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Glenn’s Computer Museum

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IBM Punched Cards
Figure 1
IBM 402 Control Board
Figure 3
IBM 557 Control Board
Figure 5
IBM 533 Control Board
Figure 7
IBM 602 Control Board
Figure 9
IBM 6400 Control Board
Figure 11
IBM 402-403 Control Board
Figure 13
IBM 407 Control Board
Figure 15
IBM 407 Control Board
Figure 17
IBM 407 Program Example
Figure 2
IBM 402 Control Board
Figure 4
IBM 88 Control Board
Figure 6
IBM 602 Control Board
Figure 8
IBM 514 Control Board
Figure 10
IBM 063 Control Board
Figure 12
IBM 85 Control Board
Figure 14
IBM 407 Control Board
Figure 16

IBM Card Equipment Programming Plugboards

I love IBM card equipment!

Until the early '60s, most business applications were done on standalone card processing units (called by IBM unit record equipment by IBM) like the ones in our collection (shown following this topic). Even when computers started to be used, most programming was done on punched cards and all computers had punched card input and output. It wasn't until the middle seventies at IBM that we internally switched from card input to CRT terminals. Figure 1 is a box of 2000 fresh punched cards just waiting for our machines to use. (When I programmed on punch cards at IBM, our programs consisted of several trays of cards, each try containing several of these boxes.)

Standalone card equipment ranged from simple devices like keypunches to primitive computer devices like the IBM 602 Calculating Punch which could do multiplication and division. All but the simplest card equipment could be "programmed" by wiring a control board like the ones shown here (often called a plugboard). Other than the fairly rare calculating punches, the most advanced card devices were accounting (also called tabulating) machines like the IBM 407 which read cards and printed a report based on the card data using some counters and simple branching logic (as defined by the plugboard program). These tabulating machines were the computers of their day and were pervasively used in business.

Accounting machines could also be used in non-obvious ways; in my first computer job in 1963 (application programming an IBM 7090 in Fortran and assembler), one of the scientists had programmed an IBM 407 to do matrix multiplication. (Here's a technical paper on this magic. Figure 2 shows a page describing the programming.) Later in college (1965-67) the computer we used (an IBM 1620) had only card input and card output. The output punched cards were hand carried from the computer to the 407 for listing. (The 407 was also used for many business tasks such as producing the student grade reports.) So, since every run I made ended up on the 407, I naturally learned how to program the 407 to do "cute", but useless things. We had lots of 407 boards, each preprogrammed with a particular application, similar to having multiple computer programs today.

Here is my collection of plugboards for IBM card equipment. Figure 3 is the board for an IBM 402 accounting machine, an earlier version of the 407, and Figure 4 show how the plugs come out of the other side.

When the plugboard is inserted into the machine, the plugs contact sockets that are hardwired to card read brushes, card punch controls, and internal counters and other logic.

Figure 4 also shows the label of what this program supposedly did (payroll). Figure 5 shows our four IBM 557 Alphabetic Interpreter plugboards. Since we actually have a 557 in the museum, having multiple boards allows us to have different programs ready to us. On the left side are some programming "statements" (plug wires) ready for more programming.

Figure 6 shows the plugboard for an IBM 088 Collator. Figure 7 shows the plugboard for an IBM 533 Card Read Punch. The 533 is particularly important as it was the input/output device for the IBM 650 computer, commonly considered to be the first mass produced computer. The 650 was the first computer I ever saw in person (on a high-school field trip to the engineering lab at UC, Berkeley), and it had a great influence on my later choice to specialize in computers.

Figure 9 shows the plugboard for an IBM 602 Calculating Punch. Figure 8 is a closeup of this board showing some of the controls for multiplying and dividing. Figure 10 shows our three plugboards for our IBM 514 Reproducing Punch. (Also shown are some programming plugs; these can be used on all the IBM boards.) Figure 12 show the control board for a rare device: the IBM 063 Card-Controlled Tape Punch. This device read cards and punched the corresponding values in paper tape.

Finally, Figure 11 shows a particularly rare piece: the control plugboard for an IBM 6400 Accounting Machine. This device is little know and I've never seen one (as opposed to all the other devices discussed in this section).

Figure 13 shows a new variety of a 402-403 control board. Note that Figure 3 shows our other 402-403 board and this new one is subtly different. Figure 14 shows a newly arrived control board for an IBM 85 collator. The model 85 is an earlier collator version that the Model 88 whose control board is shown in Figure 6. Note that the 85 board is much different (simpler) than that for the 88. It seems that every different version of the same type of device (collator, interpreter, etc.) had a different control board.

Finally, I now possess a IBM 407 control board. As described above, this is my favorite card devices and the epitome of card processing complexity. Figure 15 show the large (and heavy, about 25 pounds) 407 control board with an apparently working program. Figure 17 shows the label of the program which is "PAYROLL/CALC FICA/RETIREMENT/TAXABLE WAGES". This payroll application is a typical 407 function (our college 407 was used monthly for this very purpose). Figure 16 shows a close-up of some of the program's logic. The big orange and gray blob things are splitters and combiners of signals.

I'm getting too many of these to photograph them, so here is my inventory of IBM card equipment control panels: