Extract text from data files (ADDISM)
To convert ADDISM files to another format, you need Addism or other Data software.
To convert other file formats to the "Calculator History File" file type, you need software like Addism or a similar tool.
An .addism file is a proprietary data file created by Addism, a custom calculator application for macOS developed by Max Langer. These files are used to store the complete history of mathematical calculations, including automatically recorded steps, operations, and optional custom titles.
These files were exclusively managed by the original Addism app, which featured specialized tools to undo, redo, and review long calculation sequences on Mac computers.
Because Addism has been discontinued, accessing the data locked inside an .addism file today is incredibly frustrating. The format is entirely proprietary and closed-source. It cannot be natively opened by modern spreadsheet software like Microsoft Excel, nor is it recognized by built-in macOS calculators or Windows machines. Users who stumble upon old calculation backups often find themselves locked out of their own data without the original software.
To preserve the data, the best target formats for conversion are universally readable text files like PDF, TXT, or JSON. While the original app supported direct PDF exports, attempting to convert the raw .addism file today means you are extracting raw calculation strings, which might lose the stylized interface of the original app.
Since this format is highly specific and unsupported by standard online converters, traditional conversion attempts usually fail. If our analysis detects standard embedded structures like an Apple Property List (plist) or basic text, viewing or conversion may still be possible.
Convert.Guru analyzes your ADDISM file, detects the exact format, and lets you read the text inside.
If you want to convert ADDISM file to , you can use Addism or similar software from the "Calculation History Storage" category. In the File menu, look for Save As… or Export….
To convert files to ADDISM, try Addism or another comparable tool in the "Calculation History Storage" category.
The history of Convert.Guru began over 25 years ago in California with Tom Simondi’s file-format database. A former contributor to Space Shuttle development and a software pioneer of the 1980s, Simondi established a trusted resource for file type analysis that was even referenced by Microsoft Windows XP. Today, we use modern technology to process and convert thousands of file formats while continually improving our ADDISM converter.