As a practical matter, the code offered below only works with the Microwire 3 Wire interface, and is specifically intended to work with the 93C46, which is a standard part available from a variety of distributors. It can be used without much difficulty with a 93C46, by avoiding calls to the routines that manipulate the extended features of the 93CS46. They have also added example 8051 code similar to the code below, as well as for I 2 C parts they offer. National Semiconductor has lots of data sheets on-line. I used their 93CS46 data sheet to write the code.
MicroChip now has data sheets on-line for most of their products.
SGS Thompson made the chips I used when I wrote this code. I used the National datasheet to write the code, but the SGS Thompson parts worked flawlessly. They offer quite a few different types of serial eeproms, including of course the 93CS46 and 93C46. Xicor has quite a bit of example code on-line, including code for the 8051 family. What this 8051 family code does This code was written to support the 93CS46.