[EMAIL PROTECTED] (Stephen M. Wiegand) writes: > I was trying to stay out of this thread because I thought it was a > homework or some other such question but having seen some of the > responses, I have an urgent need to add my thoughts. When I first > saw the question, I was thinking the person wanted to know how to > physically mount a tape. After all he didn't ask about JCL or a > program or a console command. That got me to thinking about how I > learned back in the barely light years. (They didn't have computers > in the dark ages). In my very first programming job we had an IBM > 370-?? CPU with DOS and Power operating systems. We didn't use tape > much in our shop but we had to get a drive because IBM in those days > sent everything out on tape. So we had some unit (don't remember > the numerals) that had two spindles and a sliding glass door. It > definitely had a vacuum load because you could hear it sucking when > you readied a tape. Having never been exposed to this hardware in > college and having to come in on weekends to load operating system > and other IBM software without the presence of an operator, I had to > learn how to "mount a tape". I remember you had to press a button > to open the doors, mount the tape reel on a spindle or hub (whatever > you call that thingy in the middle), thread the tape across the > heads and through another path. Press another button and the doors > closed, the vacuum sucked the tape up the rest of the way and onto > the take-up reel and readied the tape at the first readable block, > which might be the label if it was a labeled tape.
my first programming job was to implement a 360/30 version of 1401 mpio (rather than running 360/30 in 1401 emulation mode). the 1401 was used for unit record<->tape frontend for 709; loaded cards on tape, physically moved tape from 1401 drive to 709 drive, 709 ran outputing to new tape, took that tape from 709 drive back to 1401 tape drive and produced whatever print & punch output. tapes came in canisters which had to be opened, reel of tape removed. tape drives had full sized swing open doors that you manually opened; you had to mount the reel and then manually feed the tape to the tape-up reel (somewhat similar to the old audio tape open reel). later they had those straps that just wrapped around the reel of tape, instead of canisters that completely enclosed the reel. later still you got those straps that didn't have to be removed, there was new drives that would open the strap a smidgen and feed the tape from the reel. for the 360/30 mpio version i got to design and implement my own monitor, interrupt handlers, device drivers, error recovery, storage allocation, multitasking, etc. i could concurrently handle card to one tape ... while concurrently processing another tape to printer. recent posting with lots of references to MPIO activity: http://www.garlic.com/~lynn/2006b.html#0 http://www.garlic.com/~lynn/2006b.html#1 much later i had implemented a backup/archive system that i deployed on a number of internal systems (originally, mostly used 6250bpi tape). eventually it made it out the door as workstation datasave, which subsequently morphed into adsm and is now called tsm. http://www.garlic.com/~lynn/subtopic.html#backup the 360 green card had tape ccws. several years ago, an ios3270 of the green card was done (ios3270 was a full-screen menu app on cms from the 70s, lots of people saw it as the service processor menus on the 3090; the 3090 service processor was a pair of 4361s running a hihgly customized version of vm370 release 6 with all the menu screens in ios3270). the 360/67 "blue" card also had sense bit definitions for a number of devices. I had added some of that sense information (including tape) to the ios3270 gcard. recently i did a rough cut at translating the ios3270 gcard to html http://www.garlic.com/~lynn/gcard.html mag tape ccw: http://www.garlic.com/~lynn/gcard.html#25 sense data http://www.garlic.com/~lynn/gcard.html#17 picture of 2311 7mbyte disk drvies in the forground and a couple 2400 tape drives in the left middle (picture also drum in upper middle behind tape drives): http://ftp.columbia.edu/acis/history/2311.html the whole front of the tape drive was a door that opened. tape reel was mounted on the hub and feed thru the heads and onto the take-up reel. the reels had small finger indented finger depression ... you would wind the tape around the take up reel once (until it had overlapped and friction would keep it from slipping) and then you would spin the take-up reel several times (index finger in the finger depression) ... getting the tape position past the small strip of reflective foil that marked the start of tape. you closed the door and hit rewind/ready. that would spin tape from the take-up reel until the heads sensed the reflective foil (if you didn't get the tape spun manually past the reflective foil, all the tape would come off the take-up reel and you would have to feed it again from the start). the hub in the middle of the tape reel had a handle that pull out that released and/or locked the tape reel on the hub. earlier 701 tape drive http://ftp.columbia.edu/acis/history/701-tape.html later 3420 tape drive http://www-03.ibm.com/ibm/history/exhibits/storage/storage_3420.html the mounted tape is on the right with the (white) auto-strap still around the reel. this had a small clasp that the tape drive opened and pulled the tape thru the opening and fed the tape under the heads and onto the take-up reel. another picture of 3420 tape drive (on ebay, picture isn't likely to be around for long) http://cgi.ebay.com/Vintage-LIKE-NEW-IBM-3420-8-MAGNETIC-TAPE-DRIVE-Rare_W0QQitemZ5217468698QQcategoryZ74946QQcmdZViewItem here is a closeup of the white strap around a tape reel with the clasp on the left that could automatically be opened and feed the tape. http://ftp.columbia.edu/acis/history/media.html picture of 360/30 with tape drives on the left and 2314 disks on the right. http://ed-thelen.org/comp-hist/vs-ibm-360-30.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
