The following message is a courtesy copy of an article that has been posted to comp.sys.ibm.sys3x.misc,alt.folklore.computers,bit.listserv.ibm-main as well.
[EMAIL PROTECTED] writes: > What I don't understand is pre sorting a deck that will be used as > input to the computer--couldn't the computer sort it faster than a > person could? The machine sorted strictly sequentially, while the > computer had bubble or shell sorts that were more efficient. maybe > tape sorting was slow, but disk sorting should've been fast. If the > machine had some core ie 128 k, then plenty of work could be done > within the CPU at very high speed. simple example would be fortran student jobs. the "master" of the program is the individual student's card deck. the student has access to only fortran compile & execution capability ... and compile would be one pass of the input card deck. when i started, the univ. had 1401 that was used as unit-record front-end to 709. the card decks (potentially multiple student jobs) would be collected in card tray. when the tray approached full (our every couple hrs), the tray of cards would be read by the 1401 and transferred to tape. the tape would be carried to 709 tape drive and processed (sequentially, each job compiled and executed) with output going to another tape. When processing finished, the output tape would be moved to 1401 and results printed. The operator would take the printed, fan-fold output, "burst it" ... i.e. tear it into individual jobs, match the bursted print output with corresponding original card deck, wrap the bursted print output around the input card deck (with rubber band) and place it in output bin for student pickup. there were some administrative jobs that used sort ... but that frequently had trays and trays of cards ... written to tape .. and then multiple tape sort (with intermediate tape files) that ran for extended period of time. i did write part of an application that was used for class registration. 2540 could not only read "holes" ... but also had the capability of reading "sense-marked" cards (i.e. no. 2 pencil marks in little boxes on cards). the 2540 had two feeds from the sides with five card stackers in the middle. one side read cards and could select two of the read-side stackers or the middle stacker, the other side punched cards and could select two of the punch-side stackers or the middle stacker. class registration had all these sense-marked cards ... which would read and place in the middle stacker. if the processing found some problem with a card ... a blank card from the punch side would be punched behind the recently read sense-marked card (with some problem ... before the next card would be read/processed) standard processing had an operator removing cards from the stacker and placing in card trays. all of the class registration sense-marked cards were plain manilla. the "punch" cards were loaded with cards that had yellow (or sometimes red) across the top band of the card. once all class registration cards were processed ... there would be multiple trays ... sporadically sprinkled with yellow top-edge cards ... clearly identifying the registration cards with some kind of problem. q&d conversion of gcard ios3270 to html http://www.garlic.com/~lynn/gcard.html reader/punch channel program command codes http://www.garlic.com/~lynn/gcard.html#23 system/360 model 30 machine room, 2540 is seen in middle, in front of the tape drives and partly obscured by 2311 disk drive. the "card reader" (feed) is on the right and the punch is on the left, the five output stackers are in the center http://www-03.ibm.com/ibm/history/exhibits/mainframe/mainframe_PP2030.html system 370 model 40 machine room, 2540 is in upper middle http://www-03.ibm.com/ibm/history/exhibits/mainframe/mainframe_PP2040.html better picture of 2540 on the right with somebody loading deck of cards to be read http://www.cs.ncl.ac.uk/events/anniversaries/40th/images/ibm360_672/slide19.jpg ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
