[comp.sys.mac.hardware] 68EC030 and 68030

KPURCELL@LIVERPOOL.AC.UK (05/08/91)

On the standard Mobius '030 accelerator and full page display a 68EC030
is used rather than a 68030 and consequently you can't use Virtual
to gain virtual memory (so Mobius says).

Is the EC a "crippled" 030 (minus the onboard MMU)? Is it pin compatible
with the 030?

Mobius offer an upgrade (which from what I can gather is just a replacemnt
of the EC030 with a real 030) for $250. They charge a similar amount for
adding an FPU (which you can do for $60 less yourself).

Anybody know? Anybody got the datasheets.

E-mail me or post here if you think others may be interested.

Kevin

amanda@visix.com (Amanda Walker) (05/10/91)

KPURCELL@LIVERPOOL.AC.UK writes:

   Is the EC a "crippled" 030 (minus the onboard MMU)? Is it pin compatible
   with the 030?

Yes to both.

I haven't seen a data sheet yet, but I suspect that 68EC030 chips are made
from 68030 dies which have defects in only the MMU portion.  By trimming
out the defective MMU, they still have a perfectly good processor that is
better than an equivalent 68020, thus increasing the effective manufacturing
yield.

Pretty clever idea, actually.

--
Amanda Walker						      amanda@visix.com
Visix Software Inc.					...!uunet!visix!amanda
-- 
"We are continually faced with a series of great opportunities brilliantly
 disguised as insoluble problems."	--John W. Gardner