Multiple Tape Lister; Data Exchange Control; Random Access Computer Equipment; Data Record File - RCA 301 Programmer's Reference Manual

Reading is possible in the forward or reverse direction; writing (and erasing) are performed in the forward direction.
All characters are dually recorded on tape, and each character is read and checked for parity after it is written.
There is also a parity check on all characters read. 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 0.55 inch. Tape-write-up-to-speed delay is 3.5 milliseconds, and the read-
after-write stop delay is 2 milliseconds.
66 KC Tape Stations may be operated in the system through Tape Adapters, Dual Tape Channels, or a com­
bination of both. The Tape Adapter connects a single Tape Station to the Computer. Two models of the Dual Tape
Channel (2x6 switch or 2 x 12 switch) are available which operate up to six, and up to 12 Tape Stations, respectively.
One 66 KC Dual Tape Channel and up to two 66 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.

MULTIPLE TAPE LISTER

The Multiple Tape Lister, Models 340-6 and 340-12, is an electro-mechanical printer having 6 or 12 separate
paper feed units (two models). Printing is possible on any one tape or a maximum of two tapes with one instruction.
When two tapes are being printed with one instruction, the first
will always be printed and a designated one of the five
printing rate is up to 2,000 lines per minute.
Each of the six or twelve printing areas has the same format containing a maximum of 24 print positions. The
first 23 positions of each print area will be capable of printing the numerics (0-9) and five symbols ( . , # =
(minus) ). Position 24 will print a selected group of alphabetical characters (B, C, D, F, L, M, R, S, T, X, Y) and
four symbols (n, C , *, +).
R
Character spacing is 10 columns per horizontal inch and vertical spacing is six lines per inch.
The first character which is always sent to the Multiple Tape Lister is the Control Character. This character
supplies information to the Multiple Tape Lister concerning the tape(s) to be printed and paper advance. The next
24 or 48 characters sent to the Tape Lister are the information characters to be printed.

DATA EXCHANGE CONTROL

The Data Exchange Control, Models 377-1 and 377-2 enables any two 301 Processors, each equipped with this
control, to communicate with each other. A second Data Exchange Control may be included on a 301 Processor if
it is necessary for this processor to communicate with two other 301 Processors.
Data may be transmitted in either direction but in only one direction at one time. Either processor may initiate
a data transmission. Transfer of information from HSM to HSM is by diad.
The data transfer rate is dependent upon the mode in which the transfer is made and the availability of status
levels in both processors. For example, if the Normal Mode is used in both processors and nothing else is being
done, the maximum attainable transfer rate of 285.6KC (1 out of 1 status levels) can be achieved. The actual
transfer rate will be in a range between 285.6KC (1 out of 1 status levels) and 142.8KC (1 out of 2 status levels)
depending on the clock synchronization of the two processors. If the Simultaneous Mode is used in both processors
and nothing else is being done, the transfer rate will range between 142.8KC (1 out of 2 status levels) and 95.2KC
(1 out of 3 status levels) depending on the clock synchronization of the two processors. In a practical system, the
actual transfer rate will be dependent upon the available status levels in both processors when other operations are
being performed simultaneously with the data transmission.

RANDOM ACCESS COMPUTER EQUIPMENT

DATA RECORD FILE

Data Record Files are available to be used both as an extension of memory and as a medium for input-output.
Each Data Record File consists of 128 records which can be recorded on both surfaces. Each surface contains
two bands in which information is recorded in serial fashion in a spiral pattern around the record. Each band
or eleven other tapes will be printed. The maximum
i
(leftmost) tape of the Multiple Tape Lister
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