ASCII Programmer reference
ASCII Character Set | ASCII names table | Meaning of ASCII Control Characters
ASCII Chart
ASCII Character Set
This page shows a chart and table of the American Standard Code for Information Interchange (ASCII) character set. Each ASCII character has a corresponding 7-bit code; practically all modern computers follow this correspondence in their character displays. Note that the coding for ASCII characters runs from 00 to 7F (hex). Characters from 80 to FF (hex) (using an 8-bit code with the MSB set to 1) are not defined in ASCII. Use of these additional codes varies widely among computer systems.
Physical Device Controls: Format Effectors
- BS: Backspace
- HT: Horizontal Tab
- LF: Line Feed
- VT: Vertical Tab
- FF: Form Feed
- CR: Carriage Return
Physical Device Controls: Other
- BEL: Bell
- DC1, DC2, DC3, DC4: No assigned meaning in ASCII, but DC1 and DC3 are used for XON and XOFF in most software handshaking schemes.
Logical Communications Controls
- SOH: Start of Header
- STX: Start of Text
- ETX: End of Text
- EOT: End of Transmission
- ENQ: Enquiry
- ACK: Acknowledge
- DLE: Data Link Escape
- NAK: Negative Acknowledge
- SYN: Synchronous Idle
- ETB: End of Transmission Block
Physical Communications Controls
- NUL: Null
- DEL: Delete
- CAN: Cancel
- EM: End of Medium
- SUB: Substitute
Information Separators
- FS: File Separator
- GS: Group Separator
- RS: Record Separator
- US: Unit Separator
Controls for Code Extensions
- SI: Shift In
- SO: Shift Out
- ESC: Escape
Here's a nice trick for sending control characters. On most keyboards, rows 4 and 5 (or rows 6 and 7) of the ASCII chart are mapped onto rows 0 and 1 by way of a modifier key, usually the control key on a keyboard. For example, to generate a linefeed, press control-J; to generate a carriage return, press control-M, etc. look in the corresponding line of the same column in the table above. The Macintosh, PC, and Sun keyboards supports most of this mapping. On OpenBSD,
man ascii.
Source: Serial oscilloscope web tutorial, 1997, JC.
