Description: Apple II, IIe and II+: Auto-Run Apple w/o DOS (2 of 2)
Header: Apple II, IIe and II+: Auto-Run Apple w/o DOS (2 of 2)


 Article Created: 21 September 1984
 Article Last Reviewed: 3 May 1988
 Article Last Updated: 3 May 1988

 For the next step a copy of the image of the application program needs to be
 programmed into the EPROMs.  The program starts at the address pointed to by
 $67 and $68 and ends at the address pointed to by $AF and $B0.  The contents
 of the end address pointer, $AF and $B0, will be inserted in the control ROM
 at locations $1F and $23.  When control comes back through the input routine
 pointer, Applesoft has already initialized $67 and $68.  So the next step is
 to move the image of the Applesoft program down to where it originally came
 from.  How this is done will depend on the hardware of the ROM card and the
 length of the Applesoft program.  If you use the Apple firmware card you will
 have to address the soft switch to select the firmware card and then address
 the switch again to re-select the Applesoft ROMs.  With the ROMPLUS it could
 be as simple as using the monitor move routine, $FE2C, to move a program of
 less than 2 kilobytes long.

 There is a little more initialization to be done before the Applesoft program
 can be RUN.  The end of program pointer mentioned earlier must be put into $69
 and $6A and one more Applesoft routine must be called.  Unfortunately this one
 also drops into Applesoft's command mode so we have to modify the input
 pointer again to point to a third part of the control ROM. Once this is done
 the final initialization can be done with a jump to $D4F2.

 And now the final part, we need to reset the input pointer so that the program
 can input normally from the keyboard and actually RUN the program.  To make
 things easier there is a routine set by the Auto-Start ROM that will set the
 input pointers to the keyboard at location $FE89.  Then all that's left to do
 is jump to $D566 which will run the program.

 For a bit of finesse, if we put a $80 into location $D6, the user will not be
 able to list the program.  In fact any attempt to do any Applesoft command
 except LOAD from cassette will cause the program to RUN.  Also, by changing
 the reset vectors in the Auto-Start ROM to point to the RUN routine, the
 program will become very difficult to stop or modify.  (To change the reset
 vector, load memory starting at $3F2 with 66 D5 70.  See page 36 and 37 of the
 Apple II Reference manual for more details)

 THE LISTING

 This listing is all done relative to the start of the ROM so all address are
 given as one byte.  If you use an assembler, simply origin the code in RAM and
 when it is programmed into the control ROM it will work just fine.  The
 routines are not arranged in order of execution so that the move routine will
 be at the end since the length of the move routine will vary with the hardware
 requirements.  Just be sure that the three byte jump is inserted behind the
 move routine.

 * THE FIRST 4 INSTRUCTIONS LOOK LIKE A DISK BUT DON'T
 * DO ANYTHING
 *
 00: 24 20      BIT $20
 02: 24 00      BIT $00
 04: 24 03      BIT $03
 06: 24 3C      BIT $3C
 *
 * THIS PART INITIALIZES APPLESOFT AND GETS CONTROL BACK
 * AT ENTRY2
 *
 08: A9 1A      ENTRY1  LDA # ENTRY2
 0A: 85 38              STA KSWL
 0C: A5 F8 07           LDA $07F8
 0F: 85 39              STA KSWH
 11: 4C 00 E0           JMP COLDSTART
 *
 * RESET INPUT TO THE KEYBOARD AND RUN THE PROGRAM
 *
 14: 20 8  1a   ENRTY3  JSR SETKBD
 17: 4C 66 D5           JMP RUN
 *
 * FINISH INITIALIZATION & MOVE THE PROGRAM TEXT DOWN
 * FROM THE ROMS
 *
 1A: A9 14      ENTRY2  LDA # ENTRY3
 1C: 85 38              STA KSWL
 1E: A9 LL              LDA # LENGTH-L
 20: 85 69              STA LOMEML
 22: A9 HH              LDA # LENGTH-H
 24: 85 6A              STA LOMEMH

 INSERT YOUR MOVE ROUTINE HERE FOLLOWED BY

  : 4C F2 D4           JMP INIT PART 2
 Copyright 1984, 1988 Apple Computer, Inc.
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