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From: MTHOLDWI@MTUS5.BITNET (Holdwick, Marc T.)
Newsgroups: comp.sys.mac.hardware
Subject: Homebrew Accelerator Board
Message-ID: <91029.174426MTHOLDWI@MTUS5.BITNET>
Date: 29 Jan 91 22:44:26 GMT
Organization: Computing Technology Services, Michigan Technological Univ.
Lines: 26

Hi!  I own a Mac SE and I would like an accelerator to speed things up a little
but (like many) I cannot afford one now...

I am fairly knowledgeable about computer hardware and I am thinking about
building my own accelerator.

I own the Macintosh Technical Reference manual and have access to Motorola
68020 and 68030 manuals.  I have seen the Apple book, "Designing cards and
drivers for the Mac SE and II", but I forget If they talk about accelerators
at all.  Do they, and is it helpfull?

My main questions are:  I know that the '020 and '030 can handle the 16bit data
buss, but what do I do with the upper 8 bits of the address bus?

The '020 and '030 are supposed to be compatable with the 68000's instructions.
The instruction cache aside, are there any other software problems I have to
worry about?  Or will I have to write some drivers?

I also have a few questions on the timing aspect of this project.  Most
deal with software considerations such as timing dependent code in ROM.

I remember a previous post about someone doing what I hope to do.  If you know
who posted before, or if you have built one, or know something that might help
me, I would REALLY appreciate hearing from you!

                                             Thanks!