|
|
; sta MOCK_6522_ORA1 ; put value on PA1 ; 4
|
|
; sta MOCK_6522_ORA2 ; put value on PA2 ; 4
|
|
; lda #MOCK_AY_WRITE ; ; 2
|
|
; sta MOCK_6522_ORB1 ; write on PB1 ; 4
|
|
; sta MOCK_6522_ORB2 ; write on PB2 ; 4
|
|
; lda #MOCK_AY_INACTIVE ; go inactive ; 2
|
|
; sta MOCK_6522_ORB1 ; 4
|
|
; sta MOCK_6522_ORB2 ; 4
|
|
;===========
|
|
; 62
|
|
mb_no_write_11:
|
|
inx ; point to next register ; 2
|
|
|
|
mb_write_loop_12:
|
|
; lda REGISTER_DUMP,X ; load register value ; 4
|
|
; cmp REGISTER_OLD,X ; compare with old values ; 4
|
|
; beq mb_no_write_12 ; 3/2nt
|
|
|
|
mb_write_12:
|
|
|
|
|
|
; address
|
|
; stx MOCK_6522_ORA1 ; put address on PA1 ; 4
|
|
; stx MOCK_6522_ORA2 ; put address on PA2 ; 4
|
|
; lda #MOCK_AY_LATCH_ADDR ; latch_address for PB1 ; 2
|
|
; sta MOCK_6522_ORB1 ; latch_address on PB1 ; 4
|
|
; sta MOCK_6522_ORB2 ; latch_address on PB2 ; 4
|
|
; lda #MOCK_AY_INACTIVE ; go inactive ; 2
|
|
; sta MOCK_6522_ORB1 ; 4
|
|
; sta MOCK_6522_ORB2 ; 4
|
|
;
|
|
; value
|
|
; lda REGISTER_DUMP,X ; load register value ; 4
|
|
; sta MOCK_6522_ORA1 ; put value on PA1 ; 4
|
|
; sta MOCK_6522_ORA2 ; put value on PA2 ; 4
|
|
; lda #MOCK_AY_WRITE ; ; 2
|
|
; sta MOCK_6522_ORB1 ; write on PB1 ; 4
|
|
; sta MOCK_6522_ORB2 ; write on PB2 ; 4
|
|
; lda #MOCK_AY_INACTIVE ; go inactive ; 2
|
|
; sta MOCK_6522_ORB1 ; 4
|
|
; sta MOCK_6522_ORB2 ; 4
|
|
;===========
|
|
; 62
|
|
mb_no_write_12:
|
|
inx ; point to next register ; 2
|
|
|
|
;mb_write_loop_13:
|
|
; lda REGISTER_DUMP,X ; load register value ; 4
|
|
; cmp REGISTER_OLD,X ; compare with old values ; 4
|
|
; beq mb_no_write_13 ; 3/2nt
|
|
|
|
;mb_write_13:
|
|
|
|
; special case R13. If it is 0xff, then don't update
|
|
; otherwise might spuriously reset the envelope settings
|
|
|
|
; cmp #$ff ; 2
|
|
; beq mb_no_write_13 ; 3/2nt
|
|
|
|
|
|
; address
|
|
; stx MOCK_6522_ORA1 ; put address on PA1 ; 4
|
|
; stx MOCK_6522_ORA2 ; put address on PA2 ; 4
|
|
; lda #MOCK_AY_LATCH_ADDR ; latch_address for PB1 ; 2
|
|
; sta MOCK_6522_ORB1 ; latch_address on PB1 ; 4
|
|
; sta MOCK_6522_ORB2 ; latch_address on PB2 ; 4
|
|
; lda #MOCK_AY_INACTIVE ; go inactive ; 2
|
|
; sta MOCK_6522_ORB1 ; 4
|
|
; sta MOCK_6522_ORB2 ; 4
|
|
|
|
; value
|
|
; lda REGISTER_DUMP,X ; load register value ; 4
|
|
; sta MOCK_6522_ORA1 ; put value on PA1 ; 4
|
|
; sta MOCK_6522_ORA2 ; put value on PA2 ; 4
|
|
; lda #MOCK_AY_WRITE ; ; 2
|
|
; sta MOCK_6522_ORB1 ; write on PB1 ; 4
|
|
; sta MOCK_6522_ORB2 ; write on PB2 ; 4
|
|
; lda #MOCK_AY_INACTIVE ; go inactive ; 2
|
|
; sta MOCK_6522_ORB1 ; 4
|
|
; sta MOCK_6522_ORB2 ; 4
|
|
;===========
|
|
; 62
|
|
mb_no_write_13:
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
;=====================================
|
|
; Copy registers to old
|
|
;=====================================
|
|
ldx #13 ; 2
|
|
mb_reg_copy:
|
|
lda REGISTER_DUMP,X ; load register value ; 4
|
|
sta REGISTER_OLD,X ; compare with old values ; 4
|
|
dex ; 2
|
|
bpl mb_reg_copy ; 2nt/3
|
|
;=============
|
|
; 171
|
|
|
|
;===================================
|
|
; Load all 14 registers in advance
|
|
;===================================
|
|
; note, assuming not cross page boundary, not any slower
|
|
; then loading from zero page?
|
|
|
|
mb_load_values:
|
|
|
|
ldx #0 ; set up reg count ; 2
|
|
ldy MB_CHUNK_OFFSET ; get chunk offset ; 3
|
|
;=============
|
|
; 5
|
|
|
|
mb_load_loop:
|
|
lda (INL),y ; load register value ; 5
|
|
sta REGISTER_DUMP,X ; 4
|
|
;============
|
|
; 9
|
|
;====================
|
|
; point to next page
|
|
;====================
|
|
|
|
clc ; point to next interleaved ; 2
|
|
lda INH ; page by adding CHUNKSIZE (3/1); 3
|
|
adc CHUNKSIZE ; 3
|
|
sta INH ; 3
|
|
|
|
inx ; point to next register ; 2
|
|
cpx #14 ; if 14 we're done ; 2
|
|
bmi mb_load_loop ; otherwise, loop ; 3/2nt
|
|
;============
|
|
; 18
|
|
|
|
|
|
|
|
;==============================================
|
|
; incremement offset. If 0 move to next chunk
|
|
;==============================================
|
|
|
|
increment_offset:
|
|
|
|
inc MB_CHUNK_OFFSET ; increment offset ; 5
|
|
|
|
lda #0 ; 2
|
|
clc ; 2
|
|
adc #>UNPACK_BUFFER ; in proper chunk 1 or 2 ; 2
|
|
sta INH ; update r0 pointer ; 3
|
|
|
|
|
|
|
|
;=================================
|
|
; Finally done with this interrupt
|
|
;=================================
|
|
|
|
done_interrupt:
|
|
pla ; restore a ; 4
|
|
rti ; return from interrupt ; 6
|
|
|
|
|
|
REGISTER_OLD:
|
|
.byte 0,0,0,0,0,0,0,0,0,0,0,0,0,0
|
|
|
|
.align 256
|
|
UNPACK_BUFFER:
|
|
.incbin "sdemo.raw"
|