Tell the Difference Between These Three Pictures 1073
"rpl"
The programming courses taught to IBM customers were generally done by people in the IBM sales divisions, rather than the development or service divisions. I know that many aspects of "culture" differed between divisions. I never heard that the idea of which character to "slash" was one of them, but I would not be surprised.
As I mentioned previously, there was a corporate standard in IBM for handwritten characters, which called for slashing zeroes, as well as putting a horizontal bar at the base of the numeral 1, serifs at the top and bottom of the letter I, and just a straight line for the PL-I OR-bar. I don't recall whether or not it called for writing 7s in the European fashion with a bar across them. This is done in Europe to distinguish them from 1's, which people write with an extra angled stroke at the top.
On Sat, 11 Dec 2004 08:55:25 -0700, Anne & Lynn Wheeler Someone noted that it must be the AS-400, because the current one uses Power PC chips. I wouldn't have been sure, as perhaps some...
I recall that the IBM 1287 optical scanner, which read handwritten numerals, had both US and European versions due to this cultural difference. The little joke about the machine was that you wrote the machine-type number (which contains both a 1 and a 7) in either the US or European fashion to distinguish between the two models.
The idea of slashing zeroes goes back to the days of Morse telegraphy, well before the dawn of the computer age. As always, it was due to the need to remove the ambiguity between characters. That was particularly important when cryptographic ciphers were being used.
We've got a credit card ad over here where the narrator's got a puncture. He keeps saying 'pssent,' BBC announcers calling the Corporation...
In Morse, I suspect that the zero was the one that got slashed perhaps because it takes longer to transmit a zero in Morse than an Oh. (zero = dah-dah-dah-dah-dah, Oh = dah-dah-dah). But that's only a guess.
Another guess: the slashed Oh may have originated when some contrarian computer geek wanted to distance himself from the ham radio geeks. :-)
A lot of display terminals put a litle dot in the center of zeroes, including some from IBM. IIRC, the 2260 and 3270's did this. A less obtrusive, but still cleared up the difference. I don't recall anyone adopting this convention for handwriting, though.
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