5 Dumergue Avenue
						Queenborough
						Kent
						ME11 5BJ

Hello all,

	first of all, my sincere appologies to anyone who had problems
with UpdateCat in the last issue. Apparently, some people got the
alarming error message:

+++ Error 15 in line 95: Function not found
+++ Error 15 in line 62: Function not found
Command returned 10/15: Function not found

The problem was the function SHOWDIR(). My fault. I was foolish
enough to imagine that just because it worked on my setup it would
also work for everyone else. I'll try not to make that mistake again.

SHOWDIR() is defined in the ARexx function library "rexxsupport.library"
which is supplied as standard as part of ARexx. No functions can be
called from this library unless the library is made "available" to
ARexx. As I do this in my startup sequence, I sort of forgot that
others don't. Oops!

To rectify the problem, please add the following line to UpdateCat.rexx,
at around line 19, above "say ''":

call addlib("rexxsupport.library",0,-30,0)

This will make the library, and hence all of its functions, available
to ARexx, and UpdateCat will then work perfectly.

OK. Now back to the present. I've send in a few goodies for this disc.
These are a run-time library called "earth.library", a program called
"NumbersGame", and some tutorial stuff.

The "earth.library" is a run-time library which has extensive support
for string handling and binary trees, plus a couple of miscellaneous
functions dealing with exec lists and command-line parsing. It also
allows WB1.3 (or earlier) users to make use of standard AmigaDOS hooks
(which are normally defined under WB2.0). The binary tree handling
functions are extremely powerful, so do give the docs a read. The
documentation is extensive, and everything is described in great detail.
This library will of course work on all Amigas.

I wanted to write a program to demonstrate the use of "earth.library",
and also of my previous stuff ("earthrexx.library" and EarthMagic,
which have appeared on previous ACC discs), but I didn't want the
sort of "do nothing useful" programs which are normally supplied as
examples of usage. The end result is the program NumbersGame.

NumbersGame SOLVES the Channel 4 Countdown numbers game, and is
dedicated to my favourite TV personality, Carol Vorderman (who seems to
manage quite well without it). Readers outside of the UK may not have
heard of this excellent TV programme, but if you read the docs you'll
soon get the idea.

Full source code is supplied, so you can see how it all works.
NumbersGame makes use of the binary tree handling functions of
"earth.library", and also some of the string handling functions. It
also has a wonderful ARexx interface, thanks to the functions in
"earthrexx.library". It is also PURE, thanks to use of EarthMagic.

On an unaccellerated Amiga (like mine), NumbersGame is not quite
fast enough to solve problems within the obligatory thirty second
time limit. It does, however, solve them in less than a minute, and
usually takes around 45 seconds. An accellerated Amiga would solve
this problem (as would rewriting the software to be more efficient
but less readable).

Well, that's all from me. Sorry this letter is so boring, but I wrote
it in something of a hurry.

	Live long and prosper,

				Arcane Jill