Category : Alternate Operating Systems - Quarterdeck DesqView, CP/M, etc
Archive   : QWHITE13.ZIP

Output of file : DIRECTLY.TEC contained in archive : QWHITE13.ZIP

ID:WS Writing Directly to the Screen
Quarterdeck Technical Note #109 Filename: DIRECTLY.TEC
by Dan Sallitt CompuServe: DIRECT.TEC
Last revised: 2/13/92 Category: DV

Subject: This note answers the question: "How can I tell if my program writes
directly to the screen?" It also discusses how much memory to give
an application running in DESQview.

Q: How can I tell if my program writes directly to the screen? Or how much
memory it needs?

To tell if an application is writing directly to the video hardware inside
DESQview, make the following changes in the application's Change a Program

1) Set "Writes Text Directly to Screen" to N;

2) Set "Virtualize Text/Graphics" to N;

3) On the Advanced Options screen, blank out the following four fields in the
"Window Position" section: Starting Height, Starting Width, Starting Row, and
Starting Column. Put blanks in these fields, not zeros.

When these changes have been made, open the program. DESQview will place a
small window border on the screen; if the program comes up and stays within
the small window border, it does not write directly to the screen. If it
blows away the window border and takes the full screen, it writes directly to
the hardware.

Without Quarterdeck's LOADHI program, there is no reliable way to determine
how much memory an application needs to run other than by trial and error.
You can make a reasonable guess by adding together the size of the .COM or
.EXE file that starts the program and the size of its biggest overlay, but a
program's data storage needs are difficult to predict. The time-honored
method for determining the correct memory size for a window is to start by
giving the window an excessive amount of memory, then reducing that figure a
bit at a time until the program starts malfunctioning.

With LOADHI's /GS (get size) parameter, discussed in the QEMM and QRAM
manuals, you can get an accurate estimate of how much memory a program takes.
After you finish running the program with LOADHI, two numbers are returned:
the first is how much memory the program took to load and initialize, and the
second is the amount of memory the program permanently retained.

*This technical note may be copied and distributed freely as long as it*
*is distributed in its entirety and it is not distributed for profit. *
* Copyright (C) 1990-2 by Quarterdeck Office Systems *
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