From: Brian Luczkiewicz Newsgroups: comp.os.msdos.djgpp Subject: Re: **MAKING OS** Date: Tue, 20 Jul 1999 13:46:18 -0400 Organization: University at Buffalo Lines: 33 Message-ID: <7n2cia$jjr$1@prometheus.acsu.buffalo.edu> References: <7mt7ta$52f$1 AT ionews DOT ionet DOT net> NNTP-Posting-Host: ubppp233-150.dialin.buffalo.edu X-Newsreader: Microsoft Outlook Express 4.72.2106.4 X-MimeOLE: Produced By Microsoft MimeOLE V4.72.2106.4 To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Reply-To: djgpp AT delorie DOT com I have made afew attempts at this myself (with little, but some luck). I don't think it would be impossible for it to run under dos, but for it to stand alone, you usually need to set up interrupts (anything above 0x20 is ok). This is difficult (if not impossible) in c++, so I would recommend assembler for at least the IDT and the GDT. DJGPP should be good, but you won't be doin' very much printf-ing until you rewrite the standard library to use bios functions. There are also a few things you should set down for yourself ahead of time: Protected mode or not? (DOS is not. DOS runs in real mode) Multitasking or not? Real Time or not? Multithreaded or not? Networkable or not? The list can go on. Try to find the linux kernel sources for v0.01 (kernel.org has 'em in the historic directory). They make for good reading, even though they have a tendency to be a little bit hacked over in some places. (Such as the interrupt handler that does one thing, print to the screen "Undefined Interrupt"). -Zorr IOnet News wrote in message <7mt7ta$52f$1 AT ionews DOT ionet DOT net>... >I am trying to write my own o/s in c++, i really dont know where to start. >I am an advanced c++ programmer but never tried an OS. any help would be >great. I want it to run under dos maybe, but not for sure. It would be >good if it could run all on its own > >