| 摘要 |
943,582. Magnetic ledger cards. ING. C. OLIVETTI & C. S.p.A. April 10, 1962 [April 11, 1961], No. 13810/62. Heading G4M. A ledger card 1 has a magnetic track 2 on which is recorded the old balances. A parallel track of the same length as track 2 comprises magnetic marks the sensing of each of which switches on a Schmitt trigger 107 for a time determined by condenser 105 which is less than the time taken for successive marks to pass transducer 44. The output of the trigger maintains transducer 42 operative for reading or writing on the track 2. The track 4 may be identical to track 2 but have recorded thereon a series of one bits. Specification 916,305 is referred to. |
