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Hardware Load and the Paper Tape Reader
Once initiated, the loading of data from the paper tape reader is accomplished entirely under
hardware control.
A special format (operation code), in channels 7 and 8 {the control channels)
controls the shift of data in channels 1 - 6 from the reader to the B-register and then into memory.
The characters in channels 1- 6 are transferred into the B-register and assembled to form a
word. Since the DATANET-30 word is
18
bits, two shifts of 6 bits each are required.
18
~
SL6
13
12
~
SL6
7
6
1
t
6 bits from reader
When the B-register is filled with the third transfer of data into B, the word is transferred
to memory. {Operation code 01.XXXXXX.)
Operation code in
channels
8
&
7
8 7
654321
1 0 111111
0 0
xxxxxx
0 1
xxxxxx
1 1
xxxxxx
Operation
Begin hardware load. The reader searches for this code before the transfer
of data can start.
SL6 BR, B
Bits 1 - 6 from the paper tape reader are OR-ed into 1 - 6 of Y with the
contents of the B- register.
Y is shifted left 6 to
z.
Z is transferred to
the B-register.
TRA BR, B
Store B in memory location specified by P.
Count P up 1. Clear B.
Bits 1-6 from the paper tape reader are OR-ed into 1-6 of Y with the
contents of the B-register.
Y is transferred to Z without change. Z is
transferred to the B-register.
The contents of the B-register are stored
in memory as specified by P.
P is counted up by 1, and the B-register
is cleared.
TRA BR, B
TRA B, P. Clear B
Bits 1- 6 from the paper tape reader are OR-ed into 1-6 of Y with the
contents of the B-register. Y is transferred to Z without change.
Z is
transferred to B.
Then the contents of the B-register are transferred
to P, and the B-register is cleared.
[IDruu&~~uCJ ~@------------
V-55
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