Download Current Versions
C64 Assemblers
Turbo Macro Pro Sep'06
(+REU, X2, +DTV/PTV)
Cross Assemblers
TMPx v1.1.0
(Win/OSX/Linux/FreeBSD/Solaris)
Source Conversion
TMPview v1.3.1
(Win/OSX/Linux/FreeBSD/Solaris)
There should be no issues with porting source that assembled using Turbo Macro Pro on the c64 platform to a platform on which TMPx is available. The key issue is the difference between PETSCII and ASCII and the inability to represent many PETSCII characters in a plain ASCII document. TMPview is a separate tool that assists in porting source by converting binary source files saved from Turbo Macro Pro (or practically any Turbo Assembler variant) to an ASCII representation that can be assembled by TMPx. See docs for TMPview here.
With some planning, you can code for TMPx but still provide for the ability to port the code back to the c64 for use in Turbo Macro Pro. Some things to be aware of: