








                           ConvertLX

                              V1.0

                          User's Guide


                        by John McDonald

                         Copyright 1998

                    Portions Copyright, 1995, 

                         The PAL Group






































Table of Contents

1.0 Introduction
2.0 Quick start
3.0 Using ConvertLX
 3.1 Overview
 3.2 Navigating
 3.3 Entering values
 3.4 Converting
 3.5 Getting help
4.0 Precision
5.0 Change History
6.0 Contacting the Author

1.0 Introduction

Welcome to the wonderful world of conversions! With ConvertLX, you'll
have at your fingertips the ability to translate between hundreds
of different measurements. Whether you need to figure out how many
square feet there are in that new 2.5 acre plot of land you bought,
or you're curious about what percent of impulse speed you're doing
down the highway, ConvertLX can provide the answers.

ConvertLX converts values in the following categories:

	Area
	Linear
	Liquid
	Speed
	Temperature
	Time
	Volume
	Weight

Within each category are various types of measurements. These include
all of the standard ones (metric, US, etc), plus a lot of older and
more obscure ones (haven't you always wondered how long Noah's Ark
was in meters instead of cubits?).

*** Disclaimer ***

I have made every possible effort to ensure that the data provided
by ConvertLX is as accurate as possible, and that the program functions
in a correct manner. However, it is impossible to ensure 100% accuracy. 
I accept no responsibility for any problems caused by the use of this 
program or the resulting data. Installation and use of this program
indicates acceptance of these terms. If you do not agree, please delete
this program from your system. 

2.0 Quick Start

In a hurry? Here's a fast introduction to using ConvertLX:

- Start ConvertLX

- Use the down arrow to select a category

- Tab to the From Value field and enter a value

- Tab to the From Units field and use the down arrow to select the
  units to convert from

- Tab past the To Value field to the To Units field and use the
  down arrow to select the units to convert to

- Press F9 to convert

3.0 Using ConvertLX

The following sections provide details on how to use the ConvertLX
utility.

3.1 Overview

To start ConvertLX, you can either change to the directory you installed
it in and type 'convert', or, if you added it to the system manager,
select the 'Convert' icon. For more details on installing ConvertLX,
please refer to the file 'install.txt'.

When you start ConvertLX, the main screen will appear. This screen
has five fields. Starting from the top, these are:

	Category

	From Value

	From Units

	To Value

	To Units

The Category field lets you choose which category of conversions you
want to do (Area, Linear, etc.). It has a pull-down menu of choices
that is activated by the down arrow. Use the up and down arrow to
highlight your choice, then press 'ENTER' to choose it.

The From Value field is an edit field that lets you enter the numeric
value you want to convert from. For example, to convert 150 miles
to inches, you would enter '150' here.

The From Units field lets you choose which units you want to convert
from. For example, if you're converting 150 miles to inches, here's
where you'd choose 'miles'. This field has a pull-down menu that is
activated by the down arrow. Use the up and down arrows and PG-UP and
PG-DN to select the from units, then press 'ENTER' to select it.

The To Value field is where the results of the conversion are
displayed. This is an edit field like the From Value filed, but
entering a value here wouldn't make a lot of sense. This field gets
filled in when you press the F9 key to do the conversion.

The To Units field is the same as the From Units field, except
it defines what units you want to convert to. In our '150 miles to
inches' example, you'd select 'inches' from the pull-down menu
for this field.

There are also three function keys. From left to right, these are:

	F1 - Help

	F9 - Convert

	F10 - Exit

The F1 key displays a help window. This gives a brief summary of how
to use ConvertLX, as well as a list of all of the various abbreviations
that are used to describe the units (i.e. 'sq' for square, 'met' for
metric, etc.). Use the up and down arrows and PGUP and PGDN to scroll
up and down in the Help window.

The F9 key tells ConvertLX to do the conversion. ConvertLX will check
to make sure you've entered a valid number in the From Value field,
and selected units for both the From Units and To Units fields. If
it finds a problem, it will display an error message. Pressing the
'ENTER' key will make the message go away, and put you back into the
field that has a problem. If no problems are detected, ConvertLX
does the conversion and displays the result in the To Value field.

The F10 key exits ConvertLX.

3.2 Navigating

The following keys are useful for navigating around ConvertLX:

   TAB - Used to move forward to the next field

   Shift/TAB - Used to move backwards to the previous field

   Down Arrow - Used to activate the pull-down choice menu in the
   Category, From Units and To Units fields

   Up Arrow, Down Arrow, PG UP, PG DN - Used to move up and down in
   the pull-down menus for the Category, To Units and From Units
   field. The pull-down menus wrap around, so if you want something
   near the bottom of the list, hit the down arrow, which puts you
   at the top of the list, then the up arrow or PG-UP to move 'up'
   to the bottom of the list.

   ENTER - Used to select the highlighted choice in a pull-down
   menu

   ESC - Used to get out of a pull-down menu without making a choice.
   The value in the field is not changed. ESC also dismisses the
   Help window.

3.3 Entering Values

There are two ways to enter values in the From Value field: 'normal'
numbers and scientific notation. The same two methods are used by ConvertLX
to display its results in the To Value field.

Normal numbers are just what they sound like - the numbers you use
every day. Examples are 1, 120, 2.345, and .55. When entering normal
numbers in ConvertLX, don't use any commas or other separators, other
than a decimal point (if needed). Also, except for temperature, negative
numbers aren't allowed.

ConvertLX tries to use 'normal' numbers to display its results. If the
numbers are too large or too small, however, it must use scientific
notation.

Scientific notation is a shorthand method of entering very large and
very small numbers without having to type a lot of zeros. A number
written in scientific notation has three components:

   - A base number

   - The letter 'E'

   - A power

The base number represents the part of the number you're willing to
type, the 'E' tells ConvertLX that the number is in scientific
notation, and the power defines how many places there are after
the decimal. For example, if you wanted to enter 123 billion
(123,000,000,000), you would type

   123E9

The 'E9' says to move the decimal 9 places to the right. In this example,
the decimal is implied after the number '123' (i.e. 123.0), so you would
add nine places to the right, filling them with zeros. You can also use
an actual decimal point in the base number. For example, if you typed
'1.23E2', ConvertLX would move the decimal 2 places to the right, giving
123. 

Very small numbers are similiar, except that the number after the 'E'
is usually negative. This means move the decimal to the left that
many places. For example, '123E-2' means move the decimal 2 places
to the left, giving 1.23 (remember the implied decimal - 123.0). Just
like large numbers, any empty places are filled with zeros. For example,
'1.23E-2' is the same as 0.0123.

3.4 Converting

To do the conversion, you have to select a category, type a valid
value in the From Value field, Select a From Unit from the pull down
menu, select a To Unit from the pull down menu, and hit the F9 key.
The resulting value will be displayed in the To Value field.

If ConvertLX detects any errors, it will display a window that
describes what's wrong. Just hit any key to dismiss the window -
ConvertLX will put the cursor into the field that had the problem.

Note that if you change one field after doing a conversion
(enter a different From Value, for example), you must press F9 to
re-do the conversion with the new value.

3.5 Getting Help

To get halp at any time, press the F1 key. This will display a
help window that describes how to use ConvertLX, along with a list
of abbreviations used in the unit descriptions. You can use the
up and down arrows and PG UP and PG DN to move around the help
window.

Press ESC to exit the help window.

4.0 Precision

ConvertLX uses a 'relative to base' method of conversion. This means
that data for all of the values are stored relative to some base
value. For example, all linear measurements are stored relative
to meters. This approach has the advantage of a significantly
smaller database (5.7K versus over 600K for direct one-to-one
conversions). However, the one disadvantage is that you loose
a small degree of precision. For example, to convert from feet
to inches, ConvertLX first converts feet to meters, then meters to
inches. This results in a small loss of precision - 1 foot will
convert to 12.034 inches, not 12 inches. The actual loss is pretty
small - less than 1/10th of 1% - and usually won't make any difference.
Also, the loss in precision diminishes with larger numbers. For
example, 100 feet converts to 1200 inches, not 1203.4 inches.

Another big advantage to the approach that ConvertLX uses, and
another reason for the loss of precision, is that there are no
floating point numbers involved. Since the x00LX has no floating
point processor, the program would have to include a floating
point software emulator if floating point numbers were used,
resulting in significantly larger memory requirements.

Also, please note that some of the units don't lend themselves
to exact conversions. This is a particular problem in the 'Time'
category. For example, ConvertLX assumes that a month has 30
days, even though some have 31 and February has 28 (or 29).
A year is assumed to have 365 days, even though a leap year
has 366. 

5.0 Change History

V1.0 - Initial release, August, 1998

6.0 Contacting the Author

If you encounter any problems or detect any conversion errors
(other than precision, as discussed above), please send me an
e-mail at johnmcd@ix.netcom.com. I'll try to answer you as soon
as possible.

Also, if you know of any measurements that aren't in ConvertLX,
send them to me and I'll try to include them in a subsequent
version.

John McDonald
August 1998