Table 4. Automatic Mode Stacking Action
Order
Stacking Action t
X
1
06
1
X
I
16
1
X
I
36
1
X10E 1
X
I
3E
1
Model 7120
Stack card in normal stacker.
Stack card in alternate stacker 1.
Stack card in alternate stacker 2.
If no validity error or data overrun occurs,
stack card in normal stacker; if validity
error or data overrun occurs, stack card in
alternate stacker 2.
If no val idity error or data overrun occurs,
stack card in alternate stacker 1; if validity
error or data overrun occurs, stack card in
alternate stacker 2.
Stack card in al ternate stacker 2.
Model 7140
Stack card in normal stacker.
Stack card in al ternate stacker.
Stack card in normal stacker.
If neither validity, data overrun, nor read
verify error occurs, stack card in normal
stacker; if error occurs, stack card in alter-
nate stacker.
Stack card ina
I
ternate stacker.
Same as 10E
I .
tModels 7121/7122 accept all the above order codes but offer no alternative stacking since they have only one stacker.
READ CARD AUTOMATIC
The orders (hexadecimal code) listed in Table 4 cause the
card reader to feed and read a card in the automatic mode,
with the card being directed to one of the multiple stackers.
To facil itate reading of intermixed EBCDIC and binary card
decks, card col umn 1 is sensed for the presence of punches
in rows 1 and 2; if both are present, the read operation is
automatically forced to the binary read mode and all data,
including column 1, is transmitted as described previously
under IIBinary Card Format
ll
•
In the EBCDIC card format, 80 bytes are present on a card.
Incorrect length will be signaled if either fewer or more
than 80 bytes are requested for an EBCDIC card. However,
if the binary read mode is invoked automatically, incorrect
length will be signaled if either fewer or more than 120
bytes are requested.
KEY EVENTS
The key events that occur during a card read operation are
described in the following paragraphs.
No chronological
order should be assumed from the order of presentation.
Timing information is discussed under IIProgramming
Considerations II •
ST ART INPUT IOUTPUT
A card read operation is initiated with the execution of a
START INPUT/OUTPUT instruction by the controlling sys-
tem
Q
If I/O address recognition exists and the reader is in
the IIreadyll condition with no interrupt pending, the con-
trolling system sets its
111/0
address recognition
IJ
and lISIO
6
Key Events
accepted
ll
indicators.
The card reader advances from the
II ready II to the IIbusyll condition and, if the reader is in the
lIautomati c
ll
mode, it requests an order byte from the con-
troll ing system. Note that IISIO accepted
ll
does not mean
that the card reader has started to feed and read a card.
I1SIO accepted
11
signifies only that a device has accepted
the SIO instruction and the device was in the II rea d y
ll
con-
dition with no interrupt pending.
UNUSUAL END CONDITIONS
The detection of any of the following during the IIbusyll con-
dition causes the card reader to return an II unusual end II indi-
cation to the control
I
ing system at the time the condition
occurs:
1.
Invalid order code
2.
Read station malfunction
3.
Transport mechanism malfunction
4.
Absence (or failure) of ac and/or dc power in reader
5.
Operator pressing the RESET switch
6.
The occurrence of a data overrun
7.
lOP Halt (not applicable to Sigma 2)
CHANNEL END CONDITIONS
After receiving an order from the control
I
ing system, the
card reader signals
II
channel end ll to the control
I
ing system
when the end of the card is encountered or an lIunusual end II
condition occurs, whichever occurs first.
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