FP780 Floating-Point Accelerator

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The FP780 Floating-Point Accelerator was an optional floating point accelerator for the VAX-11/780's KA780 CPU; the floating point instructions were performed by the microcode when it was not installed. It was installed in slots 24 through 28 of the CPU's backplane.

Implementation

It was implemented on five hex cards:

Slot Board Acronym Function
24 M8285 FNM Normalization and fraction division
25 M8286 FMH Fraction multiplication (most significant bits)
26 M8287 FML Fraction multiplication (least significant bits)
27 M8288 FAD Fraction addition and subtraction
28 M8289 FCT Exponent manipulation and FPA control

External links