Date   : Thu, 05 Sep 1985 06:57:42 EDT
From   : "Paul R. Grupp" <GRUPP@MIT-MC.ARPA>
Subject: Arf arf protection

Because of all the recent scare of "arf arf", "trojan horse", and "worm"
programs, I offer a secure environment to look at untested software in.
This program is offered in SOURCE only so YOU can see what it does.
Via FTP from SIMTEL20;

Filename                       Type     Bytes   CRC

Directory MICRO:<CPM.DSKUTL>
READONLY.LBR.1                 BINARY    3072  DFA9H

From the doc file;

... This program will set the disk system in a CP/M Version 2.x
operating system to read/only.  Once this program is executed the
only way to return the disk system to read/write is to do a system
reset (cold boot).  This "safety" is intended to prevent untested
software from changing any data on any disk.  This is useful even
if you know the software under test needs to write to the disk as
you can view the signon, menu, and any prompts until it does try to
write to the disk.  For example, if one of the menu options is to
display a directory, you can suspect that something is wrong if
this option tries to write to instead of read from the disk.  If
(and if when) a program does try to write to the disk a Bdos R/O
error message will be displayed and the program under test aborted.
...
    A more attractive test environment may be achieved with the use
of a ram drive that has a program to "install" itself.  If the
READONLY program is executed before the ram drive install program,
then the ram drive will remain read/write while all the other disk
drives in the system will be read/only protected.  This would allow
programs to write to the ram disk for testing, still protecting
data on the rest of the disks in the system.
...

Live long and prosper \\//
-Paul