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51 lines
1.2 KiB
ArmAsm
51 lines
1.2 KiB
ArmAsm
;
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; Ullrich von Bassewitz, 06.08.1998
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;
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; char cgetc (void);
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;
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.export _cgetc
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.import plot, write_crtc
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.import cursor
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.import keyidx: zp, keybuf: zp, config: zp
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_cgetc: lda keyidx ; Get number of characters
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bne L2 ; Jump if there are already chars waiting
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; Switch on the cursor if needed
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lda cursor
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beq L1 ; Jump if no cursor
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jsr plot ; Set the current cursor position
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ldy #10
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lda config ; Cursor format
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jsr write_crtc ; Set the cursor formar
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L1: lda keyidx
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beq L1
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ldy #10
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lda #$20 ; Cursor off
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jsr write_crtc
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L2: ldx #$00 ; Get index
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ldy keybuf ; Get first character in the buffer
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sei
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L3: lda keybuf+1,x ; Move up the remaining chars
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sta keybuf,x
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inx
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cpx keyidx
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bne L3
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dec keyidx
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cli
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ldx #$00 ; High byte
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tya ; First char from buffer
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rts
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