There is a * bug with mpx+s2asm+tasm.
Lines 461,462 of mpx88.x (in the save routine for interrupts):
are converted by the posted s2asm to:
which is the same as:
Now tasm figures that since a segment override prefix is meaningless here,
what you really mean is:
which is a completely different instruction. What's more, tasm does this
quietly, without warning you. Thus, when you try to boot minix the
machine jumps to some odd location when it tries to process an interrupt.
The fix is to delete the segment override prefix. Then tasm works OK.