Need help/advice re C compiler and portability

[Pat Kauffold]

I am looking for advice and experience with porting C programs from
a PC/DOS or MS/DOS (IBM PC or PC6300) environment to a Unix V
environment (and possibly downward to a CP/M environment?).

I want to do all development on the PC6300 and port to other machines,
primarily Unix V environments (PC7300, 3B2, PDP-11), and secondarily,
to CP/M environments.

Are there any commercially available C compilers for MS/DOS which 
require a minimum of source conversion to port to a Unix V environment?  

I would like to be able to port with no changes; I consider changes
to 5% or more code to be unacceptable.  I am not as concerned about
internal efficiency of the load modules as I am about programmer
efficiency.

Please reply to: 	Pat Kauffold
			AT&T Bell Labs
			IX 1F-373
			1200 E. Warrenville Road
			Naperville IL 60566

			ixn5f!pvk
			ixe5n!pvk