Release time after shell?

[Mike Doty]

If shelling to a Windows program is it
a good idea to pause or release a timeslice
to Windows? I have a program that sometimes
locks up after shelling and changing screen modes.

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[Lance Edmonds]

If you are using WINLINK, then the DOS process is suspended anyway, so there should be no problem.

If you are launching a GUI app directly from a SHELL (which is launched as a separate process), then releasing time slices in the DOS app is probably a good idea, but that should not cause the GUI app to lock up.

Are you using ULTRASHELL or anything else like that?

The following is a commentary on timer slices:

A DOS app should always release time slices when running under Windows. ie, if it is sitting in a 'wait' loop (wait for a keypress, wait 1 seconds, etc). It's the "nice" way to write an application.

I have actually had a couple of folks ask me why one of my (now very old) DOS apps needed 100% CPU when waiting for the user to make a Main Menu selection! Not a smooth look.

Now I know better...

For the lurkers here, you release a time slice while waiting for a keypress like this:

    IsWindows% = istrue bit(pbvHost,8)
    if ucase$(environ$("OS")) = "WINDOWS_NT" then IsWindows% = -1
    ...
    while not instat
        if IsWindows% then
            ! push DS
            ! mov AX, &H1680
            ! int &H2F
            ! pop DS
        end if
    wend
    a$ = inkey$

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Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

[Mike Doty]

I can't seem to duplicate the problem now.
Anyway, not using any other shell program.
I'm going to release some time slices.
Thanks for the fast response!

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