P E R I O D I C 
===============

A program to display the periodic table and information about the 
elements for the Psion 3a. Version 0.3183...

(c) Anthony Kucernak, March 1994.   [ark1000@cus.cam.ac.uk]

This software may be distributed for free provided all of the 
following files are included and in tact:
Periodic.opa
Periodic.dbf
Periodic.pic

INSTALLATION
============
The software should be installed in a directory called \PERIODIC on 
any drive. It expects to find the database file (Periodic.dbf) and 
possibly a screen image (Periodic.pic, used for fast start-up - see 
below).

USE
===
Using Cursor Keys
~~~~~~~~~~~~~~~~~
Once the program has started it displays the periodic table. By using 
the cursor keys it is possible to move around the table.  If the 
cursor remains on one of the elements for more than a second, then 
information for that element is displayed in a scrollable window 
(SHIFT-cursor keys can be used to view all of the information within 
that window).  PSION-cursor keys can be used to jump to the edges of 
the periodic table.

Searching for elements
~~~~~~~~~~~~~~~~~~~~~~
By typing the characters that make up an elements symbol (Ru for 
ruthenium) it is possible to directly jump to an element.  As there 
are a number of elements which have as there symbol only one letter 
(e.g. O, oxygen; F, fluorine), you must be fairly quick about typing 
in the two characters otherwise the cursor will lock onto the first 
character. For instance, If you wish to jump to iron (Fe) and press 
F, but wait a little too long, the cursor will remain on F and 
display information for fluorine. If this happens you must start 
again. If you type a wrong character, press ESCAPE or SPACE to cancel 
the character typed. Once you have found the element you want, 
information on that element will be displayed in the window above the 
table.  You can scroll about that window using SHIFT-cursor keys.

Molecular weights
~~~~~~~~~~~~~~~~~
This program will determine the molecular weights of compounds typed 
in.  You should type them in pretty well as you write them.  The 
following notes should be observed:
-	You must type the characters as they appear in the periodic 
table. i.e. you must type the correct case of the letters. 
e.g. Fe and not FE or fe for iron
-	Numbers always follow what they refer to. e.g. K2PtCl6
-	You may use brackets (all of ({[<>]}) ) to include sub-
units e.g. Fe3(CN)6
-	Fractional stoichiometries are allowed e.g. WO3.33

THE DATABASE
============
The information for the periodic table is stored in a a database 
(periodic.dbf) in the periodic directory. To my knowledge the 
information is correct, although there may be some mistakes.  You can 
update or change the database by using the standard database 
application.  The fourth field containing the atomic weight 
information should not be moved in order as the program will complain 
(the molecular weight routine assumes that the atomic weights occur 
in the fourth field of the database).  
The program will accept up to 20 fields in the database.  I have 
filled in 17. Units for items in the database are assumed to be 
bracketed and stored with the field labels e.g. if you look at the 
field labels you will see that the fourth field is:
	Atomic weight(g/mol)
The program splits out the (g/mol) and places it after the units when 
it displays them.
If you find any errors/holes in the database please email me with the 
correct data so that I can correct it for the next release.

FAST START-UP
=============
On start-up the program checks to see if  the file 'periodic.pic' 
exists in the \PERIODIC directory, and if it does, it uses it to 
quickly display the periodic table.  If it does not find this file 
then it generates the periodic table (this takes slightly longer).  
It is possible to save this image for fast start-up by using PSION-I 
(save image).

THE FUTURE
==========
I hope to improve editing in the molecular weight section and also 
include a search algorithm for locating elements. (e.g. find elements 
with b.p. >= 1000K , <= 1500K and with a density <10 g/cm^3).  I'm 
open to suggestions for other improvements.

BUGS, SUGGESTIONS, BEER MONEY
=============================
If the program is of real use to you, then I wouldn't say no to some 
money.  If you find any bugs, or omissions/errors in the database, 
please email them to me.  I have not included source as I'm a little 
embarrassed.  If you want a copy, though email me and I'll see what I 
can do.

My address:	ark1000@cus.cam.ac.uk
		Anthony Kucernak