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https://github.com/st3fan/ewm.git
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25 lines
829 B
ArmAsm
25 lines
829 B
ArmAsm
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.ORG $8000
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KBD = $D010 ; PIA.A keyboard input
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KBDCR = $D011 ; PIA.A keyboard control register
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DSP = $D012 ; PIA.B display output register
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DSPCR = $D013 ; PIA.B display control register
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MAIN: JSR GETC ;
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JSR PUTC ;
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CMP #$03 ;
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BNE MAIN ;
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BRK ;
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GETC: LDA KBDCR ;
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BPL GETC ; Do we have a character?
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LDA KBD ; Yup, load it
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RTS ;
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PUTC: BIT DSP ; Bit (B7) cleared yet?
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BMI PUTC ; No, wait for display
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STA DSP ; Yup, send it to the display
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RTS ;
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