[sci.electronics] 68000 Chips

rzh@lll-lcc.llnl.gov (Roger Hanscom) (12/07/88)

In item <12169@cup.portal.com> Jeff_A_Scott@cup.portal.com
writes:

>I'm looking for a low-priced source of Motorola 68020 processors.
>I just want one (and a 68881 co-processor) and I've looked in all the
>common places (back pages of Byte, etc).  Since this is a ~$300 purchase
>the best price is important.  Anyone know a cheap place?

  If you can lower your sights a little, a 10 MHz 68010 can be had
rather cheaply -- say about $10 at computer shows, etc.  Co-processors?
You're on your own ..... probably big $$$.

dya@unccvax.UUCP (York David Anthony @ WKTD, Wilmington, NC) (12/07/88)

In article <2196@lll-lcc.llnl.gov>, rzh@lll-lcc.llnl.gov (Roger Hanscom) writes:
> 
> In item <12169@cup.portal.com> Jeff_A_Scott@cup.portal.com
> writes:
> 
> >I'm looking for a low-priced source of Motorola 68020 processors.
> >I just want one (and a 68881 co-processor) and I've looked in all the
> >common places (back pages of Byte, etc).  Since this is a ~$300 purchase
> >the best price is important.  Anyone know a cheap place?

	If you are on good terms with your local Schweber or Hamilton-Avnet
rep (or other Motorola distributor) they should be able to secure a 12.0 
mHz processor in the $80-$120 range.  They are jellybean parts now.  (I
think I paid $135 for MC68020RC12 last summer, which is still awaiting the
breadboard!).

	For the coprocessor, you are on your own.
	Try and get prime parts, anyway.  I can't believe that most of the
junk in the back of consumer fishwrappers were obtained from legitimate
sources.  (We've bought some, er, grey-market RAM chips from ads in
magazines (they take MC &Visa, hey, what can I say) and while they meet
the speed spec, they usually do not meet the speed at power dissipation
spec.)
	
	68008's from a **well known** mail order place (Mostek brand) have
an off-spec failure of about 1 part in 25.  DUARTS (MC68681) were even
**worse**.

	If at all possible, get prime parts.  Saving money on off-spec
devices, fallouts, cull-outs, call 'em what you will, is false economy.

York David ANthony
WKTD Wilmington, NC

neals@tekigm2.TEK.COM (Neal Sedell) (12/13/88)

Y.D.AN. writes:
>	If you are on good terms with your local Schweber or Hamilton-Avnet
>rep (or other Motorola distributor) they should be able to secure a 12.0 
>mHz processor in the $80-$120 range.

- and then he says -

>	If at all possible, get prime parts.  Saving money on off-spec
>devices, fallouts, cull-outs, call 'em what you will, is false economy.
>

Gee, if the 68020RC12 wasn't an off-spec part it would run at a maximum
clock freq of 12.5MHz, not 12.0...  Same thing for the 'RC16 - max clock
is 16.7MHz (actually the minimum clock period is 60ns....)

Seriously, watch out for the minimum frequency too - it's 8MHz for both
the '12 and the '16.

Good luck finding a cheap co-processor - supply/demand/production volume/
yield/etc. isn't on the consumer's side at this point.
-- 
Neal Sedell