Actually, most farmers around the Rochester MN plant where most AS 400s were made farmed corn and vegetables. I lived there for a while.
South-central Minnesota is too hilly, too wet, and too warm to be good tundra.
They were very popular for a while. Admittedly, they were System 38s on steroids. In terms of common measures like processing power and address space size, they were at least mainframes.
It's a damn neat machine. I've not kept up with it, but in the 80's it was considered a "minicomputer," which meant it is a mainframe, just smaller. It's operating system, OS/400, was very solid -- crashes, data loss, etc. were virtually unheard of. It had separate subsystems for everything (communications, LAN, terminals, print spooling, etc.), which can be shut down, reconfigured, and restarted without re-booting the entire system, something I've seen mainframe people stare at in wide-eyed awe. It had built-in relational data base functionality in the microcode, not up in the applications machine-language layer. It used a huge virtual memory model, where everything (programs, data files, etc.) were considered to be in memory at all times -- any time one was needed, it just got swapped in by the virtual memory paging system. The more RAM it had, the better it ran.
Yeah. The Token-Ring Network actually natively used the IBM Cabling system, a star-based cabling system with 110-Ohm two-shielded-pairs cable and its own two-pair connectors. It ran at 4 Mb/sec, and got upgraded to 16. Ethernet those days was 10 Mb. The Token-Ring Network ran better than Ethernet when heavily utilized, but was just too damned expensive, and never caught on. It was marketed mostly at large corporations, and was intended for PC LANs, PC-to-mainframe connectivity, and anything else that would come along that needed local connectivity.
Twinax cabling was used for the 5250 family of terminals and printers used in IBM's minicomputers (System/36, System/38 (which evolved to the AS-400)). It used a screw-in twinaxial connector, and 150 Ohm two-conductor shielded cable. It could be adapted for the IBM cabling system (separate from a Token-Ring Network that would also be using it), as could the coax (RG-62, 92-Ohm) 3270 family of terminals used by the IBM mainframes.
Man, now THERE'S some trivia. Thought you might be interested.
Maybe his wife is also his landlady-- or did you mean "lessers"?
;-)
Best regards, Spehro Pefhany
--
"it\'s the network..." "The Journey is the reward"
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Hey, steady on old chap! I'm a consumer. Equipment made to suit my consumer needs may not seem quit so crap to me or other consumers. Perhaps it's crap to a pro but not to me!
But I'm not a pro and can't afford pro gear and probably have no need for something very highly specified.
There is one point which definitely has validity. Without checking, I recall that electrostatic charges can build up in the dielectric, and this causes a 'rustling' sound when the coax is bent. I believe that some coax - where this problem has been minimised - is specced specifically as being 'non-microphonic'. A Google is called for.
Yup, the search term you need is the triboelectric effect. It is a surface phenomenon that can affect dielectric materials. The usual cure in non-microphonic cables is a layer of moderate conductivity - usually thin and black - just inside the outer screen.
Yep. In extreme cases they use silver powder as well. It gets Expen$ive. Takes really expensive connectors. Mebbe over $100 a pop by now. Not to mention several $k for the tool kit and training to use them.
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