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THE TAPE UNITS
Cartridge tape operations is divided between the cartridge
tape hardware and firmware. The hardware maintains
constant speed and provides for selection of fast or slow
speed and the direction of tape motion.
A line of data on the screen is recorded on the tape as a
record. The information is stored serially on the tape at a
recording density of 800 bits per inch and a read/write
speed of 10 inches per second. Data is organized into files,
records, bytes, and bits. Separating the files are file
marks, special-length gaps (areas of unidirectional mag-
netization) with a file identification record between them.
General Description
Holes are punched at each end of the tape to provide
reference for beginning of tape and end of tape. If a hole is
detected in the tape, indicating tape location, tape motion
is stopped until the firmware commands it to start again.
The hardware encodes and decodes data bytes into bit
patterns on the tape and records interrecord gaps. The
hardware reacts to commands given by the firmware and
presents status information to the firmware.
The firmware controls all tape motion and maintains
tape-position information. The firmware dictates whether
the hardware is reading, recording, or writing gaps. It
formats data into records and generates special tape
marks that have significance in organizing the tape into
records and files.
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