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Newsgroups: comp.os.386bsd.development Path: sserve!newshost.anu.edu.au!munnari.oz.au!news.Hawaii.Edu!ames!agate!howland.reston.ans.net!darwin.sura.net!news-feed-2.peachnet.edu!umn.edu!csus.edu!netcom.com!hasty From: hasty@netcom.com (Amancio Hasty Jr) Subject: Re: V86 mode & the BIOS (was Need advice: Which OS to port to?) Message-ID: <hastyCBLx1M.9BC@netcom.com> Organization: Netcom Online Communications Services (408-241-9760 login: guest) References: <108137@hydra.gatech.EDU> <1993Aug10.195941.17468@fcom.cc.utah.edu> <108354@hydra.gatech.EDU> Date: Wed, 11 Aug 1993 18:08:10 GMT Lines: 62 In article <108354@hydra.gatech.EDU> gt8134b@prism.gatech.EDU (Howlin' Bob) writes: >In <1993Aug10.195941.17468@fcom.cc.utah.edu> terry@cs.weber.edu (A Wizard of Earth C) writes: > >>In article <108137@hydra.gatech.EDU> gt8134b@prism.gatech.EDU (Howlin' Bob) writes: > >Dosemu also allows the use of I/O addresses > 0x3ff in a different way; >I/O instructions to those addresses trap into dosemu. dosemu sets IOPL >to 3, does the I/O, puts the result into the appropriate register, >resets IOPL to 0, and returns. As most of the useful registers lie >below 0x3ff, this really isn't as bad as it sounds. As for Windows >and Autocad using high registers, I would imagine it depended more on >the video card in use than on the application. Great idea! > >>*must* be able to put the video into a *known* state -- and the only way >>it can do this is *from* a known state. Here are several instances where XFree86 and XS3 can restore the vga to a known state. The logic and code to accomplish this is simple so we can put it in the kernel or a separate program (much easier to maintain and upgrade). It is not a difficult task -- I have a simple dos program to test S3 cards which restores the state of the vga card. > >I do agree that a kernel with knowledge of video modes would be preferable. >However, the effort to write video drivers for all the cards and >mode extensions, and ramdac sizes, and programmable clocks, etc. >would parallel the total effort put into the free Unices so far. I think that most people objecting to dosemu are the ones not dealing with the vga vendors, chip manufacturers etc. And, it is a royal pain to deal vendors... Right now, I would consider a great or gigantic step for 386bsd to have a minimal dosemu. Folks, dealing with all these different vga cards is not getting easier but harder. I just barely got my S3 928 card initialized at 1280x1024 using my dos test program and it was hard. I feel stupid doing all the bit register manipulation when all I had to do was a simple bios call to initialize the stupid card. Perhaps, the first 386bsd dosemu will not be perfect but by far it will beat what we have today. Hope this helps, Amancio Hasty -- This message brought to you by the letters X and S and the number 3 Amancio Hasty | Home: (415) 495-3046 | ftp-site depository of all my work: e-mail hasty@netcom.com | sunvis.rtpnc.epa.gov:/pub/386bsd/incoming