From: hamachi@adobe.com (Gordon Hamachi)
Newsgroups: comp.sys.mac.hardware
Subject: Re: Plus Accelerator?
Date: 14 Sep 92 19:37:37 GMT
Distribution: usa
Organization: Adobe Systems Incorporated

Steve Klarer writes
> A few weeks ago someone mentioned an accelerator of some sort which, they
> said, made a MacPlus run at about 4 times its normal speed.

That would be the Brainstorm accelerator.  I recently bought one and installed  
it myself.  Here's what I know:

The list price is $250, though there's some place in MacWeek that occasionally  
advertises a Brainstorm accelerator installed for about $190.  If you are  
affiliated with an educational institution you can get one for $149 plus tax  
and shipping.  But if you go this route you have to install it yourself and the  
normal 1 year warranty is void.  Installation requires some PC board soldering,  
so it is not for everyone.

The accelerator consists of a low power 16 MHz 68000 processor on a small  
daughterboard only a little larger than the processor itself.  Also on the  
board is a DIP.  On the flip side are two surface mount packages.  You solder a  
socket directly to your Mac Plus's processor, then insert the daughterboard  
into the socket.  You also have to unsolder a 20-pin bus timing chip, install a  
socket, and insert Brainstorm's custom replacement.  Finally, there are 2 flat  
capacitors that mount between your ROM chips and their sockets.

The hardware comes with a small 3-ring binder of documentation and a floppy  
disk containing the firmware installer.  The manual describes the theory of  
operation, and tells you how to run the installer.  Also included are a  
trouble-shooting flow chart and some notes on compatibility.  The documentation  
goes into some detail concerning hard disk interleave and also has some general  
tips on how to get greater performance out of your machine.

When I installed my accelerator it didn't work.  But even though there was no  
warranty for self-installation, Brainstorm helped me diagnose the problem,  
offered to swap a suspected bad chip, and gave me information to fix the  
problem.  When I unsoldered the bus timing chip, I had broken a PC board trace.   
This is probably because I saved the old chip (bad idea), rather than following  
their instructions to cut off the old chip's pins and pull them out one-by-one.   
Brainstorm told me which chip to look at, and gave me a net list and PC board  
diagram.  I had to find the break myself, but one blue wire later I was up and  
running again.

I have found a small number of incompatibilities.  My flight simulators (Falcon  
F-16 and Fokker triplane) still run, but are harder to control because  
everything happens faster.  Some, but not all applications have trouble with  
sound; Brainstorm provides firmware to mitigate the problem.  You need to run  
System 6.0.7 or later.  The accelerator doesn't work with hard disk drivers  
that use blind transfers.  My Dataframe XP60 does work, but the disk has to  
spin up before I turn on my Mac; previously I could turn both at the same time  
and it would boot successfully.

Before I did my own measurements, I was skeptical of Brainstorm's performance  
claims.  How could a processor only twice as fast result in a performance boost  
of more than 2X?  But my own casual benchmarks show the Brainstorm accelerator  
is 2 to 3 times as fast as a stock Mac Plus.  Hypercard and Adobe Illustrator  
are fast enough to be tolerable; previously, they were painfully slow.

My one minor complaint is that the Brainstorm logo displays when I boot my  
machine.  Overall I am quite pleased and recommend the Brainstorm accelerator  
to anyone as an inexpensive way to get a little more useful life out of an old  
obsolete machine.

I have no affiliation with Brainstorm, other than as a satisfied customer.

Brainstorm Products
1145 Terra Bella Avenue
Mountain View, Calif. 94043
415/964-2131
Fax: 415/964-2135
AppleLink: D6800
America OnLine: Brnstrm16

--Gordon Hamachi
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