1. First Read Brushes. These are exit hubs (Figure 191) for impulses originating as the card is read at the first reading station. These hubs are used to pick up selectors for alphabetic control, loading, etc.
2. RD
+
Read Plus Sign. This switch must be con-nected when input cards are punched with 12's over positive numerical fields.3. Offset. These hubs are impulsed early in the cycle in which a card is stacked. They are normally wired from cycle delay out, pilot seleetor coupling exit, normally used to pick up selectors, impulse OFFSET
or AUTO STOP. control-panel wiring. When load has been impulsed, the contents of the eighty columns in the card are transferred automatically to storage words 1-8.
7. Auto Stop. These hubs accept impulses to suspend reader operation at the end of that read cycle.
8. Cycle Delay. An impulse wired to the in hub of the cycle delay unit causes an impulse to emit from the corresponding out hub one cycle later. impulsed at the pickup hub, an impulse wired to the c hub is available at the N (normal) hub.
11. Couple Exit. These hubs emit an impulse whenever the corresponding pilot selector is transferred. This impulse is normally used to control other pilot directly or through properly controlled selectors.
14. Field Selectors. There are ten II-position field selectors provided. Field selectors 1-5 have three levels each: (Normal, levelland level 2). Field selectors 6-10 have four levels each: (Normal, levell, level 2, and level 3). When a field selector is impulsed to transfer at a given level, a connection exists between common and that level. If the field selector has not been impulsed, the connection is between common and normal.
15. Storage Entry. These are the 96 entry hubs to the input-synchronizer. They are normally wired from the third reading brushes to enter data in any de-sired format. Each wired storage entry position must receive a valid character from the reading brushes.
In an alphabetic word only, a blank is a valid char-acter. The ring check light comes on if less charac-ters are read than the number indicated by the wiring to ENTRY END. The transfer of an invalid character activates the validity check and re-cycle circuits.
16. Altr SW. There are four alteration switch selectors on the control panel that correspond to the four alteration toggle switches on the machine. When the alteration toggle switches are turned on, the corresponding selectors transfer. The selectors can be used independently or in conjunction with controlled to transfer automatically between 0 and X time as the card is read. This allows the 12 and X punches to be separated from 0-9 punches for storage entry, pilot, field, and co-selector control, etc.
20. Column Split Couple. An impulse is emitted from these common hubs between X and 0 read time.
This impulse is used to pick up co-selectors to ex-pand the column-split feature.
21, 22. Digit Selector. The DIG IMP (Digit Impulse)
a reading brush is wired to the C hub, whatever digit is read is available at the corresponding num-bered hub of the digit selector.'
23. Half-Time Emitter. These are off-time emitter hubs that emit an impulse at half after the number they represent. They are normally wired to pick up selectors that are then used as column splits.
24. Digit Emitter. These hubs emit read-digit impulses on every read-feed cycle. They are used to enter data that is not available in the input cards into storage.
25, 26. Fld Sel PU. Field Selector Pickup. These hubs are impulsed to cause the corresponding level of the field selectors to transfer on the following cycle.
The field selector couple exit hubs emit impUlses whenever the corresponding level of the field selec-tor is active. They are normally wired to co-selecselec-tor pickups to expand the field selectors for specific levels.
27, 28. Load Zero Exit. Load Zero Entry. These hubs are associated with the eight input words that are active on load cards. If any word in a load card contains invalid information, the load zero entry hubs associated with that word must be wired from the load zero exit hubs. That word will be filled with zeros in the input synchronizer.
29. Alphabetical In. When these hubs are wired from the CAl hubs, alphabetic translating circuitry is activated to convert the IBM card code to 2-digit numerical coding for the 7070. An alpha sign is entered into the sign position of the designated word.
30. CAl-Constant Alphabetical Impulse
a. D-Detail. This hub emits an impulse on all read cycles except load cycles.
b. L-Load. This hub emits an impulse on load cycles only.
CAI-L and CAI-D can be selected and are nor-mally wired to ALPHABETICAL IN.
31. 12-Impulse. These hubs emit 12 impulses on all read cycles.
32. O-Impulse. A 0 impUlse is emitted from these hubs on all read cycles.
33. Second Read Brushes. Impulses are emitted from these hubs as the input card passes the second read-ing station. These impulses are normally used for picking up selectors and for pre-reading alphabetic data.
34. Co-Selectors. Sixteen co-selectors are standard.
Each selector has five positions. When the pickup hubs are impulsed, the selector transfers imme-diately and holds to the end of the same cycle.
35. Alph Pre-Read. These are entry hubs for impulses emitted from the second read brushes when alpha-betic data is to be entered into storage. The same card columns that are wired to ALPH PRE-READ from second reading must be wired to STORAGE ENTRY
from third reading.
36. Entry End. Units, Tens, Exit. These hubs are wired to set up for a ring check the total number of character positions that have been wired to storage entry for a given card format. If the count of char-acters in storage entry does not equal the number wired to ENTRY END, the ring check signal comes on.
37. Word Exit. These 16 hubs emit sequentially as words 1-16 are transmitted to the input synchron-izer for entry to storage. These impulses are always wired to the word-size entry hubs to cause the proper number of characters to be entered.
38. Word-Size Entry. These hubs are wired from the word exit hubs to cause specific numbers of charac-ters to be entered into the input synchronizer for each input word.
One to three IBM 7550 Card Punch units (Figure 192) can be attached as output devices for the IBM 7070 Data Processing System. Information from the output syn-chronizer is directed by the control panel to punch cards in any desired format.
During continuous operation, a maximum of 250 cards a minute can be punched.
FIGURE 192. 7550 PUNCH