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From: drtiller@uokmax.ecn.uoknor.edu (Donald Richard Tillery Jr)
Newsgroups: comp.sys.amiga.emulations
Subject: IBeM on a GVP A3001 and speeding the thing up.
Message-ID: <1991Mar8.003734.18281@uokmax.ecn.uoknor.edu>
Date: 8 Mar 91 00:37:34 GMT
Organization: Engineering Computer Network, University of Oklahoma, Norman, OK
Lines: 30

GVP has verified that indeed Mark Tomlinson has included odd word aligned
references in his IBM emulator, IBeM.  This is the reason that neither the
GVP accelerator nor the Hurricane 2800 will run his software.  Although
this is strictly legal for the 68020/030 CPU, it is referenced as a no-no
by Motorola AND Commodore and was thus built out of these two accelerators.

Mark, I know you said that this wasn't your fault, but it might interest you
to know that (according to GVP) there are more GVP accelerators in Amigas
than Commodore A2620s AND A2630s combined.  I hope this and the following
is enough motivation for you to re-write your code without the boundary
violation.

While discussing this with GVP, it also came up that any long word reference
to 32 bit memory and any long word or word reference to fast memory would
require _2_ memory references and thus take double the amount of access time.
I don't know how many odd word references are in IBeM, but if there are many,
the speed improvement could be QUITE noticable (albeit the code size might
increase by a hair).

Please consider adjusting your code to take this into account and if you
have any questions or comments that I can relay to the rather knowledgable
GVP staff (probably much cheaper from this side of the pond), please don't
hesitate to let me know.

In the mean time, does the $30 registration fee include future updates for
serial, parallel, sound, 8087 emulation, and possible EGA support?

Thanks for your support.

Rick Tillery (drtiller@uokmax.ecn.uoknor.edu)