IBM Card Sorters deal cards from a source deck into 13 output pockets (one pocket for rejects plus one pocket for each of the 12 rows on the card) at the rate of 250-2000 cards per minute, depending on model. One column, selected by the Sorting Brush, is sorted per pass. The Selector Switches determine which row(s) in each column are included in the sort. To fully sort a deck of cards required a number of passes through the sorter; one pass per column in the sort key. Sorters normally did not have a control panel (plugboard), but Type 75, 80, and 82 sorters had a tiny one if they were equipped with the optional Multiple Column Selection Device. Click on images to enlarge:
I'm not sure when the Type 75 hit the market but it was after 1928 (when the Type 71 was introduced) and no later than 1935, since a photo of one appears in the Baehne Plates, fifth plate. Most if not all of the models from the 1900s, 1910s, and 1920s were vertical to save floor space. Here are the dates and speeds of selected models:
Original Census Sorter
70 Vertical Sorter
71 Vertical Sorter
Type 75 Model 1
Type 75 Model 2
80 Model 1
Type 80 Model 2
For some reason, IBM didn't produce a card reader that operated at 2000 cpm. The 084 was unique in that it used a vacuum-assist card-feed mechanism that did not require the use of a card-weight, as the cards were held against the throat and picker knives by suction. The 084 also used an optical method of detecting card punches instead of the wire brush used by earlier models.
The 082 sorter was the first machine CE's received training on when I started with the company in 1966, even though my main assignment was to be with System/360 I/O and CPUs. Training on Sorters and Keypunches (024, 026, 029) was standard for CE's. They familiarized everyone with punched-card concepts, and also served as a kind of 'boot camp' to see who would survive into more advanced schools.
An interesting historical footnote to the origins of sequence numbers in columns 73-80: This practice started because the on-line card readers for the 704, 709, 7090 and 7094 computers read cards only in 'row binary' format, reading cards row-by-row into 12 pairs of 36-bit words (2x36=72). The reader was not capable of reading more than 72 of the 80 columns of a card, so early compilers and assemblers, such as Fortran and FAP, could only 'see' those 72 columns. Row binary was converted into BCD character codes via software. A wire-jumper control panel in the reader selected which 72 columns were input, but of course the 'default' was to use one that was wired for columns 1-72. The remaining columns, being ignored, were a good place to put sequence numbers as 'deck-dropping insurance'. Later systems for source-code maintenance exploited the sequence numbers as a method of identifying card-images, in systems where all 80 columns were readable, such as when jobstreams were transferred from card to tape, typically by using an IBM 1401.
In the course of trawling for material for a talk on the early days of computing in my particular subject area I have just been reading your very helpful material on the IBM 082 sorter (and related mechanical devices). It brought back memories (few of them fond) of wrestling with this beast in the early 1960s.
You don't mention it but I wonder whether you ever came across the tip for dealing with a dropped deck of non-sequence-numbered cards. This was always to draw with a soft felt-tip pen one or more diagonal lines across the top of the deck. While this did not give the exact sequence position of every card it reduced the number of possible arrangements from n-factorial to something that just might be manageable.
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|Columbia University Computing History||Frank da Cruz / firstname.lastname@example.org||This page created: January 2001||Last update: 2 June 2022|