TSX-32
TSX-32 has been a general purpose 32-bit multi-user multitasking operating system for x86 architecture platform, with a command line user interface. It is compatible with some 16-bit DOS applications and supports file systems FAT16 and FAT32. It was developed by S&H Computer Systems, and has been available since 1989.
DEC-oriented columnist Kevin G. Barkes noted that TSX-32 is "not a port of the PDP-11 TSX-Plus" and that it runs well on 386, 486 and Pentium-based systems.[1] He reported a limitation: since it supports the MS/DOS (FAT) file system, filenames are DOS's 8+3.