I want to realize a combinational logic function that can perform the function of a 74*381 by using a particular size of a ROM. Could anyone tell me what kind of ROM should I use?

 

ROM = Read only memory (?)

How would some ROM realise a logic function?

 

A number in brings a number out. A truth table in other words. Old tech, but it works well.

 

A 74381 is a ALU (arithmetic logic unit). It has 12 inputs and 6 outputs. That means it has 2^12 bits X 6, or 4,096 X 6 cells. Seems doable, but a real pain to program.

 

Does each ROM need one output or six outputs?

 

I'm thinking there are 4K X 8 ROMs out there, but more than that I can not help with. The X 8 is the data width of a 8 bit word. You are going to also need an EPROM programmer.

 

Hello,

Bill is right. An 2732 eprom would work.
http://www.futurlec.com/Memory/2732A-200.shtml

They are not realy fast but they will work.
On the shown page you can aslo download the datasheet.
You will need a promprogrammer to put the data in the chip.

Bertus