CJR File

What are CJR files and how to open them

Are you having problems opening a CJR 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 CJR files.

What is a CJR file?

A .CJR file is a Panasonic JR Cassette Image file.

Panasonic JR Cassette Image files store software or data originally saved to cassette tape from the Panasonic JR-200/TR-200U home computer. They capture the digital data blocks as they were encoded for tape so the contents can be loaded through emulation or converted for playback through the computer's cassette interface.

Such files are produced by emulators or tools working with JR-200 tape formats. They represent the saved program (BASIC or binary) in its original block-based structure, preserving file name, data blocks, lengths, checksums, and addresses exactly as they were written for tape. Emulators like VJR-200 mount these files as virtual cassette media so that the JR-200's LOAD or MLOAD commands behave as though reading from an actual cassette. Other programs convert between this cassette image format and audio WAV files for loading via the machine's cassette port.

The internal structure consists of multiple blocks. An initial "Identifier" block includes a fixed pattern (2, 42), a block number (0), and a fixed length field (26 bytes), followed by metadata like filename. Subsequent "Data blocks" follow the same starting values and include payload bytes. Each block ends with an 8-bit checksum summing all prior bytes in that block, including the starting values. The final block includes a "Tail" section.

The file format can be recognized by its signature: bytes 0x02 followed by 0x2A at the start of each block, especially at offset zero in the Identifier block.

How to open CJR files

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

We have not yet verified any programs for Windows that work with this specific file format. If you know one, please use the 'Suggest a program' link below. Thanks!

Last updated: August 31, 2026

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