Archive for February, 2009

February 2nd, 2009 ~ by admin

Rare CPU Find of the Day: National Semiconductor IMP16A-500D

Back in the day of CPU’s National was on the forefront of CPU design, while Intel was messing around with 4 and 8 bit designs.  It by itself was the 4th CPU, and the 1st bit slice device. 

It consists of:
4 x 4 bit IMP-00A/520D – These are the Register and Arithmetic Units
1 x IMP16A-521D – Standard 16 bit Instruction set control chip (Based on the Data General Nova)
1 x IMP16A-522D – Extended 16 bit Instruction set (not sure what addition instructions it has)
These were sold in a set by National, and in a pretty nice box.

National IMP16A-500D

National IMP16A-500D

Later on National implemented them as a single chip, the IMP16A-500D PACE, and then the NMOS INS8900.
More infomation about the IMP16 can be found at Antique Tech