RE: Putting a RAM chip in U36 on a C128
Date: 2002-08-22 09:27:40

Hi all,

-----Original Message-----
> ST> selected. If the CS is not generated on write, the R/W logic is
> Ah, major gotcha. Yep, doesn't work, back to the drawing board :)
>anyway, why not generate the CS on our own? We can CS when we get a

I've used a 74138 to decode 8k chunks allow writing to external RAM at
$8000. During "writes" both the internal and external RAM get written to
though! The external RAM's CS needs to be ORed with the ROM-select to ensure
it then responds as a "ROM". A switch (mechanical or electronic) can be used
to disable writes.

- Nick


The contents of this email (including any attachments) may be
privileged and confidential. Any unauthorised use of the contents
is expressly prohibited. If you have received this email in error,
please advise us immediately (you can contact us by telephone
on +61 8 9441 2311 by reverse charge) and then permanently
delete this email together with any attachments. We appreciate
your co-operation.

Whilst Orbital endeavours to take reasonable care to ensure
that this email and any attachments are free from viruses or other
defects, Orbital does not represent or warrant that such is explicitly
the case

(C) 2000: Orbital Engine Company (Australia) PTY LTD and its

       Message was sent through the cbm-hackers mailing list

Archive generated by hypermail 2.1.4.