21 lines
291 B
ArmAsm
21 lines
291 B
ArmAsm
.globl backspace
|
|
.globl lookchar
|
|
.globl w, r, a, l
|
|
/
|
|
/ routine to read a string backwards
|
|
/ the read pointer is decremented before reading
|
|
/
|
|
/ mov ...,r1
|
|
/ jsr pc,backspace
|
|
/ mov r0,...
|
|
/
|
|
backspace:
|
|
cmp a(r1),r(r1)
|
|
bhis nochc
|
|
dec r(r1)
|
|
jsr pc,lookchar
|
|
rts pc
|
|
nochc: clr r0
|
|
sec
|
|
rts pc
|