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Path: sserve!newshost.anu.edu.au!munnari.oz.au!foxhound.dsto.gov.au!fang.dsto.gov.au!yoyo.aarnet.edu.au!news.adelaide.edu.au!news.cs.su.oz.au!harbinger.cc.monash.edu.au!yeshua.marcam.com!MathWorks.Com!europa.eng.gtefsd.com!howland.reston.ans.net!EU.net!sun4nl!news.nic.surfnet.nl!tuegate.tue.nl!news.win.tue.nl!eba.eb.ele.tue.nl!eba.eb.ele.tue.nl!not-for-mail From: wjw@ebh.eb.ele.tue.nl (Willem Jan Withagen) Newsgroups: comp.os.386bsd.development Subject: Re: DMA bounce-buffers now implemented in FreeBSD-current Date: 7 Apr 1994 13:13:29 -0000 Organization: Digital Information Systems Group, Eindhoven University of Technology Lines: 38 Message-ID: <2o10tp$8oe@ebh.eb.ele.tue.nl> References: <JKH.94Mar25161128@sentnl.ilo.dec.com> <JKH.94Mar27000401@whisker.hubbard.ie> <Cnor2s.15w@aeon.in-berlin.de> NNTP-Posting-Host: ebh.eb.ele.tue.nl In article <Cnor2s.15w@aeon.in-berlin.de> thomas@aeon.in-berlin.de (Thomas Wolfram) writes: => Jordan K. Hubbard (jkh@whisker.hubbard.ie) wrote: => > In article <UWP.94Mar25194257@maelaren.cs.tu-berlin.de> uwp@cs.tu-berlin.de (Udo Wolter) writes: => => > Can anyone describe what DMA bounce buffers exactly do besides of allowing => > more than 16MB in an ISA machine ? => => > That's all they do. They also allow the usage of ISA controllers in => > EISA machines, or VLB controllers with broken DMA (like the Buslogic => > Bt445S) to work. => => Could someone please explain what "broken DMA" of Bt445S means exactly? => Does it mean it acts like a ISA busmaster DMA controller (16MB address => space only) or what? => Is there a list of VLB controllers which have working DMA? I'm usign the following combination without much trouble: DFI 486DX-2/66 256K, Opti chipset, VESA localbus 16 Mb PS/2 SIMM's Bt 445S board REV D, prom 3.36 [ I'm promissed an upgrade ASAP the new REV E boards arive Note that this is a personal favour, not a BT service. ] and FreeBSD straight from the 1.0.2 CDROM. As soon as I stick in the next 16 Mb, the system doesn't even complete te boot sequence. So I'm going to take a look at the new stuff and see what it does with this hardware. Willem Jan -- Digital Information Systems Group, Tel: +31-40-473401, Fax: +31-40-433066 Room EH 10.35 Eindhoven University of Technology P.O. 513, 5600 MB Eindhoven, The Netherlands TEAM OS/2 Internet:wjw@eb.ele.tue.nl