FS8M External MIDI Interface 1.0 p 4
be called "item number one" and the third "item number two." Programmers call this
process enumerating the items.
Why do programmers do this?
Here is an example:
If you are standing in front of your house, how far do you have to walk to get to your
neighbor? You have to walk ONE house unit away.
How far do you have to walk to get to your OWN house? Since you are already standing
in front of your house, you have to walk ZERO house units away.
Zero is the starting point, you move from zero some number of units.
Programmers frequently deal with lists of things. The same logic applies to these lists. If
you are looking at the first item in a list, how far do you have to move to look at the
second? You have to move ONE unit.
How far do you have to move to look at the first item? Since you are already looking at
it, you move ZERO.
Another way of looking at it is to ask the question, "How many single digit numbers are
there?" There are 10. They are: 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9. You don't get to the
number 10 until you add another digit. Programmers can't afford to be wasteful, they
use ALL of the digits, especially zero.
This is also the root of the controversy over the year 2000. If you start counting at zero,
2000 is the millennium.
MIDI is a computer communication protocol, and internally, it starts from zero.
MIDI Channels are actually numbered 0-15 and Program Changes are numbered 0-
127.
But, since most people are not comfortable counting from zero, MOST MIDI instruments
add an extra one and define MIDI Channels 1-16 and Program Changes 1-128. NOT
ALL MIDI instruments do this!
We debated long and hard over which philosophy to adopt. In the end we chose to
follow the de-facto standard and number from one. We believed that this decision would
result in less confusion and fewer problems.
One problem we could not avoid was the numbering of the MIDI Channel Selector
switch. The manufacturer of the switch numbered it from 0-15. These are in fact the
actual numbers the switch uses. We had no control over the labeling.
The unfortunate result of this mismatch is that you have to set the MIDI Channel
Selector Switch to 0 to select MIDI Channel 1.