In the process of digging through Big Blue Disk magazine's content, I found that all its images were stored in a strange .pak format. In short, the first byte is a 3D9 port value, followed by a two-byte RLE (Run-Length Encoding) marker. All the content is then packed using these markers.
I decided to create a packer and unpacker for this format. You can test the result in three ways:

• Web browser https://shadwork.github.io/C90-BigBlueDisk-Paktool/
• Diskette image https://github.com/shadwork/C90-BigBlueDisk-P … releases/latest
• Docker container https://github.com/shadwork/C90-BigBlueDisk-P … luedisk-paktool

The browser version can work offline if you download the web page, disk image has been tested on real hardware with a CGA video card, Docker image uses DOSBox and requires additional X configuration on Windows. Test images are available in the disk image and in the GitHub repository folder: https://github.com/shadwork/C90-BigBlueDisk-P … e/main/examples
All CGA art was generated by AI. Link to source code https://github.com/shadwork/C90-BigBlueDisk-Paktool. For cgaview and pakview Turbo C project file is included. In process of development i also created some CGA video wrapper implementation for Windows - AI generated, its work fine but MacOS and Linux not production ready.