Double Precision Binary Coded Decimal Arithmetic Package
8-100

Richard M. Merrill, Digital Equipment Corporation, Maynard,
Massachusetts

Consists of the following routines:

BCDADD - The single precision BCD addition routine is the
basic component of the BCD arithmetic package. This
routine functions simply by masking out and adding together
corresponding BCD digits (i. e., four bits) and checking for
carry (i. e., when the sum of two four-bit numbers is greater
than 9 (1001)).

MPYBCD - This routine multiplies a single precision (three
digit) number times a double precision one to produce another
double precision number. Overflow is indicated in the link;
the arguments are not affected.

SUBBCD - One double precision BCD number is subtracted
from a second by this routine. It uses a 9's complement
routine and the double precision add routine.

DOLOUT - Special formats: ("$XXXX.YY ").
("XXXXXX "); (3 nonprinting data codes); ("XXX ").

Catalog:November 1969