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- .define Printhex
- .sect .text
- .sect .rom
- .sect .data
- .sect .bss
- .sect .text
- ! This subroutine print the contents of register A to the screen
- ! in hexadecimal form.
- ! The subroutine WRCH is a special one provided by the BBC
- ! microcomputer.
- Printhex:
- pha ! save A
- lsr a
- lsr a
- lsr a
- lsr a ! get four high bits
- jsr 1f
- pla ! restore A
- and #0x0F ! get four low bits
- jsr 1f
- rts
- 1: sed ! print in hex
- clc
- adc #0x90
- adc #0x40
- cld
- jmp WRCH
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