[comp.sys.mac.misc] Accelerators for MAC

rgp@deth.westford.ccur.com (Dick Phillips) (08/17/90)

So, I ask this question: Can I expect solidly reliable
operation with a 50 Mhz accelerator?

A second question has to do with MAC accelerators in general.
Suppose I have one installed.  Then let us further suppose that
at some later time, doing
some particular thing, I may wish to operate WITHOUT it.  Can
I just unplug it from the CPU chip and turn the machine back
on or would it mean extensive wiring changes?

Any replies will of course be appreciated.

			Dick Phillips (day phone: 508-392-2965 E.S.T.)

gt4586c@prism.gatech.EDU (WILLETT,THOMAS CARTER) (08/18/90)

In article <45992@masscomp.ccur.com>, rgp@deth.westford.ccur.com (Dick Phillips) writes:
> So, I ask this question: Can I expect solidly reliable
> operation with a 50 Mhz accelerator?
> 
> A second question has to do with MAC accelerators in general.
> Suppose I have one installed.  Then let us further suppose that
> at some later time, doing
> some particular thing, I may wish to operate WITHOUT it.  Can
> I just unplug it from the CPU chip and turn the machine back
> on or would it mean extensive wiring changes?
> 
> Any replies will of course be appreciated.
> 
> 			Dick Phillips (day phone: 508-392-2965 E.S.T.)

I had a Radius 16 Accelerator in my SE (until i sold it and got a IIci).
It is a 16MHz 68020 accelerator with 68881 socket.  It came with an init
that provided a software switch to turn it off - you just held down the
mouse button during startup and the Radius control panel popped up to 
allow you to turn it off it yuu wished.  It would then restart the machine
without the accelerator.

In a more general vein, my experience with the Radius had a few hitches.
Even though I had the 68881 math coprocessor installed, for some reason
I couldn't run MatLab with the accelerator.  However, Mathematica worked
fine.  Also, I was writing my own fast fourier program in pascal, and
sometimes when I ran it the accelerator would sometimes appear to get
turned off.  Even stranger, if I just left the machine alone for a while
it would seem to start itself again.  These weirdnesses convinced me not
to much around with accelerators and get a mac II.


-- 
thomas willett 
Georgia Institute of Technology, Atlanta  
gt4586c@prism.gatech.edu
"Violence is the last refuge of the incompetent." - Salvor Hardin (Foundation)