From: pjs@ariel.ucs.unimelb.EDU.AU (Peter John Swiatkowski)
Newsgroups: misc.forsale.computers
Subject: Re: WANTED: Phone Book USA CD-ROM
Date: 16 Dec 1992 17:10:31 +1100
Organization: University of Melbourne
NNTP-Posting-Host: ariel.ucs.unimelb.edu.au

In article <1249@consult.UUCP> bob@consult.UUCP (Bob Willey CDP ) writes:
>In article <1gbphoNN7m4@smurf.sti.com> westes@smurf.sti.com (Will Estes) writes:
>>I want to buy the 3-volume set Phone Disc USA, sold by DAK among others.
>>This set lists business and residential addresses and telephone numbers
>>in the U.S.  If you have a set for sale please contact me by mail.
>>
>
>You might want to do some more checking before you buy something.
>We recently ran into a problem that many of the CD's with major lists on
>them are "restricted" to a certain number of inquiries and after that 
>you have to pay "per thousand" for additional usage.  A real bite.
>
>Not sure if the one you mention has this restriction, but you may want
>to check BEFORE you buy.  I think the most recent one we ran into was
>the American Business List.  Limited to something like 1500 inquiries.
>
>-- 
>>.. Bob Willey, CDP          ..  |  ..  uunet!consult!bob  bob@ccs.com   ..<
>>.. CCS Enterprises, Inc.    ..  |  ..   Office: (410) 820-4670          ..<
>>.. P.O. Drawer 1690         ..  |  ..      FAX: (410) 476-5261          ..<
>>.. Easton, Maryland 21601 ......|......... BBS: (410) 476-5098 ...........<

I have had a brief experience with an Australian phone disc similar to the
one described.

I believe that the installation procedure encodes some sort of counter in
some obscure location on the hard disk of the system concerned.

In experimenting I found that the software would not install on a floppy
disc only system - unintelligible installation errors occurred - even there
was sufficient space for the required files. It was possible to install the
phone software on another system and the inquiry count would start at the
original value. Deleting the software and reinstalling it on the same
system left the counter as it was just prior to deleting the software.

The gist of this is that either a conter file is being installed on the
system (I did not check at the time and no longer have the cd-rom) or it is
being written to some otherwise unused portion of the hard disk. If the
former then deleting the file and reinstalling the software should give you
a fresh 1500 (or whatever) inquiries. If the latter then it will probably
require a low level format of the hard disk to destroy the hidden counter.

It's apparent that the CD-ROM disc itself is not being written, so some
non-volatile storage medium must be involved. The local system hard disk
seems the only likely suitable candidate.

If anyone plans to try to define the method used I would suggest that a
complete hard disk backup of the system concerned be done prior to installing
the retrieval software, since the changes effected by the installation
routine may also be backed up. Use of a checksumming routine (common in 
many anti-virus programs) to check for changes to individual files may be 
a help.

If anyone one knows anything more about the mechanisms used I - and I
suspect other readers of this group - would be interested in the specifics.

Peter Swiatkowski
University of Melbourne
Victoria, Australia
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