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https://github.com/ksherlock/itty-bitty-vtty.git
synced 2024-11-21 20:30:56 +00:00
move code to $6000 since $0800 interferes w/ text page 2.
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parent
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42
boot.S
42
boot.S
@ -2,10 +2,15 @@
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* boot block.
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*
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* loaded at $0800
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* relocates everything to $6000, loads extra blocks, and runs main.
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xc
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xc
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rel
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* org $0800
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ORG equ $6000
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SLOT equ $00
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CMD equ $42
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@ -13,7 +18,7 @@ UNIT equ $43
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BUFFER equ $44
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BLOCK equ $46
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ext init
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ext main
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boot
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mx %11
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@ -28,9 +33,14 @@ boot
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* lsr
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* lsr
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* ora #$c0
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ldy #END-boot
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:cp lda $0800,y ; boot,y
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sta ORG,y
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dey
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bne :cp
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jmp ORG+:entry-boot
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stx UNIT
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:entry stx UNIT
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txa
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lsr
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lsr
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@ -59,12 +69,12 @@ boot
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sta :prodos+1
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lda #1
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lda #1 ; read block
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sta CMD
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sta BLOCK
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stz BLOCK+1
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stz BUFFER
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lda #$a0 ; $0800+512
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lda #>{ORG+512} ; $0800+512
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sta BUFFER+1
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:read
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@ -83,18 +93,24 @@ boot
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:ok
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clc
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xce
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cli
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jsr init
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jmp main
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noboot
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:loop wai
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bra :loop
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ldx #0
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:cout lda :str,x
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beq :wai
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jsr $fded
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inx
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bra :cout
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:wai wai
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bra :wai
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:str asc "** BOOT ERROR **",00
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END
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err *-boot>$ff
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* fill to end of block since only 255 bytes relocated.
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ds boot+512-*
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sav boot.L
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