Prerequisites:

The UNIX99 runtime environment can be used in an emulation environment 
(Classic99 and MAME) and on physical hardware.

UNIX99 execution requires the following emulated or real hardware at a minimum:

• TI-99 console (i.e. TI-99/4, TI-99/4A, TI-99/22), 
  providing CPU, graphics, VRAM and sound

• 32KB or more RAM (i.e. 128k - 32M SAM RAM on a PPEB or TIPI)

• At least one persistent storage device and minimum versions:
  • TIPI - software v2.6, DSR v2025-02-02
  • WDSx
  • IDEx - DSR v17, v18 preferred
  • SCSx - DSR v1.5 or v1.6
  • Classic99 on DSK1 - (QI399.083 or better -- older QI399.072 not supported)
  • Programmable GROM hardware, (i.e. FinalGROM), 
    that provides a host for the Unix99 ROM
  • 144M or more storage on PPEB
  
Additional supported TI-99 hardware and minimum versions:
  • TI Speech synthesizer
  • PICO9918 - v1.0
  • F18A - v1.9
  • SAMS memory card
  • RS232 and Parallel I/O
  • External USB mouse (TIPI required)
  • External USB keyboard (TIPI required)