Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!iuvax!silver!beversdo
From: beversdo@silver.bacs.indiana.edu (Tom Beversdorf    )
Newsgroups: comp.sys.apple
Subject: Hyper-C now fixed on an Apple IIgs.
Message-ID: <21462@iuvax.cs.indiana.edu>
Date: 1 Jun 89 03:13:49 GMT
Sender: root@iuvax.cs.indiana.edu
Reply-To: beversdo@silver.bacs.indiana.edu (Tom Beversdorf    )
Distribution: usa
Organization: Indiana University, Bloomington
Lines: 75

I discovered the problem on the Hyper-C which wouldn't run on a IIgs
computer because it intended to execute a "BRK" instruction.  The BRK
on an Apple //e stays in the language card while an Apple IIgs switched
into ROM memory.

The Solution:

    Go to the monitor on an Apple IIgs computer, type:

        *E1/0010:5C D4 D0 00
        *6^p
Then that should work.

Another Solution:

    Go to the sector editor:

    On Track 0, Sector 3:
    Starting Byte B8:
    Change them to 20 D0 F5 EA EA EA EA EA EA.

    On Track 3, Sector E:
    Byte C0 through the near end of the sector:

    AD 81 C0 38 20 1F FE AD  83 C0 AD 83 C0 60 00 00
    A2 0D BD C0 F5 9D 00 03  CA 10 F7 20 00 03 90 0B
    A9 D4 8D FE FF A9 D0 8D  FF FF 60 A2 03 BD F8 F5
    9F 10 00 E1 CA 10 F6 60  5C D4 D0 00 .. .. .. ..

That should also work (if you don't have to bother with monitor command
everytime you start up with Hyper-C on an Apple IIgs.

----

Technical Information of how to fix Hyper-C on an Apple IIgs:

At first, after the Hyper-C has been booted up and the system is loaded,
it checks for the machine-ID for IIgs, but we had a problem.  First, the
code had to be moved into the main RAM memory such as $0300 to switch the
ROM w/ Language Card and checks for an ID and return to the Language Card
routine.  If that is a IIgs specific, then it writes into bank E1 address
0010, the IIgs interrupt vector, to jump to cold start.  If not, then it
writes the Language Card FFFE and FFFF to D0D4.

Assembly Listing for Hyper-C modification:

GS_CHECK    LDA $C081        ;Enables the ROM memory
            SEC              ;Suppose that is non-IIgs specific
            JSR $FE1F        ;Machine ID - Check for IIgs.
            LDA $C083        ;Enables the Language Card
            LDA $C083        ;Enables write to Language Card
            RTS
ENDCHK      EQU *            ;End of Checking Code.

START       LDX #ENDCHK-GS_CHECK
LOOP1       LDA GS_CHECK,X   ;Move the code out of the Language Card so
            STA $300,x       ;we can swap the ROM w/ Language Card.
            DEX
            BPL LOOP1
            JSR $300         ;Do a Machine ID code.
            BCC IIGS         ;if Carry bit is clear, then IIgs,
            LDA #$D4         ;else //e, //c.
            STA $FFFE
            LDA #$D0
            STA $FFFF
            RTS
IIGS        LDX #$03
LOOP2       LDA JMLCODE,X
            STA $E10010,X
            DEX
            BPL LOOP2
            RTS
JMLCODE     JMP $00D0D4

Mine works on the modification of Hyper-C.