DATA RECORDER WITH SINGLE OPERATOR ENTRY-VERIFY CONTROL

摘要

1305057 Verifiers MOHAWK DATA SCIENCES CORP 20 April 1970 [18 June 1969] 18776/70 Heading G4C A verifier system comprises a buffer for storing a block of characters generated by a keyboard. During subsequent operation of the keyboard the keyboard output is compared with the characters in the buffer. Bits representing the result of each comparison are stored to indicate which characters, if any, require correction. When correct the characters are read from the buffer to a magnetic disc or tape store. When a block of characters is fed from the keyboard to the buffer during an Entry mode an error control bit (EC) is generated in respect of each character. Each EC bit indicates whether the corresponding character of the present block is (EC=0) or is not (EC=1) the same as the character of the preceding block which it is replacing in the buffer. The EC bits are stored in a control store. If the operator presses a Skip key space characters are generated until a preset position in the block is reached. If a Duplicate key is pressed the corresponding characters in the buffer are unaltered and the EC bits = 0. Skip and Duplicate operations may be performed automatically. At the end of the block the system passes automatically to Verify mode. The operator rekeys the characters and each character now generated is compared with the corresponding character in the buffer. Where the comparison shows equality any stored EC bit that is 1 is reset to 0. If there is lack of equality the system switches to Error mode. The operator now rekeys the correct character. If the comparison now shows equality the Verify mode is re-entered. However, if there is still inequality this means that the character in the buffer is incorrect. By rekeying the correct character while pressing a special key the system is temporarily placed in the Entry mode, the incorrect character in the buffer is replaced by the correct one and the EC bit is set to 1. Verification then continues but at the end of the block transference of the block to the disc or tape store is prevented until any characters entered during the Correction mode have been reverified. This is done by automatically stepping the circuitry back to the first corrected character, indicated by EC=1, the operator then rekeying the correct character. When the block has been verified or reverified the block is automatically transferred to the disc or taps store. When the store indicates that the block has been received the system reverts to the Entry mode.