Punch Card Data Processing Examples


This set of examples takes you through a typical data processing sequence for a company. The card deck "master1.pcd" contains a set of customer "master" cards, each containing static information about a customer along with that customer's current balance. Credit balances are indicated by an "X" punch ('-' character) in column 40. These cards are kept in sorted order by customer ID, as a convenience. The file "detail1.pcd" contains customer transactions (e.g. purchases and payments). Payments are indicated by an "X" punch ('-' character) in column 40. These cards are not sorted, as they typically would come straight from data entry where they were punched from paper invoices - which were likely processed in chronological order, plus possibly punched by several different operators and then arbitrarely combined.

In order to process a month's transactions, first the detail cards need to be sorted by customer ID (using the sorter). Then, the detail cards and master cards need to be merged such that each customer card is followed by their transaction cards (using the collator). Finally, this combined deck of master-detail cards is passed through the accounting machine to produce a report and also to punch new customer master cards with updated balances (on the summary punch). These new customer master cards become the input for the next month's processing. The original master and details cards might be archived, but are otherwise not normally used again.

The Data

The customer master cards ("master1") contain data in the following format:

1-4Customer ID (numeric)
5-19First name (alphabetic)
20-34Last name (alphabetic)
35-39Zip code (numeric)
40"X" punch ('-') for credit
41-48Balance (numeric, 2 decimal positions)

The transaction (detail) cards ("detail1") contain the following data:

1-4Customer ID (numeric)
40"X" punch ('-') for payments (credits)
41-48Transaction Amount (numeric, 2 implied decimal positions)

Prerequisite - Data Entry

This step demonstrates the data entry phase. Since the output of this step is the card deck "detail1", which already exists, it is not strictly necessary.

The amounts must be entered as right-justified, zero-filled, 8-digit values with an assumed decimal point at 2 places. Since data entry input documents are typically prepared by humans, and even hand-written, an data entry operator must be able to glance at the value and know how many leading zeros (or blanks) to type. Experienced keypunch operators could very quickly predict how many zeros to punch.

Most good keypuch operators would never look at the card being punched (let alone the keyboard). Even with the best keypunchers, mistakes would happen. Data entry often consisted of two phases - data entry and data verification. For verification, a different operator would re-enter the data on a keypunch setup to verify - where it does not punch what is typed by only compares with what was previously punched and jams when there is a mis-match. The operator would then have to examine the document, card, and their own typing to determine where the mistake was. Verification is not covered in this example.

The input data document has data grouped by customer ID, although not in numerical order. Depending on how the original data was gathered, this may or may not have been the case for a given data entry job.

Start the DataCenter application, which provides central access to all punch-card data processing equipment.

  1. Start the Keypunch.
  2. Load the program card "detentry1" (DETail data ENTRY).
  3. Set the program bar to the left (on), turn on AUTO SKIP DUP and AUTO FEED (ensure that PROG 1 is selected).
  4. Ensure blank cards are in the input hopper.
  5. Press RELEASE (Enter) to feed the first card.
  6. Use the file "dataentry1.txt" to enter the data:
    1. If the customer ID is the same as the previous card, press DUP (Ctrl-D). Otherwise, type the 4-digit customer ID. The keypunch will skip to column 40.
    2. If the amount is a credit/payment, type '-' else type a space.
    3. Enter the amount, but it must be zero-filled and right justified. Do not enter the decimal point character. When the last digit is typed, the card will release and a new blank card will feed into the punch station.
    Once the data has been entered, save the output stacker cards into a file ("detail1").

NOTE: the program drum card may be viewed by pressing Ctrl-A. This also sends the current card to the output stacker, so keep that in mind. To return to data entry, press Ctrl-A again, which feeds another card.

Step 1 - Sort detail records

Start the DataCenter application, which provides central access to all punch-card data processing equipment.

NOTE: card decks may be viewed using the "Viewer" application, available in the "File" menu. Only saved files may be viewed, not the contents of hoppers or stackers.

Customer ID is in columns 1-4. Sorting must begin at column 4 and work towards column 1.

  1. Start the Sorter. Ensure setup is for numeric sorting.
  2. Load "detail1" into the hopper.
  3. Set column to 4.
  4. Press START. Once completed, ensure no cards were rejected.
  5. Click on the pockets, ensure pockets 0-9 are selected and that reverse picking (L-R) is NOT enabled. Set the RECYCLE option. Accept.
  6. Set column to 3.
  7. Repeat at step 4, reducing column by 1 each time, until completing column 1. Do not select RECYCLE for column 1 results, instead save into a new file. The following steps assume the saved file was "detail1s".

Step 2 - Merge master/detail records

  1. Start the Collator.
  2. Load program panel "merge1".
  3. Load "detail1s" into the SECONDARY hopper.
  4. Load "master1" into the PRIMARY hopper.
  5. Press START. Once the collator stops, press RUNOUT. All cards should be in pocket/stacker 2.
  6. Click on the pocket (stacker 2) and save to a new file. For this example, the new file is assumed to be "records1".

Step 3 - Compute new balances

  1. Start the Accounting Machine.
  2. Load program panel "report1". This will cause the Reproducing Punch (Summary Punch) to appear.
  3. On the Reproducing Punch:
    1. Load program panel "report1".
    2. Make certain the REPRO switch is off.
    3. Load at least 50 blank cards into the punch hopper.
  4. Load "records1" in the Accounting Machine hopper.
  5. Press START on the Accounting Machine. When the machine stops, press FINAL TOTAL.
  6. Use the "Paper" menu to save the report in a text file.
  7. On the Reproducing Punch:
    1. Use Shift-Right-Click on the punch hopper to remove all cards.
    2. Press START to runout the last cards.
    3. Click on the punch stacker and save the cards ("master2").

NOTE: At this point, the new balance cards in "master2" contain only the customer ID and new balance. Additional customer info must be transferred from the previous master cards ("master1").

Step 4 - Extract master cards from combined deck

NOTE: since we have the original "master1" file in-tact, this step is not necessary in a virtual world. But, in the old days, the master cards needed to be isolated from the detail cards in order to copy (only) their data to the new master cards. One method is to use the Collator to extract master cards into a separate pocket. An example of this method follows.

  1. Start the Collator (if not already).
  2. Load the program panel "separate1".
  3. Load the "records1" deck into the primary hopper.
  4. Press START. Cards should be sent to both stacker 2 and stacker 1. Stacker 1 will contain the master cards. don't forget to press RUNOUT.
  5. Save stacker 1 to a file, and use that file in place of "master1" in the next step.

Step 5 - Copy customer information to new balance cards

  1. Start the Reproducing Punch (if not already).
  2. Load program panel "master1".
  3. Set the REPRO switch on.
  4. Load "master1" in the read hopper (or the deck created in step 4).
  5. Load "master2" (from step 3) in the punch hopper.
  6. Press START. If any cards are out of order (customer ID mismatch) then a comparing error will result.
  7. Click on the punch stacker and save the complete new balance cards.

This saved deck is now ready for input to the following month's processing.