| 摘要 |
979, 816. Address selection;coding. INTERNATIONAL BUSINESS MACHINES CORPORATION. Sept. 20,1961 [Sept. 21, 1960, No. 33717/61. Headings G4C and G4H. A five-digit binary coded (1-2-4-8) decimal number is used to represent one out of 1600 fourteen-bit combinations for the purpose e.g. of address selection. The 8-bit of the tens of thousands order is not used and the 1-, 2-, and 4-bit positions of a decimal register 10 are connected to orders 0 to 2 of a binary register 15, thus giving eight combinations. The 1-bit positions of the thousands, hundreds, and tens orders of the decimal register are connected to orders 3 to 5 of the binary register, also giving eight combinations. The or circuits 11 and 13 and and circuit 12 connected to the bit positions of the units order of the decimal register enter a one if the units decimal is five or more, a zero otherwise, into order 6 of the binary register, giving a further two combinations. In the tens, hundreds and thousands orders of the decimal register, each set of 2-, 4- and 8- bits can form five combinations, and a translator 20, comprising and and or circuits (Fig. 4 not shown), produces a binary representation in orders 7 to 13 of the binary register of that one of the 125 possible combinations formed by the nine inputs from the decimal register. |
