This is an old revision of the document!
Table of Contents
Ctrl-A (Attribute) Codes
“Control A” codes (a.k.a. ^A codes) are terminal control sequences embedded in Synchronet text and menu display files.
Background
Ctrl-A codes are primarily used in place of ANSI X3.64 terminal escape sequences to control terminal text attribute (e.g. color) combinations and perform some cursor positioning and other advanced features (not available with ANSI escape sequences).
The advantage that Ctrl-A codes have over ANSI escape sequences is that they are easily stripped out or converted by the Terminal Server of the BBS software to automatically meet the capabilities of the remote user's terminal. There are additional capabilities in Ctrl-A codes that go beyond the realm of terminal control and ANSI escape sequences.
The Ctrl-A character was chosen because it's a control character not often found in displayable text files or expected to be rendered in a consistent manner on all terminals. And “A” is for “Attribute”. 
Ctrl-A codes may be included in most text files displayed to users of the Synchronet Terminal Server as well as messages posted in message bases, extended file descriptions, and other places where some colored text can give users the opportunity to better express themselves.
Use
Ctrl-A codes are 2-character sequences which begin with a Ctrl-A (ASCII 1) character (hence the name) and are followed by a single character (case insensitive) which determines the operation to be performed. The only exception to this 2-character sequence is the Ctrl-A“filename code, which takes a filename as an argument and the filename is considered part of the sequence and not displayed.
It can sometimes require a special purpose text editor to actually enter a Ctrl-A character into a text file. Some editors may require a special key sequence or use of a menu option to enter a Ctrl-A character into a file. The graphical representation of the character may be a happy face or any other non-alphanumeric symbol that the editor chooses to render to represent that character code. There are @-Codes for the equivalent of many of the Ctrl-A codes, so may consider using them if they are more convenient for your text editor of choice.
In the text.dat and possibly some other files (e.g. JavaScript and Baja source files), Ctrl-A characters may be included by using the escape sequence \1 (or \x01) rather than having to insert an actual control character into the file.
The ANS2ASC utility may be used to convert files encoded with ANSI X3.64 terminal escape sequences (e.g. *.ans) into Ctrl-A encoded output and the ASC2ANS utility can be used to perform the opposite operation (useful for editing Ctrl-A encoded files (e.g. *.msg or *.asc) with an ANSI-BBS screen editor).
Colors
The following table is a list of Color Control Ctrl-A codes and their purpose:
| Color | Foreground | Background |
|---|---|---|
| Black | K | 0 |
| Red | R | 1 |
| Green | G | 2 |
| Yellow/Brown | Y | 3 |
| Blue | B | 4 |
| Magenta | M | 5 |
| Cyan | C | 6 |
| White/Gray | W | 7 |
Attributes
The following table is a list of Attribute Control Ctrl-A codes, and a brief description of each code's usage:
| Attribute | Code | Description |
|---|---|---|
| Bright | H | High Intensity foreground |
| Blink | I | Blinking (slow), when supported by the terminal |
| Bright-Background | E | High intensity background (so-called iCE colors), when supported by the terminal (new in v3.17c) |
| Blink-Font | f | Set the Blink attribute only if a alternate Blink-font has been activated in the terminal (new in v3.17) |
| High-Blink-Font | F | Set the Blink attribute only if a alternate High-intensity Blink-font has been activated in the terminal (new in v3.17) |
| Normal | N | No Special Attributes (Normal, e.g. light-gray) - resets both High and Blink attributes |
| Optimized Normal | - | Only changes to normal if High Intensity, Blinking, or Background attribute is set (or pop attributes if pushed) |
| Optimized Normal | _ | Only changes to normal if the Blinking or Background attribute is set |
High Intensity and Blink
The High Intensity console attribute behaves as it does with ANSI terminals: that is, once enabled, the current color and any subsequent new colors will be rendered in their “high intensity” (bright) version. To revert to normal/dark colors, a Normal (or Optimized Normal) Ctrl-A code must be specified. The Normal attribute code will reset both the High Intensity and the current color - back to the default, “light gray”.
The Blink console attribute behaves similarly: once set, all newly-printed characters will have the blink attribute until a Normal attribute code is encountered.
Control
The following table is a list of Terminal Control Ctrl-A codes, and a brief description of each code's usage:
| Operation | Code | Description |
|---|---|---|
| Pause | P | Display a Pause (e.g. [Hit a key]) Prompt |
| Pause Reset | Q | Reset the line counter for the auto screen-pause function |
| Delay | , | Delay for one tenth of a second |
| Delay | ; | Delay for one half second |
| Delay | . | Delay for two seconds |
| Cls | L | Clear the screen and home the cursor |
| Home | ` | Home the cursor (without necessarily clearing the screen) |
| Clreos | J | Clear to end of screen (leave cursor in current position) |
| Clreol | > | Clear to end of line (leave cursor in current position) |
| Bckspc | < | Send a non-destructive backspace character (Ctrl-H) - Cursor Left |
| CR | [ | Send a carriage return character (Ctrl-M) - Cursor to Beginning of Line |
| LF | ] | Send a line feed character (Ctrl-J) - Cursor Down |
| Cond-Newline | / | Send a new-line sequence (CRLF) only when the cursor is not already in the first column (new in v3.17) |
| Cond-Linecont | \ | Send a line-continuation sequence (text.dat LongLineContinuationPrefix line) if terminal < 80 columns |
| Cond-Blankline | ? | Send a blank-line sequence only when the previously printed line was not blank (new in v3.17) |
| Push Attr | + | Save current attributes into (server-side) attribute LIFO stack |
| Pop Attr | - | Restore attributes from stack (or Optimized Normal, if no attributes saved/pushed) |
| SOH | A | Send an actual Ctrl-A (ASCII 1) character |
| SUB | z | Send an actual Ctrl-Z (ASCII 26) character (note: lowercase 'z' only v3.17c and later) |
| EOF | Z | Premature end-of-file (note: uppercase 'Z' only in v3.17c and later) |
| Cursor Right | 128-255 | Move cursor to the right (code-127) characters |
Macros
The following table is a list of Macro Ctrl-A codes, and a brief description of each code's usage:
| Macro | Code | Description |
|---|---|---|
| Date | D | Display the current system date (in “MM/DD/YY” or “DD/MM/YY” format) |
| Time | T | Display the current system time (in “HH:MM am” or “HH:MM:SS” format) |
Advanced
The following table is a list of Advanced Ctrl-A codes, and a brief description of each code's usage:
| Operation | Code | Description |
|---|---|---|
| Sync | S | Synchronize node status and output with terminal (i.e. initiates a call to nodesync()) |
| Embed File | "filename | Display contents of filename from the Terminal Server's text directory |
Security
Synchronet also supports Secure Control Ctrl-A codes which may be used to hide text from users not meeting certain security criteria (i.e.: Security Level or Flags from Flag Set #1).
The following table is a list of Security Control Ctrl-A codes, and a brief description of each code's usage:
| Code | Description |
|---|---|
| Ctrl-A thru Ctrl-Z | Only display the following text to users with the corresponding flag A through Z turned on (from Flag Set #1) |
! | Toggle the text display off/on for users of less than level 10 |
@ | Toggle the text display off/on for users of less than level 20 |
# | Toggle the text display off/on for users of less than level 30 |
$ | Toggle the text display off/on for users of less than level 40 |
% | Toggle the text display off/on for users of less than level 50 |
^ | Toggle the text display off/on for users of less than level 60 |
& | Toggle the text display off/on for users of less than level 70 |
* | Toggle the text display off/on for users of less than level 80 |
( | Toggle the text display off/on for users of less than level 90 |
) | Restore the displaying of text to ALL users |
