KE11-B Extended Arithmetic Element

The KE11-B Extended Arithmetic Element is a program compatible re-implementation (on a single hex board - the M7840) of the KE11-A Extended Arithmetic Element, an autonomous UNIBUS peripheral which can perform a variety of arithmetic or logical operations:

• multiplication
• division
• multi-bit shifts
  • logical shift
  • arithmetic shift
  • normalization

(The last is used for implementation of floating point in software.)

The original KE11-A was produced for use with the PDP-11/20, whose KA11 CPU did not have multply, divide, or multi-bit shift operations. As a UNIBUS peripheral, not integrated into the CPU, it was also usable with other models, e.g. the PDP-11/05 and PDP-11/04, which likewise did not implement multiplication in hardware, etc. The KE11-B can be used with these later models.