Convert ASCII to ATASCII This converter uses the common text-oriented ATASCII mapping used by Atari 8-bit computers, keeping printable ASCII in its shared range while translating line endings and selected control codes.
Use it for Atari 400/800/XL/XE fixtures, emulator tests, and retro-computing text records.
Start with the built-in sample, then replace it with a short test value containing a space, punctuation, and a character whose code you already know. This gives you a quick sanity check before using a longer string.
ATASCII has special control, graphics, and inverse-video areas, so this tool is not a screen-memory encoder and does not pretend every ATASCII value has an ASCII equivalent.
Verify an ordinary letter and an EOL byte such as 9B against an ATASCII table before using a larger record. The result stays in the browser until you explicitly copy or download it.
This tool does not require an account, upload service, or external API. That makes it suitable for development checks, retro-computing exercises, documentation examples, and small repeatable test fixtures.
ATASCII was designed for Atari 8-bit computers and deliberately differs from standard ASCII in its control and graphics areas. Printable text overlaps substantially with ASCII, which makes simple samples look deceptively straightforward. The meaningful differences appear when you reach line endings or special control values. This tool highlights those differences rather than pretending the encodings are interchangeable.
The most useful example is the end-of-line marker. A normal ASCII line feed is not simply copied as byte 0A in a typical ATASCII text record; Atari text uses a dedicated EOL value. Seeing that mapping in the hexadecimal output helps explain why a text file can look correct on one platform and still behave incorrectly on another.
When creating Atari test data, keep the source text and expected hex bytes together. Start with a short phrase containing at least one space, one letter, and one line ending. Verify those bytes against an ATASCII reference, then expand the fixture. This turns an encoding question into a deterministic test rather than a visual guess.
This converter deliberately stays in the text-oriented part of ATASCII. It does not attempt to generate Atari screen memory, inverse-video graphics, or Atari ST character codes. Those systems and representations have different rules. Keeping the scope narrow makes the output easier to reason about and prevents a successful-looking conversion from being mistaken for a complete Atari graphics encoder.
For Atari-oriented test fixtures, record the source text and expected hexadecimal output together. That makes line-ending behavior and printable character mappings easy to check after changes to a parser or file writer. Because ATASCII contains platform-specific controls, a small verified sample is much more reliable than assuming that all ASCII text can simply be copied byte for byte.