Technical Notes Concerning Pointer Enabled Tools

This page contains technical details concerning PETs coding and other requirements.

Topics

  • What are the system requirements for PETs?
  • What workstations can be used?
  • What programming language is used?
  • What's the difference between emulator hotspots and how PETs respond to mouse clicks?

    • What are the system requirements for PETs?

    PETs require:

    In addition, each user must have at least a small, writeable "A" disk configured to his/her virtual machine.

    What workstations can be used?

    PETs should work successfully with any PC, Macintosh, or UNIX workstation which supports a 3270 emulator. But all emulators do not support configuring the mouse action in the way required to operate the PETs with mouse clicks. Please refer to the page on emulators for more information about "PETs-friendly" 3270 terminal emulators.

    PETs also work on fixed function 3270 terminals, but then the programs work like other 3270 applications, with keystrokes.

    What programming language is used?

    PETs are written in REXX and utilize the following standard VM/CMS components:
    1. CMS and CP commands
    2. CMS Windows
    3. CMS Pipelines
    4. Xedit

    What's the difference between emulator hotspots and how PETs respond to mouse clicks?

    Many emulators implement hotspots to enable more synergy between the emulator and the mainframe software. Hotspots are letters, words, or sequences of characters which have been predefined to the emulator. If those predefined characters are clicked on, then the emulator transmits those characters to the host or performs some other predefined action. Because emulator hotspots are defined in the emulation software, they must be defined at every workstation.

    PETs' hotspots are defined in the host software, rather than in the emulator. The emulator is not aware of any specific sequence of characters, but rather is aware only of the position of the pointer when the mouse button is clicked. PETs receive that information and determine what to do.

    While both of these strategies are valuable, the simple scenario described next demonstrates the benefit of the PETs approach.

    Several PETs implement menus. To select an item, you merely click on that item. To implement this control with emulator hotspots, each menu item would have to be defined in every emulator accessing that menu (dozens, hundreds, thousands of emulators?). If, one day, you decide to change the menu items, all those emulators have to be revisited. Using the PETs strategy, you change the menu only once, on the host.

    There's much more to come...stay tuned.

    --rick ellis

    Mail questions, comments, suggestions or inquiries to rge@uconnvm.uconn.edu .

    Page last updated on October 3, 1998.
    Copyright (C) 1998, Richard G. Ellis