Microcontroller parallel eprom emulator?

In need to make a purpose built emulator for a 27c128, not exactly a "full blown" emulator, but one that can alter a relatively small(less than 256) amount of specific addresses in an allowable amount of time(~100ns).My microcontroller experience is limited to PICs, which I can write code for easily,but even at 40mhz won't do the job fast enough.Any suggestions or advice? Any specific micro/architecture I should have a look at?

A CPLD is perfect for this type of job. Xilinx and Altera both have cheap CPLDs and free software for develpoment. CPLDs are programmable logic devices - you program in the logic gates, flipflops etc. that you need. Most devices claim better than 10ns pin to pin delays. You can get a decent CPLD for $2 to $5.

Brent