mirror of
https://github.com/ksherlock/itty-bitty-vtty.git
synced 2024-11-27 13:53:28 +00:00
237 lines
2.1 KiB
ArmAsm
237 lines
2.1 KiB
ArmAsm
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lst off
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exp off
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*
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* read modem port
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*
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*
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cmdb equ $c038
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cmda equ $c039
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datab equ $c03a
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dataa equ $c03b
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cout equ $fded
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read mac
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ldx #]1
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if 3=]1
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stx cmda
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lda cmda
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else
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stx cmdb
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lda cmdb
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fin
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sta buffer,x
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<<<
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lst on
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org $0800
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mx %11
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db $01 ; prodos boot id
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boot
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* clc
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* xce
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* cli
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sei
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ldx #24
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lda #$80+$0d
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:cs jsr cout
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dex
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bpl :cs
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* just in case.
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lda cmdb
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lda cmdb
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init
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* reset channel b
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ldx #9
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lda #%01010001
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stx cmdb
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sta cmdb
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nop
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nop
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* x16 clock mode, 1 stop bit, no parity
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ldx #4
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lda #%01000100
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stx cmdb
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sta cmdb
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* 8 bits/char, rx disabled.
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ldx #3
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lda #%11000000
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stx cmdb
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sta cmdb
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* 8 data bits, RTS
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ldx #5
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lda #%01100010
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stx cmdb
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sta cmdb
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ldx #11
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lda #%01010000
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stx cmdb
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sta cmdb
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* 9600 baud
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ldx #12
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lda #10
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stx cmdb
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sta cmdb
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* 9600 baud
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ldx #13
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lda #0
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stx cmdb
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sta cmdb
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* disable baud rate generator
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ldx #14
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lda #0
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stx cmdb
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sta cmdb
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* enable baud rate generator
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ldx #14
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lda #%00000001
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stx cmdb
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sta cmdb
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* 8 bits/char, rx enabled.
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ldx #3
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lda #%11000001
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stx cmdb
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sta cmdb
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* 8 data bits, tx enabled, RTS
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ldx #5
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lda #%01101010
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stx cmdb
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sta cmdb
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* disable interrupts
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ldx #15
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lda #0
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stx cmdb
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sta cmdb
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* reset ext/status interrupts
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ldx #0
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lda #%00010000
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stx cmdb
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sta cmdb
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* disable interrupts
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ldx #1
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lda #0
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stx cmdb
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sta cmdb
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* reset ch b ptr to 0?
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lda cmdb
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* status, visible, master interrupts disabled
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ldx #9
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lda #%00010001
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stx cmdb
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sta cmdb
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nop
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nop
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* read registers - 0, 1, 2, 3, 8, 10, 12, 13, 15
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* 3 is channel A only.
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loop
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read 0
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read 1
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read 2
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read 3
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read 8
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read 10
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read 12
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read 13
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read 15
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ldx #15
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:cmp lda buffer,x
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cmp prev,x
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bne :delta
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dex
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bpl :cmp
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bra wailoop
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:delta
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ldx #0
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:print
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lda buffer,x
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phx
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pha
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lsr
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lsr
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lsr
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lsr
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tax
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lda hex,x
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jsr cout
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pla
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and #$0f
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tax
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lda hex,x
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jsr cout
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lda #" "
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jsr cout
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plx
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inx
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cpx #16
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bcc :print
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lda #$80+$0d
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jsr cout
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* store prev. values.
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ldx #15
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:copy lda buffer,x
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sta prev,x
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dex
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bpl :copy
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wailoop
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* wai
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brl loop
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nop
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nop
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stp
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hex asc "0123456789abcdef"
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buffer ds 16
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prev ds 16
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lst off
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* ds \
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ds 1024+$0800-*
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sav modem.bin |