uh1021 <ulrich.hausmann@a2e.hp.shuttle.de> writres:

>Does anyone know here by chance
>
>a) where to get full 68040 processors for cheap

The best sources for cheap '040's are generally vendors that do repairs or
deal in used/refurbished equipment.  I would suggest picking up a computer
margazine -- look through the classifieds.  Make calls.  Send E-mails.

Perhaps I should qualify my repsonse.  I've found that to be the case in
the US, but I see you're in Germany.

>b) whether or not a 33 Mhz processor would also work in a 25 Mhz machine
>(like C 610 or Q 605 or LC 475)?

Yes.  But you'll need to chip the machine up to 33 mhz.  Otherwise it will
continue to run at 25.


>c) if a 25 Mhz processor in 33 Mhz machine would break because
>overclocked?

I talked with a number of vendors when I took this plunge a few years.  I
have a Q605, with FPU, chipped to 33 mHz.  They all said the same things:

>From what I understand, the LC040 chips really don't care. You can
overclock a 68LC040 and it 'will usually do just fine'.

For the full 040's  (w/ FPU) this is NOT true.  Vendor consensus -- Trying
to overclock the FPU tends to make the chips 'extremely unstable'.  (I
don't like the sound of that).  However, the FPU's don't mind being
underclocked.

Say your get a 33 mHz 68RC040 (that's the model number for the one with the
FPU).  If should be fine whether run at 25 mHz or 33 mHz.  I ran my 33 mHz
chip at 25 mhz for about a month before getting the clock chipper -- no
problems.

However, in the case of a 25 mHz 68RC040, you're stuck at 25 mHz.  Trying
to nudge it up to 33 will most likely make both you and the machine very
unhappy.

Good luck.

Steve Revilak
revilak@umbsky.cc.umb.edu