Hi PICsters,


If anyone has a PIC application that requires more speed and density that
typical EEPROM storage solutuions, I have developed a low-cost (<$12) FLASH
storage solution.  It uses some simple 8-bit latches, one buffer, and 8 I/O
lines off a PIC16CXX.  I have it running with a PIC16C74 @ 20MHz.  I also
used all 74HCxxx parts and 29C010 FLASH devices for low power consumption.

This solution is many times faster than serial EEPROMs.  The PIC makes an
excellent state machine also.  Like a super PAL.  I have state machines I
did with MPASM if anyone is interested.  These FLASH devices are +5v
programmable in-circuit.  The Flash File system writes 128 bytes per sector
into the FLASH chip, and "objects" can be linked with a absolute sector
address.  So the text string "bong.snd" would be looked-up in a simple
directory, and the sector address and file size would be known.   I also
use part of the PIC16C74's internel registers as a "disk cache".

I also have some other info on the high-density SRAM interface that works
just like the FLASH interface, at http://www.webo.com/picbot


My application required rugged, solid-state storage of data objects.  The
FLASH storage system exceeded spec, and offered a performance boost by
moving 8-bits in parallel in/out of the PIC microcontroller.


Claude Wright