Delphi For Fun Newsletter #20




Wednesday July 18, 2001
Delphi For Fun Newsletter #20
It's been a busy month - mostly grandkids and summertime stuff.   Oh, plus the new computer.  That old saying that 3 moves is the equivalent to a fire could be transformed for computers:  three upgrades is equivalent to any major disaster you care to name.   (Where are those old drivers?  What was that network parameter?  I know I solved that problem last year, why did it pop up again?  And how the heck did I solve it the first time?  Reinstalled Windows?  Don't forget all those updates.  Might as well bring all those drivers up to date while we're at it.)    Fun, fun, fun!
But I did manage to get a couple of programs written.  Here are the "What's New"  items since last time.   Enjoy.   

June 26, 2001:  We're  on a one week break between grandkid visits - just enough time to get some lawn mowing and garden work done.  For the past few days I've spent more time than was justified shopping for new PC pieces.   Components are now all ordered - $450 for an 800mhz Celeron system.  No mouse, hard drive or monitor, which I already have.  But including 256mb memory, a 9-bay mid-tower case, an 8X CDRW drive, 32mb AGP video card and a multimedia keyboard.    

The TAstronomy component & demo are working!  Sun, moon and planets all located in space and time.  (And those astronomer types have plenty of ways to measure both space and time.)   The project  turned out to be pretty large though,  4000 or so lines of code, so I guess it'll be a while before I get around to documenting and posting it.  If anyone is really interested in getting a copy "as is", send me a note.   

June 29, 2001:  Here's a little geometry/trig problem from an old ACM programming contest.    The FlatLand Piano Movers need a program to determine  if they can deliver a piano of a given size  around the corners at  a destination with hallways of known width.   I found it challenging, and never did find an analytical solution, although I'm sure one exists.  This program uses a "try it and see if it fits"  approach.  

July 14:2001:  The new computer is up and running.  For most of the stuff I do, I can't tell the difference between the new 800mhz Celeron and the old 300mzh AMD K5.  But I do have two 30gb hard drives mirroring each other now which was the main objective of the upgrade.  And the benchmarks say I'm 3 times faster so the programs should really fly out of here now.

Today I posted another simple Pi calculation program  - demonstrating the  relationship between the probability that pairs of integers are relatively prime and Pi.   We use Mr. Euclid's GCD  (Greatest Common Denominator) Algorithm to test "relative primeness", so I also posted a Math Topic on that remarkable result (see Euclid and the GCD).   I call it "remarkable" because he published his work a few centuries before algebra had been formalized!   By the way, if you ever need a real world example of why relative primeness matters, open your computer case and compare the number of blades on the CPU cooling fan with the number of fins on the heatsink.  I guarantee that the two numbers are relatively prime  (7 blades/ 12 fins  and  11 blades/16 fins on mine).  It's a resonance prevention thing.


July 17, 2001:  

"Howdy Y'all" LED sign

Scrolling LEDs -  a scrolling clock project that got out of hand.  You control message text, size, speed, color, etc.    Plus a dozen or so special downloaded LED fonts  (for which I take little credit).  

Well, I will take credit for fixing some font format problems.   Here's a new  File Fix-up program page from the Delphi Techniques section.  It describes the " extra carriage return" problem with a guess or two about the cause  and how to use the TFileStream component in a program to  fix it.  




"Contrariwise, if it was so, it might be;
 and if it were so, it would be;
 but as it isn't, it ain't. 
 That's logic." 
    -- Lewis Carroll

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