Loader: Elite GMA loader (Part 2 of 4)

       Name: Elite GMA loader (Part 2 of 4)                          [Show more]
       Type: Subroutine
   Category: Loader
    Summary: Offer the option of a fast loader and run the disk protection code
             in the GMA3 file
    Context: See this subroutine in context in the source code
 References: No direct references to this subroutine in this source file


.load1

 LDA #%00000000         ; Call the Kernal's SETMSG function to set the system
 JSR KERNALSETMSG       ; error display switch as follows:
                        ;
                        ;   * Bit 6 clear = do not display I/O error messages
                        ;
                        ;   * Bit 7 clear = do not display system messages
                        ;
                        ; This ensures that any file system errors are hidden

 LDA #$FF               ; Set the high byte of the execution address of STOP to
 STA $0329              ; $FF, from the default $F6ED to $FFED
                        ;
                        ; The address $FFED in the Kernal ROM simply returns
                        ; without doing anything, so this effectively disables
                        ; the RUN/STOP key

 JSR OfferFastLoader    ; Ask whether we want to use the fast loader, and if we
                        ; do, configure it to intercept the Kernal functions for
                        ; loading files

IF _GMA86_PAL

 LDA #3                 ; Call LoadGMAFile to load the GMA3 file, which contains
 JSR LoadGMAFile        ; the disk copy protection

ELIF _GMA85_NTSC

 LDA #'3'               ; Call LoadGMAFile to load the GMA3 file, which contains
 JSR LoadGMAFile        ; the disk copy protection

ENDIF

 JSR $C800              ; Call the disk copy protection code in GMA3 (this call
                        ; gets disabled by elite-checksum.py)

IF _GMA86_PAL

 LDA $02                ; If the result of the disk copy protection in address
 EOR #$97               ; $0002 is $97, then jump to load2 to skip the following
 BEQ load2              ; (this check gets disabled by elite-checksum.py)

 JMP ($FFFC)            ; Otherwise we have failed the disk protection checks,
                        ; so jump to the address in $FFFC to reset the machine

.load2

ENDIF