In <[EMAIL PROTECTED]>, on 12/17/2005
at 05:54 PM, Chris Mason <[EMAIL PROTECTED]> said:
>The original paper says "TSO applications will now automatically use
>the larger screen size whenever needed.
That's false. In general, the application can only adapt to different
screen configurations if it has code to test for them. What is true is
that ISPF has such code, and has had it for a long time.
>What maybe it should have said was "TSO applications which are
>sensitive to variable screen dimensions will now automatically ...".
Not even that. They can use the larger screen size, but only if they
have the code to do so. Just doing a READ PARTITION - QUERY isn't
enough; they have to actually use the query response appropriately.
Normally a program written in REXX will not be able to accommodate
multiple screen geometries. In order to do so it must use an external
package for terminal I/O, e.g., ISPF, installation-written fullscreen
function package.
IAC, a program intended for use with a 3270 protocol must avoid any
text characters at the same code point as a 3270 order, e.g., 7E. It
should use such values only whaen they are3 intended to be 3270
orders.
>In order to check this out, if you can see in the REXX clist where
>the first output data stream is written, you should ensure that the
>"Erase Write" command is the first byte rather than the "Erase Write
>Alternate". With the standard IBM-supplied mode table entry,
>D4C32XX3, "Erase Write", 0xF5, instructs the display microcode or the
>emulator programming that the screen is to have 24 rows of characters
>in 80 columns
I believe that D4C32XX3 allows the terminal to set the primary screen
size to other values.
>while "Erase Write Alternate", 0x7E, instructs the display microcode
>or the emulator programming that the screen is to adopt whatever is
>the maximum of which it is capable.
No, it sets it to the alternate screen size, which can be smaller than
what the display is capable of. As far back as the 3180 there were
3270 terminals that the user could set to a restricted screen size.
--
Shmuel (Seymour J.) Metz, SysProg and JOAT
ISO position; see <http://patriot.net/~shmuel/resume/brief.html>
We don't care. We don't have to care, we're Congress.
(S877: The Shut up and Eat Your spam act of 2003)
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