From: invalid AT erehwon DOT invalid (Graaagh the Mighty) Newsgroups: comp.os.msdos.djgpp Subject: Re: DPMI features [was Re: Peculiar behavior of program.] Organization: Low Charisma Anonymous Message-ID: <3b3c11ca.263481264@news.primus.ca> References: <3b3b4662 DOT 211401101 AT news DOT primus DOT ca> <3b3bc134 DOT sandmann AT clio DOT rice DOT edu> X-Newsreader: Forte Free Agent 1.11/32.235 Lines: 63 Date: Fri, 29 Jun 2001 05:33:14 GMT NNTP-Posting-Host: 207.176.153.3 X-Complaints-To: news AT primus DOT ca X-Trace: news2.tor.primus.ca 993792939 207.176.153.3 (Fri, 29 Jun 2001 01:35:39 EDT) NNTP-Posting-Date: Fri, 29 Jun 2001 01:35:39 EDT To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Reply-To: djgpp AT delorie DOT com On Thu, 28 Jun 2001 23:43:48, "Charles Sandmann" sat on a tribble, which squeaked: >Commercial software has shipped using DJGPP as the compiler and run-time. >If you pay for something, you expect it to work on your platform. Yeah, it was called Quake and it also shipped with CWSDPMI. >No software exactly implemented either standard exactly that I know of. And the world ... yup. Still spinning, judging by the continued creep of stars across the sky out my window. >0.9 was so weak that no implementation only provided the 0.9 features. >The 1.0 version was so complicated and rich that noone bothered. Since >I avoid threads completely without certain key words in the subject, I'm >not sure what "feature" is being discussed - but I'll guess null page >protection. If you don't want this feature you can use CWSPARAM on r5 >to set flag "4" and be happily ignorant of programming errors. You're joking, right? That's not a feature, it's the absence of a bug. Any host that doesn't trap errors like those has a bug, rather than lacks a feature, IMHO. Actually, what was under discussion was its use in auto-detecting the host vendor and version. >A signature was added to r5 of CWSDPMI (0x401 - a DPMI 1.0 function) at >Eli's request. However r4 did not support this, and there are hundreds >of thousands of copies of CWSDPMI r4 and earlier out there. And anyone who needs the ident code can get this feature for the all-time low price of ... $0.00! >But if anyone really needs CWSDPMI ident code, the page table locating >code is very specific to CWSDPMI, and works since early betas. However, >this is a very bad thing to do unless you know exactly why you are doing >it... It wasn't for end programmers to mess with; I was considering the idea of a CWSDPMI with some extra features to add debugging abilities, and DJGPP startup code changes to detect and activate/support those features, after it got mentioned that DPMI proper is rather limited when it comes to debugging support. >Sigh. It is, by the way. Other people have written their own 32-bit >environments on top of it, and even embedded it into ROM. Hm. First rule of open source: it will wind up in someone's kitchen sink? >CWSDPMI is small, tight, specialized code implementing a standard. >While there are some features which help to support DJGPP, I have no >plans to put anything environment specific into the DPMI provider. Hmm. Suggests making a CWSDEBUG separate copy then. After all the production system you ship doesn't need debugging features anyways. We hope. -- Bill Gates: "No computer will ever need more than 640K of RAM." -- 1980 "There's nobody getting rich writing software that I know of." -- 1980 "This antitrust thing will blow over." -- 1998 Combine neo, an underscore, and one thousand sixty-one to make my hotmail addy.