Wow! If I had 8000 punched cards, a binary merge sort would take
13 passes, or
about a second and a half per card. Sorting them by hand would
probably be
faster, ...
Faster, if you were good at reading punch holes. To get human-
readable annotation on the cards, you should have first passed them
through a different machine, an 'interpreter'.
I'd think that the old inverted radix sort (first partition by last
digit, then
next-to-last-digit, etc.) would be faster.
According to http://pattonhq.com/ibm.html [0] the key was to sort on
yet another machine, the 'sorter' [1], at a little under 11 cards/
second/column (and presumably one used radix sorts for multiple-
column or alphabetic keys)
-Dave
[0] it seems the collator was also clumsy, special-case-filled
hardware:
The collator was the most cursed EAM machine. Card jams were a
mechanical nightmare requiring partial disassembly to extract
mutilated cards. Read brushes were often ruined.
I note that one of the referenced parts in the collator manual is a
"joggle plate" on top of the machine, presumably for joggling the
card file against in the hopes it will subsequently feed smoothly...
[1] http://www.columbia.edu/cu/computinghistory/sorter.html
You may have heard the story of the operator who dropped a whole
box of cards. Wanting to put things right as quickly as possible,
he sorted the cards, without consulting the user. As it turned out,
that was the worst possible response. Up until that point, the box
had contained a sample of random numbers.
–Ted Powell, Dec 2006
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