CA1 File

What are CA1 files and how to open them

Are you having problems opening a CA1 file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your CA1 files.

What is a CA1 file?

CA1 files have multiple uses, and Crack Art Bitmap is one of them. Read more about the other uses further down the page.

Crack Art Bitmap

Crack Art Bitmap (low-resolution) files store images created by Crack Art, a painting program for the Atari ST computer. Designed for digital art creation, these files capture color images at 320×200 pixels using a palette of 16 colors. They support optional compression to save space, and when uncompressed, hold raw screen memory data. Crack Art ran on Atari ST machines and used this format to write its picture files, which could be read back later for editing or display.

Files in this format begin with a two‐letter magic header identifying the format, followed by a flag indicating whether the image data is compressed or stored raw, and another byte specifying the resolution. The 16‐color palette follows, and then either the uncompressed bitmap data (which is always 32 000 bytes for the low-resolution mode) or a compressed stream using Crack Art's custom RLE-variant compression.

Internally, the magic is the big-endian word "CA". The compression flag is a single byte (0 for no compression, 1 for compressed), then resolution byte (0=low, 1=medium, 2=high). Palette size is 16 entries (each a 16-bit word) in low resolution; zero entries in high resolution. The bitmap is stored in planar format in low resolution, with the uncompressed case storing exactly 320×200×1 byte planes = 32 000 bytes of data.

How to open CA1 files

Important: Different programs may use files with the CA1 file extension for different purposes, so unless you are sure which format your CA1 file is, you may need to try a few different programs.

While we have not verified the app ourselves yet, our users have suggested a single CA1 opener which you will find listed below.

Last updated: August 25, 2026

All known file formats using extension .CA1

While Crack Art Bitmap is a popular type of CA1-file, we know of 2 different uses of the .CA1 file extension. Different software may use files with the same extension for different types of data.

Tales Runner Animation

We know that one CA1 format is Tales Runner Animation. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

Various apps that use files with this extension

These apps are known to open certain types of CA1 files. Remember, different programs may use CA1 files for different purposes, so you may need to try out a few of them to be able to open your specific file.

Help us help others

File.org helps thousands of users every day, and we would love to hear from you if you have additional information about CA1 file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.