There are 3 versions of NonEuclid 4.0. The only difference between each version is the Macintosh computer on which it is designed to run.
NonEuclid (oldmac) - runs on the old Macintosh with the 68000 processor.
NonEuclid (mac) - runs on a Macintosh 68020, 68030, or 68040.
NonEuclid (mac/fpu) - runs on a Macintosh with a math coprocessor.
Some macs have a switch for 32-bit mode. 32-bit mode must be OFF in order to run NonEuclid. The 32-bit mode switch is usually in the Control Panel titled "Memory".