Restrictions and Limitations (Windows Environment)
When defining function and control keys, beware of the following restrictions and limitations.
• The FRS has the following internal limitations: 40 program function (pf) keys, 40 FRS keys, and 25 menu items.
• The following control keys are reserved by the operating system for its own use and must not be mapped to any other operations: Ctrl+C, Ctrl+Q, Ctrl+S, and Ctrl+P.
Although Ctrl+P is trapped by the operating system before it reaches FRS, you can assign FRS objects to its internal designation, controlP, because controlP is mapped to the Sh+Tab key combination in the termcap file.
• FRS commands cannot be mapped to an FRS key. This is syntactically illegal because FRS commands and FRS keys both appear on the left side of the equals sign in the mapping statement.
• Positional menu item mapping cannot be turned off. You can see this if you look at the mapping file, for example:
menuitem1 = pf13 (Sh‑F3)
If you assign a FRS key to an activation block, that key's label appears on the menu line or in the Help Keys operation in place of the default key's label. The default key, however, still works.
"Go", key frskey5 =
begin
... [first menu item]
end;
In the previous example, both Sh+F3 and whatever is mapped to frskey5 triggers the Go operation, even though you only see the frskey5's label on the menu or in the Help Keys display. To deactivate this, you must assign another FRS function to the F key now assigned to menuitem1:
frskey10 = pf13 (Sh‑F3)
Normally, you must use an unused FRS key for this function.
• Currently, map files are the only way to turn off a function or control key (for example, controlV = off). Keys cannot be turned off by the Ingres/4GL or embedded query language set command.