RCA 301, Programmer'S Reference Manual

Page: 114 / 235

5 Tape Read Forward Simultaneous (RFS)
General Description
This instruction brings a series of consecutive characters from magnetic tape or punched paper tape into the
HSM. Transfer from tape begins with the first character following a gap and ends when the next gap is sensed or
the specific HSM area is filled. When rdhding gapless paper tape, transfer begins with the first character and ends
when the specified HSM area is filled or a gap is sensed. This instruction is performed in the Simultaneous Mode.
Format
Operation — 5
N — Identification character of Tape Station, Paper Tape Reader, or Interrogating Typewriter. (See
Appendix G.)
A Address — Address of location in HSM which is to receive the first character read.
B Address — Address of location in HSM which is to receive the last character read.
Direction of Operation
Left to tight.
Direction of Tape Motion
Forward
Outline of Operation
Initially this instruction is staticized in the Normal Mode. If the Simultaneous Mode is free and the SMDI
button is not on, the contents of the NOR, N, A, and B Registers are transferred to the SOR, M, S, and T Registers
respectively, and this instruction is executed in the Simultaneous Mode. This instruction sends a start signal to the
input unit specified by the contents of the M Register. The first character following a gap on tape or the next
character on gapless paper tape is placed in the tape buffer, and this instruction operates in the following cycle:
When reading other than 66 KC tape, the character in the input buffer is transferred to the HSM location specified
by the S Register. The contents of the S Register are compared with the contents of the T Register. The contents
of the S Register are incremented by one. If a gap is passed in sequence, the instruction terminates. If the comparison
proved equal and a gap is not passed, the instruction terminates, and tape movement continues to gap. If the
comparison proved not equal and a gap is not passed, the cycle is repeated.
When reading 66 KC magnetic tape two characters are transferred from tape to the input buffer and then to
HSM, and the S Register is incremented by two. Otherwise, the instruction operates as stated above.
If an EF or ED alone is read from magnetic tape, the EF/ED Simultaneous Indicator is set. The EF/ED
Simultaneous Indicator is not set when reading from paper tape. If SMDI is set, the EF/ED Normal Indicator will
be set.
Final Register Contents
(S)
f
= One location to the right of the last character read into HSM.
(T)
t
= (B),
Timing
Hi-Data tapes, Model 381, are read at the rate of 10 KC.
Hi-Data tapes, Model 382, are read at the rate of 30 KC.
Paper tape is read at the rate of up to 1000 characters per second.
The tape station attached to the Tape Adapter or Dual Tape Channel is read at the rate of 33.3 KC if it is a
Model 581 Tape Station or 66.7 KC if it is a Model 582 Tape Station.
The Interrogating Typewriter prints at a rate up to 10 characters per second.
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