|Dͻ
|D |5Diskovery |D
|Dͼ
^Cby
^CVal J. Golding

DEALING WITH THE SITUATION:
---------------------------
|9~3Big Blue Disk^N has received quite a bit of mail asking why we don't publish 
program source listings but instead present them in compiled form.  There are 
several reasons for this, including, first and foremost, the need to conserve 
disk space so that you the reader can reap the maximum enjoyment from what 
space we have available.  Secondly, with respect to BASIC programs, if they 
were not compiled not only would they run more slowly but we would require the 
presence of the appropriate BASIC interpreter.  Since there are several 
interpreters around and because we are not licensed to distribute them, this is 
not practical.  We are, however, working on a solution, and you may read about 
it next month in this space. 

This month's cover features |E~1Streets and Alleys^N, a solitaire game of some 
complexity.  From the basic program structure and design by managing editor |CDan 
|CTobias^N to the artful title screen and shuffle routines by |CJoel Rea^N, it stands 
as an outstanding example of collaboration between programmers.  It is 
interesting to note that Joel's title screen was created entirely with the PC's 
wide variety of text characters.

His original version using a little-known flag allowed the use of many colors 
and special effects but unfortunately, runs correctly only with a CGA color 
card.  Readers with other cards, which are detected by the program, will see 
alternate versions which omit some special effects.  This serves only to 
emphasize the wide-ranging incompatibilities between PC display cards.  
Readers interested in obtaining further details are encouraged to follow 
Joel's continuing series in his ^1IBM-PC Video Primer^N. 

Perhaps more significant, though, is the shuffle subroutine.  Computer card 
games are quite common, but most suffer from one major failing: the shuffle is 
handled by the random number generator.  On first thought, this might appear 
ideal, but if one takes the time to reflect, this is not so.  When a human sits 
down at a table and shuffles a deck of cards, there is an ordered starting 
point, most likely the sequence in which the cards from the last hand were 
picked up.  When a random number generator is used, this circumstance is never 
taken into account. 

Joel's subroutine starts with the cards in the order they would be when a fresh 
pack is opened, i.e., in sequence by suit.  A random number in the range of 23-
29 is selected and the pack is split at this point and randomly interleaved, 
exactly as it would be in a realtime shuffle.  When a hand has been completed, 
the cards are "picked up" in a specific order and shuffled, thus when a game is 
played nearly to completion, the following shuffle may contain a number of 
cards in sequence or near-sequence. 

The original routine was written in the COMAL language and translated to Turbo 
Pascal.  For the benefit of the hackers in our readership, we are twisting 
Joel's arm in the hope that the next issue of |9~3Big Blue Disk^N will see an article 
explaining his shuffle subroutine, along with a commented source listing.  If 
perchance it doesn't appear, write a nasty letter ... to him. 

CLAY PIGEONS:
-------------
Who among you is not familiar with the miniature clay man, Mr. Bill, and his 
near-fatal misadventures?  Some time ago, our sister magazette, |9~3Softdisk^N, 
presented an animated graphics series featuring a little stick man named 
|E~1Alfredo^N, who unfortunately developed a knack for stumbling into hidden tunnels 
and passageways while enroute home.  Recently, associate editor |CGeorge Leritte 
has been seen hunched over his computer, slaving to resurrect Alfredo for the 
benefit of |9~3Big Blue Disk^N readers.  Tune in now, and stay tuned. We're 
confident that Alfredo's adventures will amuse and entertain you for some time 
to come. 

When the Dow is down, stocks are up, or is it the other way?  Stockbroker/ 
programmer |CDavid Sparks^N puts your Wall Street knowledge on the line and 
suggests |E~1Taking Stock^N with a 20-Questions type quiz.  Also in this issue, we 
introduce ^1The PCjr Sector^0, an arena where jr owners can get together and learn 
more about their still-viable machine. 

This plus all of our regular |9~3Big Blue Disk^N features should be sufficient to 
hustle you over to the contents page and find out what we DIDN'T tell you. 
