3 on numbers – Matrix Orbital PK202-25 User Manual
Page 38
q¥r¢QRB£BI(7G7st¢`E$¡1"r¢QB£B1u¢v¡¢"Ib©%¥9£4¢"hegf
q¥r¢QRB£BI(7G7st¢`E$¡1"r¢QB£B1u¢v¡¢"Ibwyxwegf
8.3 On Numbers
Like all computerized devices, the display operates with commands and values in the form of binary
numbers. These binary numbers are arranged in 8 digit (i.e., 8 bit) groups called bytes. The decimal value
of a byte may have any value from 0 to 255.
Bytes are usually specified in either decimal or hexadecimal (base 16) form for convenience, since binary
numbers are confusing to deal with directly. Hexadecimal (hex) numbers are particularly convenient because
exactly two hexadecimal digits make up one byte, each hex digit representing 4 binary digits (4 bits) as shown
here;
Table 20: Hex Value Table
Binary Hex Decimal Binary Hex Decimal
0000
0
0
1000
8
8
0001
1
1
1001
9
9
0010
2
2
1010
A
10
0011
3
3
1011
B
11
0100
4
4
1100
C
12
0101
5
5
1101
D
13
0110
6
6
1110
E
14
0111
7
7
1111
F
15
Based on the table, the byte 01001011 can be represented in hex as 4B, which is usually written as any
of 4Bh, 4BH, 4B hex or 0x4B.
The numbers can also be expressed in decimal form if preferred.
8.3.1 ASCII Characters
Since computers deal internally with numbers only, but externally with both letters and numbers, several
schemes were developed to ‘map’ written characters to numeric values. One such scheme has become
universal, the American Standard Code for Information Interchange, or ASCII. ASCII tables are readily
available from a number of sources. A few examples will do here:
Matrix Orbital
PK202-25
34