I made a 9K byte program with the eval Keil tools using single file assembler source.

And a piece of info for others is that you can support multiple source files by making them all includes into a single master .A51 file that gets assembled as a "single" file.

Note that I was working with the Keil tool set that comes with the $99 Cygnal Eval kits. That version of Keil tools has some different limitations than the ones listed on the Keil web site.....although I am not quite sure I know the exact differences.

To me it is now a moot point because I got the full DK51 this weekend.
Thanks
Michael Karas