TDBS 1.2 - Controlling Time Slicing of Applications

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CONTROLLING TIME SLICING OF APPLICATIONS
----------------------------------------

CAUTION:  The information in this technical help note is for ADVANCED
USERS ONLY, and is NOT NECESSARY in the vast majority of situations.
eSoft Technical Support will not address questions about the information
in this tech note.

INTRODUCTION

TDBS provides undocumented controls which allow a sysop to tailor the
TBBS multitasker's attention to a running application.  In many
multitaskers, this type of control is called "time slicing."  With TDBS,
you can actually control the application based on time or by
instruction count.

These controls are placed on the Opt Data command line of a menu entry
which invokes a TDBS application.  When used, they will increase or
decrease the amount of system CPU resource the program will use.
IMPORTANT:  These switches are unique to TDBS, and will NOT work with
any other option module or TBBS function.

CONTROLLING BY TIME SLICE

Controlling an application by time slice is the default method used in
TDBS Version 1.2.  To specify a time slice, use the /QT:<x> switch,
where <x> is the number of milliseconds of desired time slice divided by
10.  For example:

        /QT:3

...would yield a 30 millisecond time slice.

Smaller numbers REDUCE system resource consumption, so the TDBS
application will run slower when the number is decreased.  THE TDBS
VERSION 1.2 DEFAULT IS /QT:4, RESULTING IN A 40 MILLISECOND TIME SLICE.

CONTROLLING BY INSTRUCTION COUNT

Controlling an application by instruction count was the default method
used by TDBS Versions 1.0 and 1.1.  You can force this method of control
by using the /QI:<x> switch, where <x> is the desired number of
instructions to execute on each pass.  For example:

        /QI:7

...would cause TDBS to execute 7 instructions each time the application
gets its "turn."

Smaller numbers REDUCE system resource consumption, so the TDBS
application will run slower when the number is decreased.  THE TDBS
VERSION 1.0 AND 1.1 DEFAULT WAS THE EQUIVALENT OF /QI:10, RESULTING IN
10 INSTRUCTIONS PER PASS.

Note that these are internal TDBS instructions, which do not have any
direct correlation to lines of program code.

USING THESE SWITCHES

If you wish to experiment with these switches, you must first understand
their effects.  As mentioned previously, using either switch with a
smaller value than the default will decrease the impact the TDBS
application has on the overall system performance, and will cause the
program to run slower.

Using a number greater than the default causes the TDBS application to
run faster, consuming more system resources.  As a result, the rest of
the system may run faster.

The effect of either switch on your overall system performance depends
on a variety of criteria, from disk loading conditions, CPU in use,
number of lines in use, modem speeds, etc.  Using these switches may or
may not have any impact on your system as a whole.  They will, however,
affect the performance of the TDBS application in question.

These switches were designed to test the internal capabilities of TDBS,
and should not be freely used in most cases.  Generally, they should
only be used in situations where a particular poorly written TDBS
application is consuming more system resources than desired.  You can
then "tame" the application by reducing its time slice.


TDBS0008
Rev.  4/94

Copyright (C) 1994 eSoft, Inc., All Rights Reserved.  Permission granted
to distribute this file in its entirety, without modification, to any
interested party.  Any other use requires the written permission of
eSoft, Inc.

IMPORTANT:  The information herein is subject to change without notice.
Please call or write to confirm factual information of importance to you
or your organization.

