RE: "Field Mark" vs. "Duplicate" (Hex 1C)

in ASCII x'1C' = Field separator and used in communications of variable
length data. (POS credit card terminals) I don't know what it does in
5250 data stream.



Chris Bipes
Director of Information Services
CrossCheck, Inc.


-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx
[mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of James Lampert
Sent: Monday, April 28, 2008 2:37 PM
To: midrange-l@xxxxxxxxxxxx
Subject: "Field Mark" vs. "Duplicate" (Hex 1C)

One of our customers brought to our attention an example of a flat file
that used Hex 1C as a delimiter.

I'd never heard of Hex 1C (asterisk with overscore) being used in any
other context than the "Dup" key (shift-insert) on a terminal, but a bit
of research turned up references to "Field Mark" (which sounds like some
kind of delimiter), and to Shift-Home on 3270 terminals being mapped to
that value. I tried that keystroke on our 3489, and to my surprise, I
got an error of "Duplicate key or Field Mark key not allowed in field."
I tried it again in a field that I knew accepted a "Dup" keystroke, and
while I had no trouble getting "Dup" accepted, "Shift-Home" produced the
same message.

Does anybody here know what a "Field Mark" is, or why it shares the same
hex value and glyph as "Dup," or what kind of field actually does accept
it in 5250 data stream?