Re: How many variations of Dos 3.3 RWTS are there?

[Antoine Vignau <antoine.vignau@laposte.net>]

If the code is well written, the RWTS is called through a jump to $3D9 with IOB table pointer in A and Y.

If not, as you wrote, that will be difficult to handle because some may have rewritten the RWTS completely (for instance, in Ultima IV, A and Y registers for the IOB table pointer were swapped)

What you can try is replace the weird RWTS with a standard one and see if the program loads,
Antoine