Xref: news2.mv.net comp.os.msdos.djgpp:614 From: Charles Sandmann Newsgroups: comp.os.msdos.djgpp Subject: Re: Issues with nearptr's. Date: Fri, 26 Jan 1996 18:16:15 CST Organization: Rice University, Houston, Texas Lines: 16 Message-ID: <31096ecf.sandmann@clio.rice.edu> References: Reply-To: sandmann AT clio DOT rice DOT edu NNTP-Posting-Host: clio.rice.edu To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp > I'd like to use nearptr's to access physical memory currently occupied > by video hardware. SOunds pretty simple, no? Well, I've read rumours > that there are dangers involved in setting the NEARPTR flag in my crt0 flags. The only known dangers are that a stray pointer can destroy the interrupt table, DOS, driver data, Windows, or anything else in memory. If you always program without bugs, you have nothing to worry about :-) > One problem I have noticed is that when running under gdb, gdb > crashes when I use this flag and try to print out large data structures. > Are there any other possible issues? What's really going on in there? This really shouldn't be related, and I don't know why this would make a difference. With nearptrs you could overwrite GDB's memory, but this might actually be seen with the default non-move sbrk anyway, since the debugger and program could end up with their memory laid out ABABAB.