The Zenith Programmer's Utility Pack for MS-DOS contains source code and
compiler utilities needed for building an MS-DOS BIOS (IO.SYS file)
for use with the Zenith Z-100 (not IBM hardware compatible), the
Zenith Z-100 PC (IBM hardware compatible), and the Zenith Z-100 PC
running in Z-100 compatibility mode.
applicable hardware platforms, and the compiler utilities.