Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!mips!dimacs.rutgers.edu!aramis.rutgers.edu!paul.rutgers.edu!njin!spcvxb.spc.edu!havemann_l From: havemann_l@spcvxb.spc.edu Newsgroups: comp.sys.dec Subject: Re: pdp-11's Message-ID: <1991Jun24.160613.1515@spcvxb.spc.edu> Date: 24 Jun 91 16:06:12 GMT References: <1991Jun22.041102.1509@spcvxb.spc.edu> <1991Jun24.093746.48196@cc.usu.edu> Distribution: comp Organization: St. Peter's College, US Lines: 20 In article <1991Jun24.093746.48196@cc.usu.edu>, slsw2@cc.usu.edu writes: > > I spent a lot of time looking at the QBus and UNIBUS some years ago. With > block mode the QBus peaks at about 3 1/3 MB/s. UNIBUS peaks at 6 2/3 MB/s; > a memory module can support this throughput using 70 ns static RAM. > > The main problem with UNIBUS as far as modern systems go is that it has a > limited address range; 256KB as opposed to 4MB for the QBus. In the *modern* UNIBUS systems (/24/44/84/94), they have memory mapping - allowing an address range of 2048K (4 Mb's). ----------------------------------------------------------- | Lee Havemann, Sys_op HSH Associates | | Havemann_l@spcvxa.spc.edu | | "Any opinions that are expressed are my own, since this | | company can't afford to have any........" | -----------------------------------------------------------