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On 05/22/2018 05:12 PM, Grant Edwards wrote: |
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> The 3270 was completely screen-oriented. An entire screen was loaded |
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> from the host. That screen included fields with various attributes |
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> (e.g. editable vs. read-only). You could edit whatever was editable on |
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> the screen, and then when you hit "submit" the entire screen was sent to |
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> the host (there may have been an option to send only edited or editable |
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> fields, I don't remember the details). IOW, it worked vaguely like an |
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> HTML page containing a form. Except there were various entertaining |
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> ways things went wrong that don't happen with an HTML form. IIRC, if |
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> you inserted too much data into an improperly defined field, it could |
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> shift everything below it and muck up all the rest of the fields. I also |
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> seem to recall sometimes being able to edit fields that weren't really |
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> supposed to be editable, and then hilarity ensued when you hit submit. |
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I should have known / remembered that 3270 was screen oriented. |
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I've made the comparison to HTML forms multiple times myself. |
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Ya, the editable / non-editable setting was sent by the host and it |
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trusted that the client would not much with them. A number of mainframe |
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hackers have leveraged this (mis)feature before. |
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Some of the fields are similar to hidden fields in HTML forms. |
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> Though I did actually use some genuine IBM green-screen "3270-like" |
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> terminals, most of my experience was with 3270 emulators running under |
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> X11 -- so some of the fun was probably caused by bugs in the emulators. |
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Yep. |
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-- |
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Grant. . . . |
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unix || die |
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