| 摘要 |
1277181 Counting and complementing numbers INTERNATIONAL BUSINESS MACHINES CORP 12 Jan 1970 [30 April 1969] 1360/70 Heading G4A A binary register system comprises a plurality of bi-stables 11, 12, 13, 14, storing a binary number, connected in cascade through a logical control circuit having a first input terminal P1 which, when energized, applies a signal to the inputs of all the bi-stables to ones-complement the number, and a second input terminal P2 which, when energized, applies a signal to selected ones of the bi-stables to twos-complement the number. If the terminals are energized alternately, the register counts up or down according as (starting from 0000) P1 or P2 is energized first, respectively. The bi-stables may be preset (by means not shown) with any required number. |
