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Path: sserve!manuel!munnari.oz.au!spool.mu.edu!agate!soda.berkeley.edu!wjolitz From: wjolitz@soda.berkeley.edu (William F. Jolitz) Newsgroups: comp.unix.bsd Subject: Re: [386BSD] RAM > 16MB OK ? Date: 22 Sep 1992 17:36:47 GMT Organization: U.C. Berkeley, CS Undergraduate Association Lines: 21 Distribution: world Message-ID: <19nljfINNksv@agate.berkeley.edu> References: <19krluINNd2l@corax.udac.uu.se> NNTP-Posting-Host: soda.berkeley.edu In article <19krluINNd2l@corax.udac.uu.se> goran@astro.uu.se (Goran Hammarback) writes: >I know there was a discussion on SYS V UNIX for the PC, where the >conclusion was that most of these systems only handled up to 16 MB >of ram, the reason being that the ISA bus can only access the first >16 MB of memory. Does anyone know if 386BSD handles more than >16 MB ? (The obvious solution would be to use a buffer in the lower >16 MB for transfers to/from higher memory). We have a 20MB system working in-house. The idea is that you copy portions of memory on-the-fly to the "lower" physical 24-bit address. BTW, even if you have an EISA-bus machine with 32-bit address ISA compatibility, it still means you can only get to the lower 24-bits of physical address. This is why one wants to get a native mode EISA disk controller that does the full 32-bit address space, like an Adaptec 1742 or Bustek 742. 0.1 works without changes (Bill threw it in 2 hours before the tape was cut), but there is always more testing and work to do. Lynne.