Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ncar!noao!asuvax!hrc!xroads!aman
From: aman@xroads.UUCP (Chris Minshall)
Newsgroups: comp.sys.amiga
Subject: Atari ST Emulation
Keywords: [AATARI ST Emulation Amiga 1000 500 2000 2500 1040 520 Mega
Message-ID: <686@xroads.UUCP>
Date: 7 May 89 06:20:04 GMT
Distribution: na
Organization: Crossroads, Phoenix, Az
Lines: 28


I am going to write an Atari ST emulator for the Amiga.  I have never written
a hardware emulator before and have been "brain-storming" as to how to go
about accomplishing the task.  I am NOT a novice or intermediate programmer
but rather consider myself a semi-pro!  So, I am wondering if anyone out
there has written hardware emulators and could give me some tips as to where
to begin.  I own both an Amiga 1000 and Atari 1040ST.  I am debateing as to
whether or not I will incorporate a hardware device for the rom chips (ala
the macintosh emulators available on both the ST and Amiga) or to take a copy
of the TOS roms from the ST and make it internal to the emulator program.  I
am wondering how to go about the actual emulation of some of the "special"
chips inside the ST.  Specifically, how to write an disk driver for reading
ST disks and emulation of the video controller, dma chip, disk controller?
Then, how to incorporate the emulation of those chips (or should I say the 
various registers within the chips?) into the execution of an application
running on the emulator (i.e. trapping an ST application that tries to read
or write to a memory location that one of the special chips is mapped to and
re-routing the application to the proper emulation of that register)?  Well,
I hope there is enough software engineers out there that might be able to
help me out on this.  I don't really intend to ever market this sucker
commercially (unless someone offers to buy it!) but rather to offer it in the
"shareware" variety!  Please, anyone who can help me, please leave me some
mail!!!   Thanks.
                                        Chris Minshall
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