This is a project whose aim is to recreate the Venix86 operation system source code using the Research Unix 7th Edition release as its basis. To the largest extent possible, we will endevlor to create .c sources that, when compiled with the compiler in Venix86, produce identical binaries.
For some programs, this will be easy as it's clear that the program was compiled unmodified from the v7 sources. For other programs, that will be significantly harder because the originals were written in pdp-11 assembler, or they are inherently machine dependent (like compilers and assemblers).
In addition, efforts are under way to adopt one of the 8088/8086 simulators to run Venix binaries, though it's unclear the exact scope of the project. Ideally, we'd be able to run the compilers and toolchain that way to help in the reconstruction efforts as the native machines that these run on are now quite slow (it takes about 30 minutes to build the kernel sources natively, and < 3s to build them with alternative compilers).
Venix differs from other V7 unixes in a number of ways. PC/IX, for example, does floating point emulation differently. There may be differences in object headers and such as well.