That article shows the machines, but gives no sense of how they are used together.

Here's a simple billing cycle. Inputs are:

- Purchases, with a description, customer number and amount. These were created manually, by a keypunch operator. Cards would also have date and card type, copied from card to card while punching.

- Payments, with a customer number and amount. Again, with date and card type, copied from card to card.

- Customer addresses, usually a 3-card set, with name and address, customer number, and card type. These are semi-permanent, used month after month, updated by hand.

- A previous balance card for each customer, with customer number, amount, date, and card type.

So, at the end of a billing period, the first step is to sort all the purchase cards by ascending customer number. That's what the 082 sorter is for. They should have been accumulated in date order, although if you have to sort by date, you can. Sorting is labor-intensive, because all the sorter does is a 1-digit radix sort. So if you have a 5-digit customer number, you have to put all the cards through five times. You don't want to have an unnecessarily long customer number. There's a lot of manual card handling here, but it's mindless.

Payment cards get the same sorting treatment, by customer number.

Previous balance cards and address cards should already be in order by customer number, and that will be checked.

Now the 085 collator is used. First, the address cards and previous balance cards go into the two hoppers. The collator can read selectively from either hopper. The only operation the collator can do is compare numbers, less, equal, or greater. But that's enough. The collator combines the address deck and the previous balance deck, so that the deck, for each account number is now

Address 1, address 2, address 3, previous balance.

Any previous balance card without an address or an address without a previous balance card is caught at this time. Those cards may go into a different output stacker, or the collator may be stopped for a manual check, depending on how the plugboard was wired.

Next the another collator pass - the deck from the previous step vs. the payment cards. Now the deck is

Address 1, address 2, address 3, previous balance, payments.

Now the big collator pass, where the purchase cards are merged in.

Address 1, address 2, address 3, previous balance, payments, purchases.

The collator has checked that everything is in the right sequence, with all cards in a block having the same customer number and successive blocks having ascending customer numbers. That's the final deck, and it now goes to the 403 tabulator.

The tabulator has one hopper and one stacker, a printer, and a big removable plugboard that's the program. The data processing shop will have a rack of such plugboards for different jobs.
There will be custom-printed multi-part carbon forms, and a "carriage tape" loop, which tells the printer how much to advance the paper to get to the next section of the form. The 403 has very little memory, about 40 decimal digits, although you can buy a few extra counters from IBM if you have to.

So now it's time to print the bills. The final deck is loaded, 500 cards at a time or so. The 403 grinds into action. The address cards are read, and they print in the address block on the form, which will be visible in a window envelope when mailed. Totals are cleared. When the tabulator detects the change from an address card type to a previous balance card, the carriage is told to advance to the line indicated by a hole in the carriage tape. This moves the paper to the beginning of the transactions area. The balance forward is printed on the balance forward line, and added to the total. The purchases follow, again being added. The payments follow, and those are subtracted. When the reader sees a new address card, that indicates the end of this customer.

So the tabulator advances to the total line on the form, and prints the total amount due. An invoice has been generated, and will later go into an envelope to be sent to the customer.

Remember that 514 Reproducing Punch? That's been cabled to the 403 tabulator via a huge cable and connector, for Summary Punch mode. When the tabulator prints the total amount due, it sends the total and customer number to the 514, which punches a previous balance card with the new balance, to be used next month.

You get the idea. One cute feature is that you can program the 403 to detect a hole punched in the carriage tape which indicates the form is full. Then it can print a per-page total, increment the page number, start a new form, repeat the customer number, and continue printing transactions. Yes, they thought of that problem.