V*
6 Tape Read Reverse Normal (RRN)
Repeatable
General Description
This instruction transfers 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 specified HSM area is filled. Though the tape moves in reverse, the characters will be placed in their proper
relative position within HSM.
Format
Operation — 6
N
—Identification character of Tape Station or Paper Tape Reader. (See Appendix G.)
A Address — Address of HSM location to receive the first character read from tape.
B Address — Address of HSM location to receive the last character read from tape.
Direction of Operation
Standard Location
Right to left.
STA (0212 - 0215)
Direction of Tape Motion
Magnetic tape moves in a reverse direction. Paper Tape will be moved in a forward direction, but the characters
read from paper tape will be placed in memory from right to left.
Outline of Operation
Initially this instruction sends a start signal to the input unit specified by the contents of the N Register.
After a gap is passed on magnetic tape, the first character 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 tape buffer is transferred to the HSM location specified
by the A Register. The contents of the A Register are compared with the contents of the B Register. The contents
of the A Register are decremented by one. If the comparison proved equal and a gap is passed in sequence, PRZ
is set, the instruction terminates. If the comparison proved equal and a gap is not passed, PRP is set, the instruction
terminates, and tape movement continues to gap. If the comparison proved not equal and a gap is passed in sequence,
PRN is set, the instruction terminates. 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 A Register is decremented by two. Otherwise, the instruction operates as stated above.
If an EF or ED alone is read from magnetic tape, the EF/ED Normal Indicator is set. The EF/ED Normal
Indicator is not set when reading from paper tape.
If ETW is passed the ETW flip-flop is reset.
Final Register Contents
(A)
r
= Address of location one to the left of the last characters read.
(®)t — ( B),
PRI
PRP: The A and B Registers are equal before a gap has been found on tape.
PRN: A gap has been found on tape and the A and B Registers are unequal.
PRZ: The A and B Registers are equal at the time a gap has been found on tape.
IX-7
Содержание 301
Страница 6: ...HRSfOTPflf I I I I ...
Страница 16: ......
Страница 34: ......
Страница 43: ......
Страница 44: ......
Страница 47: ......
Страница 48: ......
Страница 61: ......
Страница 62: ......
Страница 74: ......
Страница 75: ......
Страница 76: ...j I j I I ...
Страница 86: ......
Страница 87: ......
Страница 88: ......
Страница 108: ......
Страница 109: ......
Страница 110: ......
Страница 126: ......
Страница 127: ......
Страница 128: ...X ry V ...
Страница 134: ......
Страница 135: ...INPUT OUTPUT INSTRUCTIONS DATA RECORD FILE INPUT OUTPUT INSTRUCTIONS DATA RECORD FILE XI l ...
Страница 136: ......
Страница 154: ......
Страница 156: ......
Страница 175: ......
Страница 176: ......
Страница 180: ...WWH H i i w m H H J V fi t y v if i Hk I ...
Страница 182: ......
Страница 195: ......
Страница 234: ......
Страница 235: ...d STZ i T J t A p r TTqpe Deivc i L J I 1 G_ F O N _ _ O u I p y f 7 e i o o n p i uj e To o u r p e j C eu ...