I have hooked a Dallas 2MB NVRAM to a 16C77 using cascaded 595's for the
address and an 8 bit data bus.  If I remember right, I used the extra
outputs on the 595's for the control lines on the NVRAM. Didn't test it
much but it worked.

Eric

On Wednesday, July 21, 1999 11:44 PM, Thomas Brandon
[SMTP:tom@PSY.UNSW.EDU.AU] wrote:
> Microchip has an application note on attaching SRAM to a PIC16CXX
(TB011).
> This application note shows a circuit in which 2x256K(32Kx8) chips are
> hooked up using a 16-bit address bus multiplexed with an 8-bit data bus
> (total of 19 pins).
>
> There is also an application note on connecting external memory to a
> PIC17xxx via it's inbuilt bus (TB005).
>
> The opnly limitation is the size of address bus you can manage. Obviously
> you can get a very large bus with lots of multiplexing but this adds
> components and complexity (both to circuit and to code). I'm also not
sure
> about whether timing would become an issue with more chips.
>
> However, it is certainly possible to hook up at least 256K to almost any
PIC
> with an efficient use of pins.
>
> Hope that helps,
> Tom.
> ----- Original Message -----
> From: Brian Gracia <bgracia@RTRIPP.COM>
> To: <PICLIST@MITVMA.MIT.EDU>
> Sent: Thursday, July 22, 1999 2:08 PM
> Subject: SIMM Memory and Pics
>