55 lines
1.5 KiB
ArmAsm
55 lines
1.5 KiB
ArmAsm
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; ---------------------------------------------------------------------------
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; read.s
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;
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; for Sym-1
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;
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; Wayne Parham
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;
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; wayne@parhamdata.com
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; ---------------------------------------------------------------------------
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.include "sym1.inc"
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.import popax, popptr1
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.importzp ptr1, ptr2, ptr3
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.export _read
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.proc _read
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; ---------------------------------------------------------------------------
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sta ptr3
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stx ptr3+1 ; Count in ptr3
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inx
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stx ptr2+1 ; Increment and store in ptr2
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tax
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inx
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stx ptr2
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jsr popptr1 ; Buffer address in ptr1
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jsr popax
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begin: dec ptr2
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bne getch
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dec ptr2+1
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beq done ; If buffer full, return
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getch: jsr INTCHR ; Get character using Monitor ROM call
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jsr OUTCHR ; Echo it
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and #$7F ; Clear hi bit and check for '\r'
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cmp #$0D
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bne putch
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lda #$0A ; Replace with '\n' and set count to zero
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putch: ldy #$00 ; Put char into return buffer
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sta (ptr1),y
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inc ptr1 ; Increment pointer
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bne begin
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inc ptr1+1
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bne begin
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done: lda ptr3
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ldx ptr3+1
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rts ; Return count
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; ---------------------------------------------------------------------------
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.endproc
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