Boots – shoes – and leggings
Patent
1987-01-12
1988-05-03
Buczinski, Stephen C.
Boots, shoes, and leggings
364771, G06F 100, G05F 750
Patent
active
H00004723
ABSTRACT:
A system (FIG. 1; FIGS. 18-19) performs addition or subtraction of packed, or binary-coded-decimal (BCD), values. Each BCD digit is stored in a nibble (500) of a register (400, 401). The least-significant bits (LSBs) (502) of corresponding nibbles of the registers are exclusive-ORed and results are stored in a third register (402) (FIG. 4 or 9). For addition, the registers' binary values are summed, six is added to each nibble of the sum using binary addition, and results are stored in one register (401) (FIG. 5). For subtraction, the registers' binary values are subtracted, and the results are stored in one register (401) (FIG. 10). The LSB of each nibble of the one register is compared with the corresponding exclusive-OR value from the third register (FIGS. 6 or 11). For every comparison that indicates equality for addition, and that indicates inequality for subtraction, six is subtracted using binary subtraction from the value of the one register's nibble that precedes the compared values' corresponding nibble in the registers (FIGS. 6-7 or 11-12).
REFERENCES:
patent: 3937941 (1976-02-01), Zemel et al.
R. Zaks, Programming the Z80 (Sybex, 1982) pp. 107-113, 236-237.
J. A. Otto, "Predicting Potential COBOL Performance on Low Level Machine Architectures," SIGPLAN Notices, V. 20, No. 10 (Oct. 1985) pp. 72-78.
R. K. Richards, Arithmetic Operations in Digital Computers (D. Van Nostrand Co. 1955), pp. 209-285.
G. Chroust, "Method of Adding Decimal Numbers by Means of Binary Arithmetic", IBM Technical Disclosure Bulletin, V. 23, No. 10 (3-81).
D. R. Hicks et al., "Multidigit Decimal Addition and Subtraction", IBM Technical Disclosure Bulletin, V. 19, No. 11 (4-77).
Buczinski Stephen C.
Wallace Linda J.
LandOfFree
Method and apparatus for processing binary-coded/packed decimal does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for processing binary-coded/packed decimal , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for processing binary-coded/packed decimal will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1497545