Thank you Tom!
On 06/12/2016 02:20 PM, Tom Brennan wrote:
Any program talking to the terminal (i.e. VTAM, Session manager, ISPF,
whatever) can ask the terminal for its capabilities and the terminal
responsds with a Query-Reply block, maybe a couple of hundred bytes
long, describing all the things the terminal can do. That includes
things like the alternate screen size (mod-3, mod4, etc.), whether it
can handle extended colors, underlining, graphics, etc.
I ran a real mod-4 green screen for many years, and it probably
returned the same block every time. And the guy nearby with the color
3279 probably returned the same block for that machine - every time.
But terminal emulators aren't stuck with the same hardware emulation,
so you can click options that will alter the Query-Reply. A typical
change is the terminal model, but an emulator could (although I don't
know why anyone would want this), simulate a terminal that say, can do
extended colors but no underlining. Who knows what that might do to
an application program that isn't ready for the odd combination though.
This book (chapter 6) has a list of all the replies if you want the
gritty details.
http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/CN7P4000/CCONTENTS
Here's an example of the returned data from a randomly chosen terminal
emulator:
0000 88001781 81010000 50001801 00D30320 "h..aa...&....L.."
"........P....+. "
0010 009E0258 070C0780 001181A6 00000B01 ".¦.8...+..aw...."
"...X.......ª...."
0020 00005000 18005000 18001681 86000800 "..&...&....af..."
"..P...P........."
0030 F4F1F1F2 F2F3F3F4 F4F5F5F6 F6F7F700 "411223344556677."
"(±±====(())÷÷˜˜."
0040 0D818704 00F0F1F1 F2F2F4F4 00078188 ".ag..0112244..ah"
".....=±±==((...."
0050 00010200 06819900 00001B81 85820007 ".....ar....aeb.."
"................"
0060 0C000000 00070000 0002B904 170100F1 "..........+....1"
"..........¦....±"
0070 03C30136 003F818F 0000E3C3 D7F3F2F7 ".C....a¦..TCP327"
".+.6.?....p++==˜"
0080 F040E5C9 E2E3C140 40400401 000025FF "0 VISTA ......"
"=@s+Gp-@@@....% "
0090 FF020600 00C0D59D 50000000 00000028 ".....{N+&......." "
....++.P......("
00A0 4E6F7420 79657420 6C6F6767 65642069 "+?+.`-+.%?++-+.-" "Not yet
logged i"
00B0 6E212900 000D8180 80818586 878899A6 ">.....a++aefghrw"
"n!)............ª"
00C0 A8FFEF "y.+ " "¿ n "
Another thing in there is the code page and character set used by the
terminal emulator, which can be picked up by the application program
and checked. For example, folks using code page 1047 might see SPUFI
give a warning that it likes code page 37 better. The 1047 SPUFI is
complaining about came from this pile of bytes - at location +6B.
----------------------------------------------------------------------
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to [email protected] with the message: INFO IBM-MAIN
