> It was Bad Practice not to have at least one hole punched in every channel.
Right! Had forgotten that! If a program skipped to channel 'n' and there was no 'n' hole punch the 14xx would perform a high-speed eject of an entire box of printer paper. Fun to watch, but earned the perpetrator the everlasting enmity of the operators. But you couldn't do all the "safety" punches on one line: it would weaken the tape too much at that point. You had to do kind of a "stairstep" of spare punches. Great illustration of tape and punch here: https://2.bp.blogspot.com/-IA1R-KQhpjg/UZm_OaHlLDI/AAAAAAAAFtI/sV4Ab7vugcs/s 1600/Carriage+Tape.jpg Thinking about what I wrote below, even though the tape was tough, it did not last forever. The holes were read with mechanical brass wire brushes IIRC, and eventually they tore up the carriage tape and it had to be replaced, usually at the most inopportune moment. Charles -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Paul Gilmartin Sent: Monday, January 16, 2017 10:39 AM To: [email protected] Subject: Re: Paper tape (was Re: Hidden Figures) On Mon, 16 Jan 2017 09:27:31 -0800, Charles Mills wrote: >It was exactly as shown in the Wikipedia photo. It was a very durable, tough, high-fiber paper, not at all the same as TTY punch tape -- other than the superficial similarity. After all, it made a trip around the sensors every page that the 14xx printed, boxes and boxes of greenbar every day. (Or every other page, perhaps. I seem to recall that there was a minimum length to the tape and it was not uncommon to make one tape loop account for two printed pages.) There was a special punch http://archive.computerhistory.org/resources/physical-object/ibm/102668343.l g.jpg, but I seem to recall that in a pinch one could use a loose-leaf or similar punch. > I recall visiting a site that had separate channel(s) for recto (and verso?) sheets in fanfolded paper. It was Bad Practice not to have at least one hole punched in every channel. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
