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DoctorWkt / CSCvon8

A crazy small 8-bit CPU built with only seventeen 7400-series chips.
GNU General Public License v3.0
104 stars 13 forks source link

Suggestions for EEPROM/FLASH ALU? #2

Open johnterickson opened 4 years ago

johnterickson commented 4 years ago

First off, wow! This is really cool! I am both excited to find this, but also a little bit bummed out that my idea of "use a big honking ROM LUT as the ALU" is not novel 😁 https://github.com/johnterickson/lutcomp/tree/master/acc

Anyway, I noticed that the ALU is not eraseable. Any suggestions for one that is? The biggest parallel-out, 5V, through-hole chip I've found is the SST39SF040-70-4C-PHE which is only 2Mb.

I was looking at AS29CF160B-55TIN which is 32Mb. This is TSOP, but I was thinking I could get a breakout board and still essentially have a breadboard computer.

DoctorWkt commented 4 years ago

Hi John. Well the M27C322 is writeable, you just need a UV eraser and a MiniPro EPROM programmer :-) That AS29CF160B looks nice but it's only 1Mx16, so after the two 8-bit data inputs you only get either sixteen ALU operations, or eight if you need a Carry in. I've been looking for a SMD replacement for the M27C322 but I haven't found one yet.

There's a private TTLers forum on Hackaday.io. If you search for Yann Guidon, send him a PM and let him know I sent you; he can add you to the forum.

I'm currently working on the next CPU, https://github.com/DoctorWkt/2FISC Cheers, Warren