[comp.sys.mac.hardware] Mac II Accelerators

daemon@bloom-beacon.MIT.EDU (Mr Background) (10/27/89)

From: mhamaoka@athena.mit.edu (Michael T Hamaoka)
Path: athena.mit.edu!mhamaoka

Hi,

   Our office is thinking of getting an accelerator card for
our Mac II and I would like to ask you netters for some advice.
We currently have our eyes on the Daystar Digital Accelerator II.

   Has anyone out there had any experience with this card?  Is
it a good product?  If not, can you suggest other accelerator
which would be better?

   Thanks in advance for the help.

   --> Mike

brando@mitre.org (Thom Brando) (11/07/89)

>>    Has anyone out there had any experience with [the Daystar Digital
>> Accelerator II]?  Is it a good product?  If not, can you suggest other
>> accelerator which would be better?

I just put a 40-MHz Accelerator II in my Mac II recently and have been very
pleased (so far :-).  I haven't found anything that runs on an SE/30 that
doesn't run on the accelerator board.  (This means I've been able to run
MacWrite II, MacDraw II 1.1, MacTerminal 2.3, Microsoft Word 4.0, PageMaker
3.02, Illustrator 1.8.3, Freehand 2.0, Allegro CL 1.2.2, and Smalltalk-80 v2.5
(some more extensively than others, of course :-).  I also use QuickMail 2.01,
Master Juggler 1.50, and MacroMaker 1.0.1.)

As far as speed in concerned... I expected the 40-MHz accelerator to
outperform a 16-MHz SE/30 by a factor of 2.5.  We ran an assortment of timing
tests using Allegro CL, and got execution times that were faster by almost
exactly a factor of 2.  So where did the other .5 go to?  Well...
unfortunately, the installation manual I got with the accelerator didn't say
anything about this extra little jiggy that came with the accelerator, so the
jiggy never got installed.  I spoke with Daystar later and found out that the
jiggy is their own PMMU which is supposed to replace Apple's AMMU and thereby
eliminate a wait state that's incurred for every memory access that goes
through the MMU.  I have yet to install the jiggy, but when I do, I'll run my
timing tests again and see what happens.  Also, I believe the 50-MHz board is
now available, and I'm waiting for my free upgrade... yummmm!

--
Thom Brando                                       (617) 271-3947
The MITRE Corporation, m/s A129                 brando@mitre.org
Burlington Road, Bedford, MA 01730              ...!linus!brando