Can the bit patterns used to represent characters represent other things in other contexts?
Yes.
You need to know the context to know what a particular pattern represents.
| Hex Char | Hex Char | Hex Char | Hex Char |
|---|---|---|---|
| 00 nul | 20 sp | 40 @ | 60 ` |
| 01 soh | 21 ! | 41 A | 61 a |
| 02 stx | 22 " | 42 B | 62 b |
| . . . | . . . | . . . | . . . |
| 0A lf | 2A * | 4A J | 6A j |
| . . . | . . . | . . . | . . . |
| 1E rs | 3E > | 5E ^ | 7E ~ |
| 1F us | 3F ? | 5F _ | 7F del |
The chart shows some patterns used in ASCII to represent characters.
(See the appendix for a complete chart.)
The first printable character is SP (space) and corresponds to the bit pattern
0010 0000 .
Space is a character, just like any other. Although not visible in the shortened chart, the upper case alphabetical characters appear in order A,B,C, ..., X, Y, Z with no gaps. There is a gap between upper case and lower case letters. The lower-case characters also appear in order a,b,c,...x, y, z.
The last pattern is 0x7F which is 0111 1111. This is the DEL (delete) character. For a complete list of ASCII representations, see the appendix.
How many of the total number of 8-bit patterns correspond to a character, (including control characters)? (Hint: look at the pattern for DEL).