4 base 64 encoding, 1 base 64 ready reckoner – Kramer Electronics SP-14 User Manual
Page 24
3.4
Base 64 Encoding
Base 64 is used as a compromise between compressing numeric values whilst still using
human readable ASCII characters. Base 64 is used by various internet protocols.
Base 64 is defined in “RFC 3548 The Base16, Base32, and Base64 Data Encodings July
2003” and is available on the internet at
The digits of base 64 are listed in the following table:
Table 1: The Base 64 Alphabet
Value Encoding Value Encoding Value Encoding Value Encoding
0
A
17
R
34
i
51
z
1
B
18
S
35
j
52
0
2
C
19
T
36
k
53
1
3
D
20
U
37
l
54
2
4
E
21
V
38
m
55
3
5
F
22
W
39
n
56
4
6
G
23
X
40
o
57
5
7
H
24
Y
41
p
58
6
8
I
25
Z
42
q
59
7
9
J
26
a
43
r
60
8
10
K
27
b
44
s
61
9
11
L
28
c
45
t
62
+
12
M
29
d
46
u
63
/
13
N
30
e
47
v
14
O
31
f
48
w
15
P
32
g
49
x
16
Q
33
h
50
y
The packets of this protocol have fixed length field for numeric data. They must be padded
with zeros to fully occupy the allotted bytes. From the above table it is noted that in base 64
the zero is the ASCII upper case ‘A’. In the section
3.4.1 Base 64 Ready Reckoner example
conversion of number may be obtained to assist in creating relevant conversion functions.
3.4.1 Base 64 Ready Reckoner
Here is a ready table showing the conversion between denary/decimal (base 10),
hexadecimal (base 16) and base 64 for the numbers between zero and five hundred. Base 64
numbers are padded to six characters. For shorter fields remove the leading ‘A’s.