| 摘要 |
1,081,199. Digital conversions. INTERNATIONAL BUSINESS MACHINES CORPORATION. Nov. 3, 1965 [Dec. 23, 1964], No. 46490/65. Heading G4H. A code converter involves repetitive modification of a character. A multiplexor 16 which selects input lines in turn, receives a multi-bit character from a selected input line 17 and passes it directly or via a decrementer 27 to a character register 25 from which it is reinserted (" regenerated ") into the same input line 17. A delay-line-loop memory 10 stores the possible characters of various codes, one code for each input line 17, two successive characters of a given code being separated by a character of each other code. The system deals in a time-divisionmultiplex manner with the input lines 17, successive uses of the character register 25 &c. in connection with one input line 17 being separated by such a use in connection with each of the other input lines 17. An input character is preceded by a special bit indicating that conversion is required. The first character of the sequence of characters for a given code, in the memory 10, is set to 1 in its first bit position which thus constitutes a start-oftranslation (SOT) tag. Forward conversion.-The input character is passed to the character register 25, and regenerated therein via the decrementer 27 (starting at the detection of the SOT tag at the memory 10 output) until the character register 25 contains all 1's when the current output of the memory 10 is gated 14 to the system output (and may be reinserted without decrementing until it is required). Backward conversion.-The input character is passed to the character register 25 and regenerated therein without decrementing until it is equal 15 to the output of the memory 10 when it is replaced by all 1's. The replacement character is regenerated via the decrementer 27 until the SOT tag is detected at the memory output when the replacement character is gated 32 to the system output. |
