Path: utzoo!attcan!uunet!seismo!sundc!pitstop!sun!decwrl!ucbvax!DMZRZU71.BITNET!KAPFFER
From: KAPFFER@DMZRZU71.BITNET (Matthias Kapffer)
Newsgroups: comp.sys.apple
Subject: Re: //GS bank switch mem probs
Message-ID: <8805120435.aa04163@SMOKE.BRL.ARPA>
Date: 12 May 88 09:02:53 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 19
X-Unparsable-Date: Tue, 10. May 1988   19:12 CET

Jeff,

the  Apple IIgs has no real compatiblity mode (like GO64 on a C= 128) but just
a  lot  of  single  options like shadowing of video buffers (but not text page
2...   )  and  the  I/O area, emulation vs native mode of the 65816 (don't mix
this  up  with  Apple //e - Apple IIgs compatiblity !), CPU speed etc.  All of
the  advanced  features  of  a  IIgs  can  be  used  by  programs  running  in
"emulation".

To  come  down  to  your specific problem, the hardware of the "language card"
doesn't  cause  any troubles, but the monitor activly manages the state of the
banked  switched  RAM  in  this  area  to  offer  unlimited  access to it (the
appropriate ROMs can be read in bank $FF anyway).  This causes some EXEC files
to  crash  which  use monitor commands to switch over to the RAM and load some
files  into  it.   Also  "G" commands will always call the ROM in this address
range.

                                        Matthias Kapffer