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From: akcs.falco@hpcvbbs.UUCP (Andrey Dolgachev)
Newsgroups: comp.sys.handhelds
Subject: Protect for HP48 (attn: Bill Wickes)
Message-ID: <27b7409e:2013comp.sys.handhelds@hpcvbbs.UUCP>
Date: 12 Feb 91 01:40:04 GMT
Lines: 29

To Bill Wickes or anybody else who has or would like to take apart the
IFERR library posted by Mr. Wickes a few days ago:  I wrote a password
protect program for the 48 , using the IFERR library, but it is still
possible to kick out of the program by pressing ON repeatedlyery fast,
for about 3 or 4 times.  It would be a lot easier if somebody coudl
please post a message about how to disable the ON key (which is done in
the IFERR library) and/or how to disable the ON-C sequence.  In case
anyone is interested, the program which I made is pretty simple, and
takes up about 1.5 k or so (but only 700 bytes is really needed, if you
have intelligence).  There are four programs, TNOFF, whcih turns off the
calculator, and upon the subsequent  turning on, it asks for the
password.  The password can be up to 8 letters long, and the keys echo
PASSWORD, not the actual passowrd, aka bbs'.  If the right one is
entered, then the calculator is left free to use, otherwise, it beeps and
turns off.   The other three programs are NMESS, which creates a new
message to display (like name and phone number ) upon startup, above the
passowrd entry prompt, NPASS, which creates a new password, and INSTALL
which assigns TNOFF to the USERKEY OFF key.  The password and message are
stored in the hidden directory. As mentioned, it is possible, if you know
that you have to, to press ON a lot of times and kick out of the program.
 However, most casual users who cch your 48 unawares, will not be able to
use it.  If anybody knows how to disable the ON key, please respond.
           ----Falco

P.S.  Then again, who would leave a $250 calculator,especially iwht $60+
cards in it, lying around so people could try playing with it.  
P.P.S.:  Of course, how many people would even be able to use the 48 in
the first place, w/ or w/o passowrod protection.
P.P.P.S.:  Then again, Password protection on a calculator is neat.
P.P.P.P. S. Well, kinda'