If you benefit from the website, in terms of knowledge,
entertainment value, or something otherwise useful, consider making a
donation via PayPal to help defray the costs. (No PayPal
account necessary to donate via credit card.) Transaction is
If you shop at Amazon anyway,
consider using this link.
We receive a few cents from each purchase.
The index page for all
Programs on the site?
The DFF Play CD?
DFF Play CD.zip contains executable version of about 75
of the 200+ programs from the site, mostly those I particularly liked or
thought would be of widest interest for non-programmers. The file
is rather large, about 20mb..
Not a programmer (yet)?
That's OK - the executable version
for any puzzle or game you find here is available for download.
Just scroll down to the bottom of most any description page and you'll
find a "Download executable" link. Downloaded programs are in
"zipped" format to reduce size and may require an "unzipper" program
unless you are running Win XP or later.
Here's a link
to a free one.
Check out the
Most Popular Downloads from DFF
First time visitor?
Take a look at the
Introduction page to see what this site is about
January 8, 2012
Fun Newsletter #62
Best wishes to all for a happy and
prosperous new year!
We had a good holiday season. I
now have a new stack of books to work through in the coming months in case real
winter ever arrives. It looks like program production slowed in the past
quarter most likely because the programmer (me) is slowing down. The two
posted in December were pretty satisfying though; first, an dragstrip timing
tree simulator which drives an external relay board to operate a physical
tree built by one of our viewers. The second is an earth satellite
simulator. One of the books in my unread stack is "An Introduction to
Celestial Mechanics" so I hope to tackle multiple interacting orbital bodies
In the meantime here are the new
posting in the last quarter of 2011.
October 14, 2011: We're back home from a short hiatus
visiting a grandson at college, Williamsburg Colonial village, Jamestown,
Yorktown, and the Virginia Sate Fair. A Yorktown, I picked up "The
Campaign That Won America, The Story of Yorktown" by Burke Davis and I've found
it fascinating reading even though there is not an equation or puzzle in it.
The main takeaway for me: the French played a crucial role in winning our
independence from evil old Britain. I may have to reconsider my opinion of
posted another update today to a program included in our
Wordstuff program, Unscramble this
time. I added an option to handle cases where, rather than being
scrambled, words are "interlaced". Letters for 2 or 3 words appear in the
correct order but interspersed with letters of the other words. A
new checkbox on the Unscramble form indicates that the letters represent
interlaced words. The sample set of 17 letters included on the form
represents 3 synonymous words in a puzzle from a recent Mensa Puzzle Calendar
page. I did not successfully identify the words using human brainpower,
but the program finds them in several ways in a minute or two.
October 21, 2011: Scrambled
Letter Blocks was posted today in our Delphi Techniques section. The
puzzle is from the October 17 page of my
2011 Mensa 365 Brain Puzzlers Calendar
"Form six 9-letter words by combining two 3-letter
blocks below with each ending already placed in the grid. All blocks will be
used. If you do it correctly, one of the vertical columns will spell a bonus
word. Use these groups to complete the words in the grid:
AFT, ARC, BET, DEM, ERG, HEN, KEB, ROT, SCO, SNA, UND, YST"
October 30, 2011: A batch (command line)
version of our Clear Blank
Lines utility program was posted today to help a user who needs to run the
program repetitively. The program removes lines from user selected text
files which are entirely blank. Batch files can be a pain in the "you-know-what" to
set up but are an convenient way to repetitively run a program without user
interaction. Parameters in this version allow masked
searches for files to be processed including ability to search subdirectories,
and to make backups of files which are changed. The download includes
sample test files and a batch file to process them.
November 10, 2011: If you are into search
algorithms, here's one,
Branch and Bound, which demonstrates "Exhaustive" and "Branch and Bound"
search methods for finding the
best solution for "Knapsack" problems. It was adapted with the author's kind
permission from the book "Ready-to-Run Delphi 3.0 Algorithms", Rod Stephens,
Wiley Computer Publishing. The Knapsack Problem requires that we figuratively fill a knapsack by
selecting from a set of items whose
weight (or other "cost" measurement) and value (or "profit") are known.
The objective is to maximize the value (profit) of the items in the sack without
exceeding a predefined weight (cost) limit. The "Branch and Bound" method
is orders of magnitude faster than Exhaustive search for large cases.
November 13, 2011: Another small feature
upgrade for our Brute Force Solver program today. In
Brute Force Version 2.6, you can specify
the allowed solution integers as a range ( for example. 1-5 instead of
1,2,3,4,5. Today's Mensa Calendar Puzzle "Alphametics"
problem is also
included in the sample problem download files as a test case.. Just enter
NOW+NOW+NO=CHOW into the program to find the answer.
November 30, 2011: The Four Fours problem
requires that digits 4444 be combined with mathematical operations to form
expressions which evaluate to all values from 0 to 100. I couldn't do it
using +,-,*,/,^ operations (other "cheats" are required). I did generalize
the problem so that my Four
Fours version does find 4 digit solutions for smaller target ranges or 5
digit solutions for all 101 targets..
December 4, 2011: The original Drag Strip
"Christmas Tree" program simulates the sequenced lights used to control drag
race starts. I recently enhanced the program to drive real lights on a
real model tree using a USB relay board for a drag car owner and
enthusiast. . See
Dragster Tree Relay
Version 2 for more details
A satellite with
initial altitude of 1000 miles and 15000 mph
velocity will circle the earth in 100 minutes at altitudes from 1000 down to
100 miles above surface
December 18, 2011: Whew! It has been a busy month between
deer hunting, Christmas preparations, and educating myself about how satellites
manage to orbit the earth. A decent little 4 point buck is in the
freezer, the Mission style bookcase for the wife's scrapbooks finished,
and Earth-Sat Satellite
Simulator Version 1 was posted today.
Of the three activities, the
simulator took the most time by far, but I now have a pretty good handle on how
and why satellites manage to stay in the sky. I'll be checking and
cleaning up the documentation in the next day or two, but I believe the
program is in pretty good shape.
Age is an issue of mind
over matter. If you don't mind, it doesn't matter. ~Mark Twain
Growing old is mandatory;
growing up is optional. ~Chili Davis
Men do not quit playing
because they grow old; they grow old because they quit playing. ~Oliver
To subscribe or
unsubscribe from this newsletter, visit
369,000 visitors and
283,700 program downloads in the past 12