Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!pacific.mps.ohio-state.edu!linac!att!rutgers!cmcl2!uupsi!fozzie!stanley From: stanley@phoenix.com (John Stanley) Newsgroups: comp.sys.ibm.pc.misc Subject: Re: Direct address access via C Message-ID: Date: 29 Jan 91 02:34:20 GMT References: <1991Jan28.202900.11946@unhd.unh.edu> Organization: Not BIFF At All (NBAA) Lines: 27 rg@msel.unh.edu (Roger Gonzalez) writes: > I'd like to directly manipulate the text video area via Turbo C. I gather > that it is located at B something or 8 something, depending on your adaptor. > How do you do the memory access, though? On a VMEbus based machine, all > you have to do is coerce a pointer to be the address, and then you can do > stuff like overlay structures on the memory map. Well, for TurboC, all you need to do is coerce a pointer to be the address, and then you can do stuff like overlay structures on the memory map. Look in the manual under MK_FP. You will need to be in at least large model (I think) to do this. > Is there any speed gain in doing C->addr manipulations rather than using > Turbo's (a little too restrictive) routines, or do I have to learn Intel's > assembler to really get anything out of it? You should be able to increase the speed a little. As always, if you want top speed, and can afford to invest the time, use assembler. > "The question of whether a computer can think is no more interesting > than the question of whether a submarine can swim" - Edsgar W. Dijkstra But even more interesting, can computers swim and submarines think? Yeth, thomtimeth they DO think.