Re: Quantum processor speed?

tom mcclintock wrote:
>
> I've got a Quantum board that has a MC68000C8 processor - presumably an
> 8MHz chip, right? So there is another board with a MC68000P10 processor
> on it (again, this is a 10MHz chip, correct?).

Yes - You're right about this.
 
> I'm curious to know if the crystal on the board determines the speed of
> the CPU, or does it matter what speed 68000 CPU is used, just as long as
> its a 68000? And what is the correct speed then? There seems to be quite
> a price difference (well, relative difference) in price between the
> faster and slower CPUs.

It is the crystal chip determining the speed of the processor. So if you plug in
this expensive 10 MHz version, it will make absolutely no differecne, since it
is still running at 8 MHz. The speed indication on the uP is jsut the maximum
speed it can run at (well, that is what the manufacterer wants to make us
believe, but that is another story).

Anyway, you cannot just place another chrystal on the board, since the crystal
is not only determining the uP speed, but also, in most cases, determines
clocking speed of a lot of other components, such as RAM timing, Vector
generation ect ect.

Cya !
---------------------------------------------------------------------------
** To UNSUBSCRIBE from vectorlist, send a message with "UNSUBSCRIBE" in the
** message body to vectorlist-request@synthcom.com. Please direct other
** questions, comments, or problems to neil@synthcom.com.
Received on Thu Jul 13 12:49:33 2000