Multi-Tasking

AMOS UNLOCK
instruction: re-activate toggle between AMOS Professional and Workbench
Amos Unlock

Use this instruction to restore the facility for flipping between AMOS Professional and the Workbench, via the [Amiga]+[A] keys.

AMOS HERE
function: report if AMOS Professional is currently at the front of the display
status=Amos Here

AMOS HERE is used to provide a simple report. A value of -1(True) is returned if AMOS Professional is currently displayed, otherwise zero (False) indicates that the Workbench is in view.

Communication between programs
As well as multi-tasking between AMOS Professional and other programs, communication is allowed between different AMOS Professional programs previously installed in memory.

PRUN
instruction: run a program from memory
Prun "program name"

This command can be used either from Direct Mode or from within a program, and it is a combination of calling a procedure and running another program. It is also extremely powerful! When PRUN is called, it has the following effect:

• A search is made through a program list for the specified program to be run, such as "Program_Name.AMOS".
• If it isn't found, this program is loaded and then tested.
• If an error is encountered, an exit will be made to the original program from which PRUN was called.
• If everything is in order, all variables are initialised, but the display is left unchanged. All screens remain open, with any windows and zones remaining defined. Opened files will remain open for AmigaDOS, but will appear to be closed to the new program. The new program is free to re-open these files.
• Bobs and Sprites are erased as the Object Bank is changed, and any music will be stopped. Banks may be passed between programs, however, and this is explained in Chapter 5.9.
• The new program will now be run.
• When the program is over, or if an error is encountered, an exit is made to the AMOS Professional program from which PRUN was called.
• All variable buffers are erased, all files are closed in the program that was called, and Objects and music will be halted. The screens will remain as they were.
• If the called program was not originally resident in memory but was loaded, it is now removed from memory.
• Control is returned to the original program, at the position immediately after the PRUN command.