ack/plat/cpm/libsys/_bios.s
2019-11-23 11:31:03 +01:00

23 lines
421 B
ArmAsm

#
#include "asm.h"
! Calls a BIOS routine which returns its value in A.
! a = BIOS offset
.define call_bios_a
call_bios_a:
pop h ! pop return address
pop d ! pop parameter (possibly junk)
push d
push h
push b ! save FP as we'll corrupt it
mov b, d ! put parameter in BC
mov c, e
call call_bios_raw
pop b
mov e, a ! put result in DE
mvi d, 0
ret