FP11-B Floating-Point Processor
From Computer History Wiki
The FP11-B was a FPP used in the PDP-11/45 and PDP-11/70 computers (KB11-A and KB11-B CPU variants thereof, respectively); it was the progenitor of the semi-standard FP11 floating point used in many PDP-11s.
It operated in parallel with the main processor, so that two instructions (one floating point, one regular) could be processed at the same time; unlike the later FP11-C Floating-Point Processor for these machines, it ran entirely asynchronously to the main CPU, and used a clock which was not synchronized to the basic CPU's clock.
Implementation
It plugged into special pre-wired slots in the CPU's backplane, and included the following boards:
- M8112 ROM and ROM Control
- M8113 Exponent and Data Path
- M8114 Fraction Data Path - High Order
- M8115 Fraction Data Path - Low Order