TUNDRA

Latest revision as of 02:57, 28 December 2023

TUNDRA is one of several systems for expressing text-mode graphics using text characters and control characters setting positions and colors. ANSI Art was the main system of this sort, but a few others were invented during the BBS era.

The ansilove (and Ansilove-C and ansilove.js) open-source software can display TUNDRA among other formats.

[edit] Identification

TUNDRA files start with a byte of value 24 (decimal), followed by the ASCII string TUNDRA24.

[edit] Format

More details of the format can be seen in the Ansilove source code (e.g., the function tnd in ansilove.js).

After the header, the file consists of a series of literal text characters (any that are not one of the few recognized control characters or the numeric parameters following them) and control sequences.

Most numbers are 32-bit unsigned big-endian integers. Color palette values are 24-bit RGB arrays.

Characters 1, 2, 4, and 6 (corresponding to Ctrl-A, Ctrl-B, Ctrl-D, and Ctrl-F) are the recognized control codes.

Character 1 is followed by two integers (32-bit) setting the new x and y cursor positions. 32 bits are rather overkill since these are setting positions on an 80 x 25 screen.

Character 2 is followed by a 24-bit RGB array to set the foreground color.

Character 4 is followed by a 24-bit RGB array to set the background color.

Character 6 is followed by two 24-bit RGB arrays to set both the foreground and background color.

[edit] Software

• Ansilove

[edit] Sample files

• blocktronics_block_to_the_future.zip → TCF....tnd
• dexvert samples — image/tundra