Save and load: drverr

       Name: drverr                                                  [Show more]
       Type: Subroutine
   Category: Save and load
    Summary: Return from the RWTS code with a "Disk I/O error"
    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * trytrk calls drverr


 Returns:

   A                    The error number for the Disk I/O error (4)

   C flag               The C flag is set


.drverr

 PLP                    ; Pull the read/write status off the stack as we don't
                        ; need it there any more

 LDY mtroff,X           ; Read the disk controller I/O soft switch at MOTOROFF
                        ; for slot X to turn the disk motor off

 SEC                    ; Set the C flag to denote that an error has occurred

 LDA #4                 ; Set A = 4 to return as the error number for the "Disk
                        ; I/O error"

 RTS                    ; Return from the subroutine