Musical Instrument Digital Interface, - Hol.gr

multiple of each digit 1286432168421
binary counting system 1 0 1 1 0110
The binary number 10110110 is the equivalent of 182 in decimal. That is, (128 x 1) + (64 x 0) + (32 x 1)
+ (16 x 1) + (8x0) + (4 x 1) + (2 x 1) + (1 x 0).
multiple of each digit 256 16 1
hexadecimal counting system 1 A F
The hexadecimal number 1AF is the equivalent of 431 in decimal. That is (256 x 1) + (16 x 10) + (1 x
15). The multiples of the digits in the hexadecimal counting system are 1, 16, 256, etc.
So why do we have to learn all these numbers to understand MIDI?
Remember that MIDI digital information is transmitted using the binary system. The serial interface
translates musical actions or events into binary numbers that it receives and sends one at a time down a
MIDI cable. By understanding the binary counting system, we can look at MIDI information and
understand what is being transmitted through a MIDI cable. The binary number 10010000 is not easy to
calculate, but reading the number in the hexadecimal equivalent 90 makes more sense when it is applied to
a MIDI message.
10010000, 00110111, 01111011 = 90, 37, 7B, which may be interpreted as;
Note ON, MIDI channel 1, play the 55th note, at a velocity of 123 out of 127 possibilities.
multiple of each digit 1286432168421
binary counting system 1 0 1 1 0110
If we look at the binary number above there is an easier way to add up the number. Instead of counting the
binary number as (128 x 1) + (64 x 0) + (32 x 1) + (16 x 1) + (8x0) + (4 x 1) + (2 x 1) + (1 x 0) = 182
(Decimal), split the binary number into two sections.
multiple of each digit 8421 8421
binary counting system 1011 0110
hexadecimal counting system B 6
(8 X 1) + (4 X 0) + (2 X 1) + (1 X 1) = 11 or B in hexadecimal
(8 X 0) + (4 X 1) + (2 X 1) + (1 X 0) = 6 in hexadecimal
B6 hexadecimal number (11[B] x 16) + 6 = 182 in decimal
If we use eight binary digits we have 256 possible numbers. 00000000 to 11111111. We can use two
hexadecimal numbers to represent 256 numbers, 00 to FF. All MIDI events may be represented with eight
binary or two hexadecimal numbers.
You may download a document,Conversion of Numbers, that was created using the program Max. This
document compares the similarities between the decimal, binary and hexadecimal counting systems.By
clicking on the document your browser should download the file. The document may be changed back to