REDD.SYS (Version 1.0) Copyright (c) 1992 Douglas Boling
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First Published in PC Magazine September 15, 1992 (Utilities)
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REDD.SYS:

REDD is a Remote Executable Device Driver that allows you to execute
programs on a LAN server just as if you had entered their commands from
the server keyboard. REDD is easy to install and is compatible with
DOS-based LAN programs such as NetWare Lite and LANtastic. However,
heavy-duty server programs such as Novell's NetWare, which replace DOS
when they run, are incompatible with REDD.

Apart from compatibility, there's another reason why REDD was
designed for the smaller LAN environment. PC LAN servers are usually
fast 486 machines with huge disks and lots of memory. In a large LAN
installation, the server will be kept busy just handling user requests
for disk data and printer services. Moreover, in a corporate environ-
ment LAN security is often paramount, so LAN administrators can't give
users access to the server. On small LAN setups, however, there are
only a few users and all of them know the system. Here, an ultrafast
server usually idles along, wasting vast CPU power that REDD could turn
into higher productivity.

To construct the executable file from the source code requires an
assembler compatible with Microsoft's MASM 2.0.

USING REDD

REDD is installed the same way as any other device driver--by adding
a line to the server's CONFIG.SYS file. The full syntax for REDD.SYS is

DEVICE=[d:\][path\]REDD.SYS

Once it's installed, REDD looks like a small (2,560 bytes) RAM disk
to the server. In addition to the line in your CONFIG.SYS file, you must
make any configuration changes necessary in the server's LAN program to
allow the various LAN stations to access the REDD disk. This two-step
process completes the installation.

To use REDD, you must first create an ASCII file that consists of a
list of commands to be executed, in order, by the server. This command
file must be named KEYBOARD.IN. It is similar to a simple batch file,
except that it lacks such specialized batch commands as GOTO. A sample
KEYBOARD.IN file is shown below in Figure 1.

All you need to do now is copy the command file to the REDD disk.
As soon as REDD sees that a KEYBOARD.IN file has been copied to it, it
sends the contents of the file to the server's BIOS keyboard buffer.
To the server, therefore, it appears as if you were simply typing in
the commands directly on the server's keyboard. After processing the
KEYBOARD.IN file, REDD erases it.

If REDD is in the middle of processing a KEYBOARD.IN file from
another user, the new KEYBOARD.IN file will overwrite the file that is
currently being pro~cessed. To avoid this danger, you should first
determine whether a KEYBOARD.IN file is already on the REDD drive before
copying a new file to it. A simple DIR inquiry will suffice.

Because you may have to include nonstandard characters--function
keys, for example--in your KEYBOARD.IN file, REDD provides a method to
pass these keystrokes to the server. The keycodes used to send these
non-ASCII keys consist of the scan code of each key plus 80h. For example,
to pass an F10 keystroke to the server keyboard, you would put byte C4h
in KEYBOARD.IN. (The scan code for the F10 key is 44h, which, when added
to 80h, equals C4h.) REDD subtracts the 80h and places the remainder
in the scan code portion of the keystroke. The scan code, along with a
zero for the ASCII field, is then stuffed into the server's BIOS keyboard
buffer.

REDD is not designed for applications such as word processing, where
you need to interact continuously with the screen. It's designed to
speed the execution of compilers and the like, which produce output files.
At the same time, when your commands execute you do need to be able to
see the server's response on your monitor. Thus, on its RAM disk, REDD
creates a read-only file called SCREEN.OUT. This file stores the last
1,024 bytes of data printed on the server's screen. Note that REDD
captures screen data written using the BIOS video services only, and not
that which an application might write directly to the screen. You can
TYPE the SCREEN.OUT file to see it on your display, or copy it to your
disk and call it up from there.

One warning is in order. Although ANSI.SYS uses the BIOS routine
to write to the screen, it does not use the carriage return and line-feed
characters to terminate each line. REDD makes an attempt to interpret
screens written under ANSI.SYS correctly, but it is sometimes unable to
capture them perfectly.

Aside from the files KEYBOARD.IN and SCREEN.OUT, the REDD disk acts
like any other RAM disk. Small files can be copied to and from it, though
you must remember that any files copied to the REDD disk will take up
disk space that could be used for a KEYBOARD.IN file.

DOUGLAS BOLING IS A CONTRIBUTING EDITOR TO PC MAGAZINE.
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SAMPLE KEYBOARD.IN FILE

rem
rem Comments can be inserted in KEYBOARD.IN files, COMMAND.COM
rem ignores REM statements. Think of the KEYBOARD.IN file as a
rem script file you would pipe to a program.
rem

rem
rem Assemble REDD using server's CPU. Directories are specified from the
rem server's point of view because I don't know the server's PATH.
rem

c:
cd \projects\redd
d:\lang\masm\masm redd;
d:\lang\masm\link redd;
c:\dos\exe2bin redd redd.com

rem
rem You can also use FOR statements, just remember to use only one % sign
rem

for %a in (*.bak) do del %a

rem
rem IF statements can be used, but GOTO statements don't work.
rem

if EXIST *.tmp del *.tmp

rem
rem The following statements show how to enter a program and exit
rem using a function key.
rem
rem NOTE! Once we are in WordPerfect, we can't use REM statements.
rem They only work when talking to COMMAND.COM. The graphics character
rem is an F7 to exit WP.
rem

d:\wp\wp c:\temp.fil
Now is the time for all good men to come to the aid of their country.

Temp file long name
doc

y

rem
rem Back to COMMAND.COM
rem
type c:\temp.fil

del c:\temp.fil

Figure 1: The KEYBOARD.IN file contains a list of commands to be executed,
in order, by the server.
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