23 lines
545 B
ArmAsm
23 lines
545 B
ArmAsm
|
.define Mprint
|
||
|
|
|
||
|
|
! This subroutine prints a zero terminated ascii string.
|
||
|
|
! The registerpair AX contains the start of the string.
|
||
|
|
! The subroutine WRCH is a special routine on the BBC microcomputer
|
||
|
|
! which prints the character in A to the screen.
|
||
|
|
! The subroutine WRCH is a special one provided by the BBC
|
||
|
|
! microcomputer.
|
||
|
|
|
||
|
|
|
||
|
|
Mprint:
|
||
|
|
stx ADDR ! start address of string (lowbyte)
|
||
|
|
sta ADDR+1 ! start address of string (highbyte)
|
||
|
|
ldy #0
|
||
|
|
1: lda (ADDR),y ! get ascii character
|
||
|
|
beq 2f
|
||
|
|
jsr WRCH ! put it on the screen
|
||
|
|
iny
|
||
|
|
bne 1b
|
||
|
|
2: rts
|
||
|
|
|
||
|
|
|