I keep looking at the problem, along with some of the comments you've made, and I keep reaching for the "looks like homework" tag.

From where I sit, I see these possibilities:


1. Homework assignment, with assigned parts. Possibly being led by an instructor with incomplete or outdated training. This happened to me in high school, but I can't see it happening in a college setting.


2. Ambitious high school student with a tight budget and/or no credit card. Been there done that! Thank God I grew up near NorthStar, Godbout, and Mike Quinn's.


3. ???


Not even a semi accomplished amateur is going to bother trying to do what you're trying to do. It just doesn't make sense. I even sent you a link to plans for a eprom emulator that basically does exactly what you want to do. I just can't come up with a valid reason why someone would want to go to all this trouble just to avoid buying a $2 chip. I have to conclude that a $2 purchase is impossible for one reason or another, and that you have not been entirely forthcoming in your descriptions.


Time to fess up Mike. Are you doing homework for an acredited school? Are you simply a very ambitious high school student? It's OK to be the latter! Virtually every one of us was there at one time or another. But please, no more blather about "guts to try". Guts is for charging into machine gun fire. We're engineers, we look up the machine gun's specs and build something with longer range.