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From: des7f@uvacs.cs.Virginia.EDU (David Sappington)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Reforming Mac Programming
Summary: trap F000 instructions on machines w/o 6888x
Message-ID: <1169@ra.cs.Virginia.EDU>
Date: 29 Mar 90 01:42:32 GMT
References: <13828@eagle.wesleyan.edu> <5492@okstate.UUCP>
Sender: daemon@ra.cs.Virginia.EDU
Reply-To: des7f@uvacs.cs.Virginia.EDU (David Sappington)
Organization: University of Virginia Computer Science Department
Lines: 19

[ much discussion of using SANE vs. direct calls to the FPU ]

Shipping a floating point intensive application that doesn't have a
version using direct calls to the FPU should be a crime!!

Why oh why doesn't Apple include a 6888x emulation package with their
system software?  Just as the Mac's trap dispatcher handles Axxx
"instructions", Apple could easily set up a dispatcher to handle the
Fxxx floating point "instructions" on machines w/o an FPU.  Everyone
could then use direct calls to the FPU and still have their programs
run on a Plus or SE.

68020 instructions that are not available on the 68000 could also
be emulated by using the "illegal instruction" trap but I don't know
if it would be worth doing.

Dave Sappington                         des7f@virginia.edu
Institute for Parallel Computation      des7f@virginia.BITNET
University of Virginia