dos and intr

Hi, I use the Pascal gnu on a PC-i386 machine (with rhide), with gpc-19990430-i386-pc-djgppv202 (i have the same problem with the version 19990813 or 19991030). I want to use the function intr, but in the dos unit, there is only a comment about it and i didn't find the definition. For now, i use my own intr with a asmname ?__dpmi_int', but i want to know if there is a unit how do this. Second question: how can i access directly to the screen (address a0000)? Thanks. Opie