BS File

What are BS files and how to open them

Are you having problems opening a BS 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 BS files.

What is a BS file?

BS files have multiple uses, and Infinity Engine Compiled Character Script is one of them. Read more about the other uses further down the page.

Infinity Engine Compiled Character Script

These BS files contain the scripts that automatically guide the character's behavior based on the criteria in the environments used by Infinity Engine, a gaming engine. This file uses "triggers" and "responses". Triggers cause a response with a specific outcome, and a response is one or more calls to functions.

How to open BS files

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

While we have not verified the apps ourselves yet, our users have suggested four different BS openers which you will find listed below.

Last updated: August 25, 2026

All known file formats using extension .BS

While Infinity Engine Compiled Character Script is a popular type of BS-file, we know of 2 different uses of the .BS file extension. Different software may use files with the same extension for different types of data.

PrintFox/Pagefox Bitmap

PrintFox/Pagefox Bitmap is a raster image format used by the Printfox and Pagefox software for the Commodore 64/128 computers. Scanntronik developed both programs in the mid-1980s: Printfox was a word processor with limited desktop publishing features and Pagefox expanded on it into a full DTP system. The bitmap format called Bildschirm-graphic (screen image) stores a snapshot of what Printfox/Pagefox display in high-resolution mode, for purposes such as embedding graphics in documents or exchanging images between the programs. It is used primarily for graphics that correspond to the C64's 320×200 pixel screen view.

The format supports run-length encoding (RLE) compression, so that repeating byte runs are packed to save space. The file begins with a header byte identifying it as a Bildschirm image ($42 in hexadecimal, ASCII "B") when stored in the packed BS format. If the file is written with an explicit "0:" prefix before its name, it is stored in an uncompressed "Hi-Eddi" bitmap format instead. Pagefox can also read BS format files produced by Printfox, to support backwards compatibility.

Technically, a BS bitmap corresponds to a monochrome high-resolution image of 320 pixels width by 200 pixels height, which matches the standard Bitmap Mode on the Commodore 64. The raw bitmap data requires 8000 bytes for the pixel bits (1 bit per pixel), excluding any additional color or screen metadata the software may store elsewhere. Compressed files include an RLE pack-indicator byte ($9B) before a count of bytes: in BS (and GB) formats that count is stored as a two-byte word. The header identifier "B" (hex 0x42) appears as the first byte in packed BS files.

Various apps that use files with this extension

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

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