Author: William R. Myers

Aerojet Nuclear Company, Idaho Falls, ID

Operating System: Paper Tape

Source Language: PAL-III

Memory Required: 1249 words

Abstract: FP8 is a floating point arithmetic interpretive program for use in any DEC PDP-8 series computer. It is somewhat smaller and much more versatile than the standard arithmetic package supplied by DEC. The full program requires 1249 locations in one memory field (plus 5 to 34 locations in remote fields, for linkage) compared to the 1408 locations required by the DEC software. FP8 implements access across field boundaries for both instruction sequences and operand reference. A four-bit operation code is used to obtain an expanded set of floating-mode instructions including: add, subtract, multiply, divide, inverse divide, load, store, three-way compare, and jump and jump-to-subroutine. Operate- class instructions include: single- and double- precision fix and float operations, and square, square root, exponential, logarithm, sine, cosine, and arctangent functions, and free-format input and variable-format output routines. The program size may be reduced to 663 locations by deletion of the function and input/ output routines.