PDP-11 Extended Instruction Set
From Computer History Wiki
The Extended Instruction Set is an extension to the basic PDP-11 instruction set; it includes hardware multiply and divide, and also multi-bit shifts. The exact instructions included in the EIS are:
- MUL
- DIV
- ASH
- ASHC
It was not available on the earliest PDP-11 models (the PDP-11/20 and the PDP-11/05), and the later PDP-11/04; it was available as an option for the PDP-11/40 and the PDP-11/03; it was standard on all other PDP-11 models.