Re: ********

[dempson@actrix.gen.nz (David Empson)]

In article <3297ku$hoe@manuel.anu.edu.au>,
Stuart David Midgley <stu@aerodec.anu.edu.au> wrote:
> 
> 	I read in the news the other day, about the new 14MHz 65c816
> chips from WDC.  I would really like to get two of them.  How should I
> go about this?  I know that I need to contact someone on "online" but I
> have no access to this (I dont think).  Can anyone help me get these?
> I live in Australia, so what will be the deal?   

[A suggestion: try pressing RETURN every 70 columns or so]

I suggest you try to find several like-minded people in Australia, and
arrange for a single large order with WDC.  I'm planning to do this
for myself and a couple of friends in Wellington.

I haven't contacted them yet regarding minimum quantities or any other
problems that may crop up with international orders.  When I do, I'll
post here with any relevant details.

> 	I have a 10Mhz zip, with 64k cache (20ns).  Do I need anything
> to make the faster chipe run, other than a faster crystal? 

You can't go past 12 MHz unless you modify the card (some circuitry in
the ASIC has a bottleneck at about 12.5 MHz and needs to be bypassed).
I don't have the details for this.

You may need to increase the speed of your cache RAM.  According to my
(probably naive) calculations, 20 ns should be sufficient for anything
up to 20 MHz.

Locating high-speed crystal oscillators may be difficult.  I haven't
been able to source anything faster than 40 MHz in New Zealand.  (To
run at 12 MHz, you'd need a 48 MHz oscillator.  To run at 14 MHz,
you'd need 56 MHz.)


In a ROM 1, the machine may be too noisy to work reliably beyond 10
MHz.  A ROM 3 may also top out at some point, depending on what cards
you have in the computer.
-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand