Files
open-roms/c64/kernal/setfls.s
T

21 lines
452 B
ArmAsm

;;
;; Official Kernal routine, described in:
;;
;; - [RG64] C64 Programmer's Reference Guide - page 297
;; - [CM64] Compute's Mapping the Commodore 64 - page 238
;;
;; CPU registers that has to be preserved (see [RG64]): .A, .X, .Y
;;
setfls:
;; There are 6 sane ways to implement this routine,
;; I hope this one won't cause similarity to CBM code
sta current_logical_filenum
sty current_secondary_address
stx current_device_number
rts