RCA 301, Programmer'S Reference Manual

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The Card Reader-Punch consists of a card reader and card punch in the same enclosure. The Reader Unit, under
program control, will either: (1) automatically convert 80-column Hollerith card code to 301 code for transfer
to HSM, or (2) read a card image into HSM for processing or translation by program. Reading occurs a row at a
time at rates up to approximately 800 cards per minute, with 10 milliseconds of free compute time per card cycle.
When the read-release program option is exercised, an additional 21 milliseconds of compute time per card cycle is
available. Two read stations permit a hole count accuracy check to be performed.
The Punch Unit punches 80-column cards in either Hollerith or binary code, as specified by the stored program.
Punching is performed at rates up to approximately 250 cards per minute with 22.5 milliseconds of compute t;me
per card cycle. An additional 37 milliseconds of compute time is available when the punch-release program option
is utilized. Verification of the punched data by a read station is performed on the succeeding card punch cycle.
The input hopper of the Reader Unit holds 3,000 cards, and the input hopper of the Punch Unit holds 1,200
cards. There are five output stackers. (Two stackers for the reader, two stackers for the punch; the center stacker
may be selected by either the reader or punch.) Concurrent card reading and punching operations may be performed
when the system includes the Simultaneous Mode Control.
PAPER TAPE EQUIPMENT
The paper tape equipment includes the Paper Tape Reader/Punch, the Paper Tape Reader, the Paper Tape
Punch and the High Speed Paper Tape Punch.
The Paper Tape Reader/Punch is mounted on the same base. The Reader and the Punch both operate at a rate
of 100 characters per second. The unit writes to or reads from 5-channel or 7-channel paper tape. Gapless tape
can be read. The seven channels across the width of the tape correspond to the seven bit positions (six information
and a parity bit) of an RCA 301 character. When a character position on paper tape contains a punch in all seven
channels, it is interpreted as "delete character," it is not an RCA 301 character and no attempt is made to read
it into the Computer. When 5-channel tape is being read, the 2" position is interpreted as a zero bit and correct
parity is placed in the 2° position to result in a 7-bit character being placed in HSM. When punching 5-channel
tape, the 2° and the 2' bits of each character are stripped off after the character is called from HSM resulting in
a 5-bit character being punched on tape. Both reading and punching can progress simultaneously if the System has
a Simultaneous Control Unit. Parity is checked on all information read and on all information received at the Punch.
Packing density is 10 characters per inch. Tape speed is approximately 10 inches per second. The Reader stops on a
character and in a position ready to read the next character. The Stop-Start Distance of the punch is 0.3 inch, or
3 sprocket holes, from the last character punched.
The Paper Tape Reader reads 5, 6, or 7-level paper tape at speeds of approximately 500 or 1,000 characters
per second. When 5 or 6-level tapes are read, additional bits are added in the most significant bit locations to
produce 7-level characters of correct parity to be stored in HSM. At the 500 characters per second rate, the Reader
stops on a character and in a position to read the next character. At the 1,000 characters per second rate, the
Reader stops in a position to read a character at a maximum of 0.3 inch (three sprocket holes) from the last
character read. Packing density on tape is 10 characters per inch, and tape moves at 50 or 100 inches per second. An
adjustable guide is provided to handle tape in widths from
n
/
16
inch to one inch. Unwind and take-up reels may
be used for reading tape lengths up to 1,000 feet. All small Characters are checked for correct parity.
The Paper Tape Punch punches 5, or 7-level paper tape at speeds of approximately 100 characters per second.
When 5-level tape is punched, the two most significant bits of each 7-bit character received from HSM are ignored
resulting in a 5-bit character to be punched. The Punch stops in a position to punch a character a maximum of 0.3
inch (three sprocket holes) from the last character punched. Packing density on tape is 10 characters per inch,
and tape moves at approximately 10 inches per second. All information received at the Punch is checked for parity.
The High Speed Paper Tape Punch, Model 332, punches 7-level paper tape at a speed of approximately 300
characters per second. There is a combined pushbutton control and indicator on the punch unit. When this is set,
a three-character gap will be generated between blocks of information. When the indicator is reset, the punch will
stop on a character location in position to punch in the next character location.
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