Data synchronization apparatus

Details Data synchronization apparatus Data synchronization apparatus

1981-09-21

1984-08-28

Smith, Jerry

Boots, shoes, and leggings

375110, 375116, 360 44, 360 51, 370100, 371 47, G06F 300, H04L 300, G11B 506, G08C 2500

Patent

active

044687524

ABSTRACT:
Data synchronization apparatus for a 1500 baud computer-audio frequency magnetic tape recorder interface is disclosed. The synchronization apparatus automatically detects bit cell boundaries and synchronizes at both the bit level and the byte level even if the audio waveform as read from the tape is inverted, as is the case with some tape recorders. Synchronization is performed by converting the audio waveform into a square wave and examining the square wave for predetermined pulse patterns. If one pattern is found, the positive-going edge of the waveform is selected as the bit cell boundary. If, on the other hand, another pattern is found, negative-going edges are selected as bit cell boundaries. Synchronization is achieved on a byte level by shifting incoming data into a first-in/first-out buffer and examining the stored data for a predetermined bit pattern.

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