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C02/include/prbyte.a02
2018-11-07 00:11:09 -05:00

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;Assembly Header Include File for platforms
;that do not have PRBYTE amnd PRHEX routines in ROM
;Print Byte as Two-Digit Hex Number to Console
PRBYTE: PHA ;Save Accumulater
LSR ;Shift Hi Nybble to Low Nybble
LSR
LSR
LSR
JSR PRHEX ; and Print it
PLA ;Restore Accumulator
; and fall into prhex
;Print Low Nybble as Hex Digit to Console
PRHEX: AND #$0F ;Strip High Nybble
CMP #$0A ;If Low Nybble >= 10
BCC PRHEXC ;
ADC #$06 ; Convert ':' to 'A'...
PRHEXC: ADC #$30 ;Convert to ASCII Character
JMP PUTCHR ;Print Hex Digit and Return