Punched cards (Was: 1" paper tape buy ?

M H Stein dm561 at torfree.net
Thu Mar 5 15:30:48 CST 2009

--------------Original Message:

Date: Wed, 4 Mar 2009 14:39:41 -0800 (PST)
From: Fred Cisin <cisin at xenosoft.com>
Subject: Punched cards (Was: 1" paper tape buy ?

Does anybody object to changing the subject line?

My father used to claim that the only reason for existence of the
round-hole, 90, 96 column cards was that IBM patented the particular
rectangular shape of their holes.

He also claimed that IBM patented the whole idea of using a brass roller
for card reading, and that that ALMOST worked to cripple the rest of the
industry, until somebody finally got photocell card reading working.


IBM did indeed patent the rectangular holes used in their 80 column
cards. Whether the brass roller was a major factor is questionable;
after all, their competitors also used punched cards.

But there's no question that the general acceptance of IBM's card
format and their locked-in customers were instrumental in IBM 
becoming the giant that they did; while their competitiors struggled 
during and after the depression, punch card sales helped IBM survive
and grow. As late as the mid-fifties punch card sales represented
30% of IBM's bottom line; see:


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