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

26 lines
555 B
ArmAsm

;;
;; Official Kernal routine, described in:
;;
;; - [RG64] C64 Programmer's Reference Guide - page 276
;; - [CM64] Compute's Mapping the Commodore 64 - page 229
;;
;; CPU registers that has to be preserved (see [RG64]): .Y
;;
chkout:
;; Implemented according to 'C64 Programmers Reference Guide', page 278
;; First retrieve the FAT/LAT/SAT table index (and check if file is open)
; txa
; jsr find_fls
; bcs kernalerror_FILE_NOT_OPEN
;; Now we have table index in Y - check if file is open for writing
;; XXX continue implementation
rts