Everyone pull that Write Punch and Silver patches and a box of cards..Grins
. On Dec 2, 2015, at 12:33, J O Skip Robinson <jo.skip.robin...@sce.com> wrote: One urban legend (not necessarily fiction) is an explanation for the curious layout in EBCDIC coding. We have A - I as C1 - C9 J - R as D1 - D9 S - Z as E2 - E9 Of course there is one more hex value in the neighborhood than there are letters in English, but why jump from D9 to E2 instead of using E1 - E8? The story I heard in computer school is that the EBCDIC ultimately derived from the punch card layout. To represent a letter, a card required both a 'zone' punch in one of the first three rows at the top plus a 'digit' punch further down in the same column. The first group of letters used the top zone row and so on through the alphabet. The last group of letters worked off the third zone row. The story goes that early punch equipment and card stock were imprecise and flimsy. In order to avoid having to deal with two vertically adjacent punches--third zone row plus first digit row--the code was constructed to skip the 1 digit for the letter S. Since a gap was needed anyhow, this was the ideal place for it. I love this story too much to challenge it. . . . J.O.Skip Robinson Southern California Edison Company Electric Dragon Team Paddler SHARE MVS Program Co-Manager 626-302-7535 Office 323-715-0595 Mobile jo.skip.robin...@sce.com -----Original Message----- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of Paul Gilmartin Sent: Wednesday, December 02, 2015 8:34 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: (External):Re: What's a "ton" of JCL? [was:RE: Straightforward way to determine hardware architecture level?] > On Wed, 2 Dec 2015 10:02:01 -0600, Dana Mitchell wrote: > >> On Tue, 1 Dec 2015 23:03:59 +0000, J O Skip Robinson wrote: >> >> (This whole season feels like Friday.) A doughnut, on the other hand, >> requires the hole for its very definition. The hole supplies no mass or >> nutritional value, but without it the thing is not a doughnut. By contrast a >> punch card requires the solid part to give the holes meaning; they would >> otherwise collapse into gibberish. > > In school we verified that if you multi-punch every possible punch out > of a card, the result is indeed very fragile. But it was fun to dupe > This could inspire a Retro engineering project: Given the constraint of required mechanical strength, devise an encoding that maximizes information density. Akin to GCR: https://en.wikipedia.org/wiki/Group_code_recording (How much does the hole diminish the mechanical strength of the bagel?) -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
