🚀 go-pugleaf

How do you make dos interrupt calls that expect as one of it's input
parameters a 32 bit pointer?

I'm trying to make dos 0x10 interrupt call function 0x1072 (to read
and write colors to the color registers on the vga card).

I'm using watcom 9.0, dos 5.0, and 32bit dos4gw dos extender.
I've read the "commonly asked questions" and the library ref for watcom
thoroughly, but was unable to figure out how to solve my problem.
I need to do dos interrupt 0x10. I've successfully used dos
interrupt calls with int386() and int386x(), but now I am
making a call that passes a 32 bit pointer through the dx register
as an input parameter. 

One of the manuals implied that if I simply filled in edx with my
32 bit pointer, it would take care of segment and offset translation
for the int0x10 call. Well, I tried it and it does not work. I even
tried _FP_OFF() and _FP_SEG() with int386x() and splitting it into
two pointers myself and that doesn't work.

- Frank