Punched Cards - IBM 709 General Information Manual

moved. This makes the drum valuable for overnight
storage of intermediate results during the processing
of involved problems.
The
IBM
733 Magnetic Drum (Figure 85) is one of
two input-output units in the 709 system that function
without being dependent upon the data synchronizer.
The other unit is the
IBM
740
CRT
Output Recorder
and Display Unit. The 7090 system does not use the
magnetic drum, or any of the
CRT
equipment.
Punched Cards
In most applications, magnetic tape is used as the
principal input medium. It may also be desirable to
use
IBM
cards as an input medium in some situations
where the volume of input is sufficiently small to per-
mit an economical operation. In either case,
IBM
cards
are used for initially recording data because of their
great flexibility. Errors are easily detected and cor-
rected, input data may be readily prepared on several
card punch locations simultaneously and the cards
may be collected at a central location before entry
into the computer.
Entering a program on cards may be done in such
a way that instructions are punched, one to a card,
in the most desirable form to the programmer. The
computer can then be supplied with a standard pro-
gram to assemble the instructions in the desired order.
Then, if errors are detected or if changes must be
made, the error cards are removed, the correct ones
are added, and the computer prepares the new pro-
gram. Note that there is no need to repunch all cards
but only the cards in error.
0 2345 67139A'BCD F
IJjL I:IOPQRS
'U
ni l
I
y:+-
I
...
I
II
I
I 10 0
j
" "
'
..
1 1
1
22
2
333 33
33
4444 444 444
44
55555
5555 5555
555
666666 66666
66666
6666
7777777 777777
777777 77777
88888888 8888888
88888881 888888
999999999 99999999 99999999 9999999 999999999999
12345611'WII1213"'516'7aI9m~u~N~ana~~3In~~»~v~~*~~U"u*~*
Figure 86. Standard
IBM
Card Code
Punched card input and output may represent any
alphabetic character, special symbol, or binary punch-
ing if the assembly program handling it is able to rec-
ognize the code used. The standard
IBM
card code is
shown in Figure 86.
Only 72 card columns of the
IBM
card can be read
into or punched from core storage during any given
storage reference cycle. Any 72 of the possible 80 card
columns of the card can be selected through use of a
control panel on the card reader and the proper wir-
ing on that panel. Figure 87 shows how the card may
be punched to record data in binary form. In this
particular example, the first 72 columns of the card
are used. Each row is split into half-rows of 36 card
columns, each corresponding to the 36-bit binary
word. Thus, the half-row identified by the circled 9
is named the 5-row left. Similarly, the row identified
by the circled 10 is named the 5-row right.
I
~ ,---------left
H a l l - - - - - - -.....
+! .... - - - - - - - Right
Hall _ _ _ _ _ _
- ! •
..J!-4._~ni"ed
-i
o um"s
®
@
12-Raw
® @
ll-Row
0000000000000000 O@OO 0 0 0 0 0 0 0 0 0000000 00000000000000000 ®O 0 0 00000000000000 00000000
7374757&77781980
11111111111111111@11111111111111111 11111111111111111@11111111111111111 111 II 1 II
222222222
n
2 2 2 2 2 2@>2 2 2 2 2 2 2 2 2 2 2 2 2 2 222 2222222222222222 2@2 2 2 2 2 2 2 2222222222 22222222
33333333333333333@33333333333333333 3333333333333333 3@3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 33333333
4444444444444444 4@4 4 4 4 4 4 4 4 4 4 4 4 4 4444 4444444444444444 4@4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 44444444
55555555555555555055555555555555555 5555555555555555 5@5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 55555555
66666666666666666066666666666666666 66666666666666666@66 6 6 6 6 6 6666666666 66666666
7777777777777777 7@7 7 7 7 7 7 7 7 7 77777777 777777777 7 7 7 7 7 7 7 70777777 7 7 7 7 7 7 77 7 7 7 77777777
8888888888888888 8@888 8 8 8 8 8 8 8 8888888 88888888888888888088888888888888888 88888888
9 9 9.9 9 9 9 9 9 9 9 9 9 9 9 9 9
0
9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 999999999999999 9
9~9
9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 99999999
123456789mnUDM~mnmw~n22nN~Hvna~M»nM~H 31383940414743444541474849505152535 5565758 59 60 6162 6364 65 6667 6169 70 7112 1374157617 78 7980
Figure 87. Sequence of Card Reading
Input-Output Components 39