Subject:      Re: Sequels to Alternate Reality
From:         paradise@netcom.com
Date:         1995/06/28
Message-Id:   
Sender:       paradise@netcom7.netcom.com
References:   <199506281405.KAA14499@postbox.acs.ohio-State.edu>
Organization: NETCOM On-Line Communication Services (408 261-4700 guest)
Newsgroups:   comp.sys.atari.8bit


In article <199506281405.KAA14499@postbox.acs.ohio-state.edu>,
Robert Rumpf  wrote:
>Just curious...The Dungeon was the last (and only) sequel released to AR:
>The City...but there were more modules in the works, right?  Like the ones
>you run smack into in the City:  The Arena, The Palace, The Wilderness,
>The Casino...any chance at all that these will ever be made?  I mean, is
>there a "Dungeon Creation Kit" for AR or is it all coded from scratch?
 The city had a poster size map printing and an interactive editing 
program I creating for development purposes. Also the atari 8 bit city 
allowed bootstrapping the sequels directly from the city without rebooting.
In order for someone to trick AR into believing that they had an arena, 
they would have to define a floppy the fit the expected format for arena 
and then AR city will blindly load into memory sectors from that 
disk(assuming again they all are properly formatted/structured) and then 
jump to a location in memory that is in the loaded area.

  Its been a long time(and I haven't booted my code disks) so I can give 
a foggy picture of the required data layout of a sector for the city and 
any other bootable sequel (This does not apply to the commercially 
released dungeon because the 
bootstrap feature was never implement on the c64 conversion of the city and 
therefore the dungeon did not have it).
But the layout went as follows:
Byte 1 & 2 Two integer values used for seeds for the encryption 
algorithm. The rest of the sector was encrypted including the header.
The order of the following bytes is not assuredly correct(Hey it's eleven 
years since I wrote it;D
Byte ID of which game in the AR series this disk is part of
Byte ID of which disk "side" in the game/sequel this is.
Track ID no disk (Used to prevent people copying sectors around to
see what that would do)
Sector ID on disk
Two byte checksum (this is the last thing, I believe it was two, not one 
byte)
120 Bytes of Data

Byte the way one flaw in my simple block-chain cipher I used is that if 
you have both seeds be zero, then the rest is the same(I think unless I 
added the last data value into the seed, ugh, been a while) as if 
there was no cipher:)[It used a simple xor and addition/modulo technique 
changing the working key as it went]. The encryption and decryption 
algorithm is also the first thing my VBI worm would consume if it was 
brought to life by someone flipping on Omnimon into memory.


-- 
                                             Philip Price
                                             paradise@netcom.com