From: milton@ccu.umanitoba.ca (Dave Milton)
Subject: Accellerator FAQ - comment on this report. (LONG)
Organization: University of Manitoba, Winnipeg, Canada
Date: Fri, 10 Apr 1992 14:35:59 GMT

This group has a common question which pertains to accellerating a
Macintosh. A few years ago I did some research into the topic and
recently have been sending the report enclosed below to those who ask
about accellerators. Some of this information is now getting dated and
I would like your help in bringing things up to date.

Some of the things I would like to add are:
    - some information on 68030 accellerators
    - Are there any known conflicts with some accellerators?
    - Some accellerators _require_ software before they work - is there a
      list of these? 

Please send your comments to me via email and I will post the updated
report when my changes are complete. I will also post this report to
the sumex archives so others can benefit from the work.

Thanks in advance

Dave Milton, University of Manitoba, Winnipeg, Canada. (204)788-6346
Internet: <milton@ccu.UManitoba.CA>  Bitnet: <milton@UOFMCC>
-----------------

Subject: Re: MacPlus Upgrade/Accelerators

If the Mac you have still does what you want but is "just not fast
enough" then buy an accellerator. If the Mac simply cannot do the job
then start looking for a new Mac. Some of the things that no current
hardware will change is the addition of more serial ports, colour, 32
bit addressing, and in some cases larger monitors. Many accellerators
will not work with full page displays; you simply cannot have both.
Some accellerators won't break the 4M memory 'limit' of the Mac 512Ke
or MacPlus - you need something that can have VM to do this so the
4M memory limit may be another reason to consider a new Macintosh.
Finally, the sound manager does not work as well in an accellerated
Macintosh. If you are doing work with digitised sound then an
accellerator is definately not the answer. The MacPlus is a good
box; with an accellerator you may get another few years of use out of
it but this depends on your needs.

I have a Novy accellerator and am extremely happy with it. Speedometer
rates my 20MHz 68020 processor at about the same speed as the Mac IIcx
in all areas except disk I/O which is about .5 instead of 1.5. In all
cases it is at least double the speed of a Classic II (except disk
I/O). Novy tech support is good; I actually got to talk to one of
the techs and/or an engineer - much better than simply somebody who
answers the phone and asks your questions for you.

Here are a few things to check out when looking for an accellerator.
Some of this is from first hand experience and some of it came from
the tech support people at the various companies I called.

1) The most important thing to check for is that the power supply in
your Mac Plus or 512Ke is in good condition. If you have a marginal
power supply then the accellerator may draw enough energy to make the
entire machine crash randomly; it may also 'restart' at unexpected
times. If you are unsure about your power supply or want to 'beef up'
your power supply board then check with Soft Solutions; they have a
power supply upgrade parts kit for about $50. There may be other
companies doing this too - Soft Solutions is only one option. You also
want a fan - a nice quiet one is great for the nerves. The fan will
help your accellerated Mac keep it's cool.

2) Ensure that the accellerator solders onto the motherboard somehow.
I have installed a number of 'clip-on' devices for other people and
they simply are not as reliable. I found the machines had odd crashes
with strange errors, at unpredictable times. The Novy board is
installed by a socket which is soldered to the 68000. The accellerator
then plugs into the socket. If you are not confident with a soldering
iron or you lack a good grounded/isolated tip soldering iron then
leave the instalation of the accellerator for the techs; it may cost
you $50 to get installed but this is much cheaper than a new motherboard.

3) Check that there is some way to boot up your Macintosh without the
accellerator. You may need to do this for some incompatible software.
In my experinence this is rare - I have only needed the option when
running hardware diagnostics on the motherboard. It's still nice to
know that you don't have to disassemble your Macintosh to turn off the
accellerator. Another reason is to play a game that just became
impossible with the faster Macintosh; being able to reboot without the
accellerator is a useful even though seldom used feature.

4) Make sure that the accellerator does not require an INIT or something
to run before it is functional. The board should look as transparent
to the hardware and operating system as possible. Some accellerators
don't even work unless an init runs first. This may limit your options
for future Apple system software. When I purchased my Novy board,
Multi-Finder was fairly new on the scene. Today, it works without a
hitch with System 7.0 - software that wasn't talked about when the Novy
board was designed. All accellerators I have seen come with software to
make it work better but I wouldn't recommend purchasing an accellerator
that will not work without the software.

5) For best performance, make sure that any memory installed in the Mac
can be put on the accellerator; you want 32 bit memory access and the
motherboard cannot give you this. Some accellerators simply give you a
faster 32 bit processor and drive the memory accesses through a 16 bit
bus; this is faster but you give up about 50% of the potential gain.
In the case of the Novy, you can put 4M on the accellerator and
turn the 1M of ram on the motherboard into a ram disk or disk cache.
In some cases you simply use what is on the accellerator and ignore
the ram on the motherboard. In other cases you cannot put any memory
on the accellerator.

6) Many accellerators allow for a 68881 or 68882 floating point
processor. If you don't do much heavy calculation then don't spend
the extra money on an FPU. They are an expensive option that few
people gain much speed from. This however is not always the case.
For those who need the FPU the performance increase can be dramatic.
I have a 68882. It wasn't worth it for the kind of things I do; examine
carefully what applications you use most - are they math intensive?
Also note that the 68881 and 68882 are pin compatible - the 68882 is
about double the speed of the 68881 and is well worth the expense if
you really need an FPU.

7) Most accellerators on the market provide a SCSI port as an "option".
It is usually not much more money and is definately worth it. The
MacPlus SCSI port is slow - I guess this comes from being the first
SCSI port? The accellerator will use the faster SCSI giving you
potentially 4 or 5 times the disk access speed. I didn't think this
was worth the extra $50 when I purchased my accellerator. I regret
that decision now. This is of course not an option for 512Ke owners,
you need the SCSI port for a hard disk.

8) These days, get an 030 based accellerator if you can afford it. The
memory management unit of the 68030 allows you to use packages like
Virtual. You can then have more than 4M of useable ram through VM.
The 68030 based accellerators are normally a bit more expensive (the
cpu costs more) but the extra potential (> 4M RAM) and speed are worth it.

9) Some accellerators do not work with certain hard disk units - check
with the vendor of the accellerator and the hard disk to see what they
say. The problem is usually drivers that make assumptions that aren't
true when an accellerator is installed; you could wind up with a fast
Mac that won't talk to your hard disk. Today this is not as much of a
problem as it used to be; when I bought my Novy board the Mac II was
new on the market and most hard disk vendors didn't expect to have a
fast Mac to work with. It still doesn't hurt to check, it could save
you a lot of grief.

Finally, after you have your unit installed you will see a few
differences. The most obvious is the speed - things are much snappier
but that's what you bought the accellerator for. Unfortunately, there
seems to be a down side too. Many manufacturers claim that the software
that comes with the accellerator will fix the garbled sound that you
get from your "sys beep" collection. This just isn't so. I have used 3
different accellerators (Novy, Radius, and NewLife) and all claim to
have fixes for the sound - none of them work with the latest incarnation
of the sound manager from Apple (ie System 6.0.7 or System 7.0). That's
life in the accellerated Mac lane and there is not much I am aware of
that you can do. Other than the sound, everything else seems to be okay
in my experience. It is also possible that you won't have any sound
problems with a 68030 accellerator; I don't have one to compare so I
cannot tell you.

-- 
Dave Milton, University of Manitoba, Winnipeg, Canada. (204)788-6346
Internet: <milton@ccu.UManitoba.CA>  Bitnet: <milton@UOFMCC>