33 lines
704 B
ArmAsm
33 lines
704 B
ArmAsm
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.define Mread
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! This subroutine reads characters from the standard input.
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! It ignores the filedes.
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! It reads atmost 255 characters. So the runtime system must
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! provide a way of dealing with this.
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! The subroutine RDCH is a special one provided by the BBC
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! microcomputer.
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Mread:
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jsr Pop ! ignore filedescriptor
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jsr Pop ! bufptr
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stx ADDR ! address of character buffer (lowbyte)
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sta ADDR+1 ! address of character buffer (highbyte)
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jsr Pop ! number of characters
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ldy #0 ! <= 255
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inx
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1: jsr RDCH ! read a character from the current inputstream
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bcs 8f
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sta (ADDR),y
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iny
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dex
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bne 1b
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8: tya
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tax
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lda #0
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jsr Push ! number of characters red.
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tax ! report a succesfull read.
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rts
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