Guide to using 3270 consoles and terminals for Hercules

This is just scrawled notes at the moment. I may improve it sometime.
When the display fills up (and you haven't reconfigured the settings as shown below) you need to clear off the current messages before the system will continue. To do that type K (an abbreviation for the CONTROL command) and hit <Enter>. The line will be replaced by one saying 
    K E,1,9
which is the command to delete any unimportant lines between lines 1 and 9 of the display. Those lines will be marked with "|" characters at the beginning to show that they are unimportant and will be deleted. hit <Enter> to carry out the command and those lines will be wiped leaving more room on the screen. Some lines (including those beginning with "*" which signifies that they require operator attention) are "important" and will not be wiped. See lower down for how to get rid of these.
The console will, by default, use a group of lines somewhere in the middle for a "display". Various options of the DISPLAY command (abbreviation D) use this area for showing information. For example, the command D C,Kshows help information about the K (CONTROL) command options. Those lines then stay in that display area while other lines appear around it (meaning you have to clear stuff off more often). You can removed this display area with the command K E,D. You can then stop the display area from ever reappearing with the command K A,NONE. After that, commands which would have used the display area just scroll up information on the console as normal. This is useful for commands like D U (short for DISPLAY UNITS) which shows lots of lines of information about all the units connected to the system. Since I haven't figured out how to scroll the mini-display area by itself, I prefer just to get rid of it altogether.
You can reconfigure the terminal's display settings by typing 
    K S
which makes a pre-prepared line with the current setting appear, editing that line and hitting <Enter> to make it take effect. A convenient bunch of settings recommended by Jay Maynard is: 
    K S,DEL=RD,RNUM=19,CON=N,SEG=19,RTME=001
The "RD" is for roll-delete mode which means (maybe) that (some) unimportant messages will scroll off the top without explicit action. The "CON=N" means (I think) "conversational=n" and is similar to the option on the K N,PFK command below. It means that commands to clear messages off the top of the screen don't require confirmation. In other words, they don't cause another command to appear that you then have to hit <Enter> for again. Now you can use the command K by itself to wipe off all (unimportant) messages off the top of the console without needing to confirm it.
You can define a function for PF key num with a command such as 
    K N,PFK=(num,CMD='text'),CON=N
That means that hitting PFnum will have the same effect as typing the command text and the CON=N part means that the resulting command will be executed straight away rather than bringing up the text itself and waiting for you to hit <Enter>. A useful example is 
    K N,PFK=(1,CMD='K E,1'),CON=N
which at last gives you a way of getting those important "*" messages off the console. Each time you hit PF1 the message in line 1 will be scrolled off the top of the console, whether or not it is important or not. The command 
    D PFK
displays current PK key definitions. If you haven't done a K A,NONE to remove the display area then you can do D ...,L=Z to display them inline.

x3270 keys

In x3270 you can click on the little picture of a keyboard in the top right to bring up a button box of some of the common 3270 keys which aren't found on many non-3270 keyboards. You can also use the following equivalents for the keys which I find are commonly useful:
Reset
Alt-R
Insert
Alt-I
Clear
Alt-C
PA1
Alt-1
PA2
Alt-2
PFn
Fn
Author: Malcolm Beattie, <mbeattie@clueful.co.uk>
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