> If you do not have to access the data very fast you could also "expand"
> the number of I/O lines by adding serial-parallel shift registers to
> use as the address lines for the memory. This would let you use just 2
> or 3 pins on the PIC to create 8, 16, 24, ...? address lines as needed.
> The penalty is you have to shift the address out to the memory before
> each read or write. This is a useful technique for using any micro in
> apps that need lots of digital I/O when extreme speed is not required.

Yeah, I've chosen to use latches on a semi-bus-based system.  Good idea
though, I think that the latches will be faster.  I can use 8-bits as a
my bus and then use the other pins for selecting latches and doing misc.
control functions to some of the chips.

--

            -- Paul Greenwood --  (pablo@austin.ibm.com)

Any small object that is accidentally dropped will hide under a
larger object.