RCA 301, Programmer'S Reference Manual

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% Record File Mode Write (RMW)
General Description
This instruction writes from a selected HSM location to designated cells in one of the four Data Record Files
connected to the Data Record File Mode Control Unit. From one to ten blocks of information may be transferred
to the Record File with one instruction. A cell can contain a block of information of from one to 900 characters.
In writing, a block is terminated by an End of Block (EB) Symbol, or a cell count of 900 characters.
Format
Operation —%
N Selects the Data Record File Unit and the number of blocks to be written as indicated below:
Number of Blocks
to be Written
1 2
3 4 5
6
7 8
9 10
First File
1
2
3
4 5
6 7
8
9
0
Second File
A
B C
D E F
G H
I &
Third File
J K L M
N O
P Q
R
minus
Fourth File
/
S T
U V
W X Y
Z
> >
A Address — HSM address of first character to be written to the Record File.
B Address — B
0
must be zero (0).
Bj determines if record stays on turntable after operation.
Bj = odd — record returned to cage.
B, = even — record stays on turntable and arm is placed at beginning of previously selected
band.
B
2
specifies whether EB sensed or not.
B
2
= 1 — block is terminated on counting of 900 characters.
B
2
= 0 — count or EB recognition.
If EB sensed before 900 characters have been written, stop transfer to this cell. If
900 count reached before an EB sensed, stop transfer into this cell.
B
3
addresses cells 1 through 10, with cell 1 specified by zero and cell 10 specified by 9.
Direction of Operation
Left to right in HSM.
Outline of Operation
Initially this instruction is staticized in the Normal Mode. If the Record File Mode is free, the contents of
the NOR, N, A, and B Registers are transferred to the FOR, L, U, and V Registers respectively, and this instruction
is executed in the Record File Mode. A start signal is sent to the selected Data Record File and the arm is placed
on the previously selected disc on the turntable. As soon as the Normal Mode is interruptable, the contents of the
HSM location specified by the U Register are transferred to the Record File Mode Buffer and from the buffer to
the specified cell. The contents of the U Register are increased by one and the contents of the HSM location now
addressed by the U Register are transferred in a like manner. When the end of a block is reached, determined by
V
2
, L is decreased by one. When L is decreased to zero, the operation terminates. The record does not have to be
returned to the cage to perform other read or writes to the same surface.
Final Register Contents
(U)
t
= Address of location one to the right of the last character written on the record.
(V)
E
= (B)
s
XI-17