make -fto_lib.mak make -fmaketest.mak
to make the library and test files. These will produce files that use floating point emulation, and default Borland optimizations. The library will not include debug information and the test files will include it. I had some trouble creating the libraries using the speed optimizations. The test files produce garbage even though they link without errors. The optimizations work well from the IDE though.
I also had some trouble with BCC v3.1 when trying to link to the library. I would get error messages about the contents of the lib file after it had been created. Apparently the way BCC v3.1 releases its DPMI memory corrupts the memory on my machine so the link step fails. I could reboot and the problem vanished. This problem also occured when I tried to use the makefile for some of the Borland object libraries. I had to reboot before each link. Make sure to run chkdsk if this occurs.
This problem resolved when I started using the most recent version of emm386.sys and himem.sys, which shipped with Windows 3.1.