Newer IBM Thinkpads with "extended" parallel ports are not recognized by DOS unless you download and install the DOS Configuration Utility from IBM. DOS Beowulf will work fine after that.
I have been told that most newer machines have chipsets that support the IBM original "standard" mode for the parallel port, and that this mode can usually be selected in the CMOS configuration on MOST machines. Alternately, you may try setting it for PS/2.
Not really a problem, but I have discovered that optimizing the UBASIC code for one machine may slow things down if used on another. Suggest keeping the floppy with the machine you use it on. I was able to reduce the com time by 1/3 this way.