[TUHS] UNIX on S/370

arnold at skeeve.com arnold at skeeve.com
Tue Nov 21 18:09:28 AEST 2017

Grant Taylor via TUHS <tuhs at minnie.tuhs.org> wrote:

> Ya....  From what (little) I know about 3270 (and 5250 for AS/400s?) 
> reminds me of HTML forms with the mainframe as the web server and the 
> terminal as the client web browser.  What with the mainframe sending 
> [protected,hidden] fields to the terminal that displayed them and 
> trusted what the terminal sent back.

Also from what little I know, that's a decent analogy.

> *headshake*  Times were different. 
>   I am guessing that there is also security through obscurity based on 
> what information was available at the time.

Bear in mind that said terminals were wired directly to the peripheral
controller, usually within the same building, in cable conduits under the
floor, in the ceiling overhead or in various combinations thereof.  It
wasn't TCP/IP over wireless!

Moving the interaction with the human into a peripheral made a lot of
sense; you often had dozens or hundreds of the terminals hooked up to
the mainframes, and the interrupt per single-character model of Unix
and other minicomputer OSes would have brought a mainframe to its knees,
crying like a baby.


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