RCA 301, Programmer'S Reference Manual

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HI-DATA TAPE GROUP, MODEL 382
The Hi-Data Tape Group, Model 382, is composed of a cluster of six, four, or three tape stations having a
common set of control, power supply, and switching circuits. Each tape station can read or write binary coded
characters on '/> inch wide magnetic tape in response to programmed instructions. Two 8-inch tape reels are mounted
on each station; one a supply reel and the other a take-up reel. Each reel holds 1,200 feet of magnetic tape of which
a minimum of 1,150 feet are usable. The tape decks are designed to facilitate the manual changing of tape reels
within one minute.
Written tapes may be interchanged between individual tape stations or between units with complete compatibility.
Each tape station can be instructed to read in either the forward or reverse direction or to write in the forward
direction. Rewinding is at the rate of 120 inches per second and is completely independent of computing, once initiated.
Each tape station reads or writes at the rate of 30,000 characters per second in the 382 Mode. It accomplishes.
this by writing 500 characters to the inch while moving the tape at a speed of 60 inches per second. Inter-block gaps
are approximately .54 inch in length. An automatic write lockout feature is also provided to protect master reels.
Each of the 6 tape stations within a cluster is individually addressable. Up-to-speed time is 4.3 milliseconds and
rcad-after-write stop delay is 5.67 ± .5 milliseconds. There is no switching time. The tape stations are designed to
facilitate the manual changing of tape reels within one minute.
Two Hi-Data Tape Groups, Model 382, may be included in a system. When the Computer is equipped with the
Simultaneous Mode Control the two tape groups can be operated simultaneously.
An automatic accuracy control prevents the tape from running off the feed reel. A write lockout prevents writing
of information except on specifically designated reels of magnetic tape. Parity is checked on the tape station address
received from the computer. Parity is checked on the information written to tape by the incorporation of a read-
after-write parity check.
In order to provide compatibility with the Hi-Data Tape Group, Model 381, each tape station will be equipped
with two switches. The first switch (381) will permit a tape prepared on a Model 381 Tape Station to be read on a
Model 382 Tape Station. The second switch is used in conjunction with the first. When both are set, tapes will be
prepared on the Model 382 Tape Station that may be read on a Model 381 Tape Station. In the 381 Mode, each
tape station can read or write at the rate of 20,000 characters per second. It accomplishes this by writing 333
characters to the inch while moving the tape at 60 inches per second.
33 KC MAGNETIC TAPE STATION
The 33 KC Magnetic Tape Station is used for reading and writing binary coded characters on % inch magnetic
tape at a rate of 33,333 characters per second. Data is recorded at a density of 333 Vi characters per inch. The tape
speed is 100 inches per second, forward or reverse. Reading is possible in the forward or reverse direction; writing
is performed in the forward direction. All characters are dually recorded on tape, and parity is checked on all data
read or written. The tape station is designed to facilitate manual interchange of tape reels, which can be accomplished
in less than one minute.
The gap between blocks is nominally 0.45 inch. Tape-write-up-to-speed delay is 4.5 milliseconds.
33 KC Tape Stations may be operated in the system through Tape Adapters, Dual Tape Channels or a combina­
tion of both. The Tape Adapter connects a single Tape Station to the Computer. Two models of the Dual Tape
Channel (2x6 switch or 2x12 switch) are available which operate up to six, and up to 12 Tape Stations, respectively.
One 33 KC Dual Tape Channel and up to two 33 KC Tape Adapters may be connected to the Computer for operation
of up to 14 Tape Stations. When the Computer is equipped with the Simultaneous Mode Control two Tape Stations
can be operated concurrently.
66 KC MAGNETIC TAPE STATION
The 66 KC Magnetic Tape Station is used for reading and writing binary coded characters on % inch magnetic
tape at a rate up to 66,667 characters per second. Data is recorded at a density of 667 characters per inch nominally.
The tape speed for reading and writing is 100 inches per second. Tape rewind speed is 150 inches per second.
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