TS-UGOS E2 (codenamed Sidorak) is a graphical operating system developed and released by Theorysonic. It includes fixes for many minor issues that came with TS-UGOS E1. It was released on January 16, 1986. A year after its introduction, TS-UGOS E2 was succeeded by TS-UGOS 2.
- Fixes of many bugs and issues, including a bug that would crash the operating system if left running for 24.8 days
- Acura Stereo support
- Improved performance
- Theorynet is now preinstalled on the operating system
- Improved storage