CONFIG.CTL
Device Driver

Michael J. Mefford
1988 No. 20 (Utilities)


Purpose:A device driver that lets you modifiy your CONFIG.SYS file while
the system is booting up.

Format:DEVICE=[path]CONFIG.CTL m
[Configuration
entries to be
controlled]
DEVICE=CONFIG.END

Remarks:CONFIG.SYS command lines to be edited or bypassed must be placed
between the DEVICE= lines shown above. The m parameter sets the number of
seconds CONFIG.CTL pauses before continuing with an unmodified normal boot-up
sequence. Pressing any key (except Esc) during this pause brings up a
point-and-shoot menu of the editable CONFIG.SYS commands.

The Up and Down Arrow keys move the menu highlight bar between the
various editable command lines; PgUp and PgDn move the bar to the first and last
lines, respectively. Pressing F1 deactivates (or re-activates) the highlighted
command. F2 accepts all changes and boots up. Pressing Esc bypasses all
CONFIG.CTL actions.

The highlighted line can also be edited, subject to two limitations.
First, no completely new line may be added; and second, the number of characters
in an existing line may not be increased (it may be shortened). For editing,
the Left and Right Arrow keys and the Backspace key are supported; Home and End
move to the ends of the highlighted line. The editor operates in overstrike
mode. Examples:

BUFFERS=003
DEVICE=THIS IS A PLACE SAVER
DEVICE=ANSI.SYT

The above BUFFERS line will permit a subsequent increase to 999. The
two DEVICE= lines will give harmless error messages normally, but permit
substituting a new device driver and loading ANSI.SYS by changing a single
letter.

Changes made using CONFIG.CTL affect only the current session; they do
not permanently modify CONFIG.SYS. If not set, the m parameter defaults to 0
(no pause), bypassing the prompt. The CONFIG.CTL program can still be activated
in this situation, however, by pressing any key (except Esc) immediately
following the boot-up beep.

CONFIG.CTL is already compiled and ready to run. If you prefer,
CONFIG.BAS will create CONFIG.CTL when run once in BASIC. The .ASM source code
listings are also downloadable, but require you to use a macro assembler (IBM or
Microsoft Version 2 or later).

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