Path: csiph.com!x330-a1.tempe.blueboxinc.net!newsfeed.hal-mli.net!feeder3.hal-mli.net!newsfeed.hal-mli.net!feeder1.hal-mli.net!eternal-september.org!feeder.eternal-september.org!mx04.eternal-september.org!.POSTED!not-for-mail From: Anne & Lynn Wheeler Newsgroups: comp.arch Subject: Re: M68k add to memory is not a mistake any more Date: Wed, 01 Feb 2012 14:50:18 -0500 Organization: Wheeler&Wheeler Lines: 25 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Injection-Info: mx04.eternal-september.org; posting-host="flB8D8UDsSa5S1dRygySQg"; logging-data="5831"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+5JvPKsSaYEE6bSd3D/flfWz9POeA/07k=" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.3 (gnu/linux) Cancel-Lock: sha1:SYhF0MvdCvbYkBzVhv97HHfdnuM= sha1:GvMwt9OINfNA67oyXWQDbgpVDTg= Xref: x330-a1.tempe.blueboxinc.net comp.arch:5653 ChrisQ writes: > Fwir, there was a 360 on a couple of 68k devices using different microcode, > built by ibm, but you might be disappointed in the performance, even if you > could find one now. it was problem mode 370 ... a couple boards in pc ... initially released for pc/xt as xt/370 ... ran a modified version of vm370/cms ... initially with 384kbyte 370 memory ... and about 80kips (about the MIP rate of 370/115). an issue was all i/o was via communication with cp/88 running on the pc processor ... and disk activity was read/write record on the xt 100ms/access hard disk. I do some performance work and show that after vm370 fixed storage requirements ... most CMS applications tended to page-thrash in the remaining pageable memory. I then get blamed for six month schedule slip in announce&ship while they upgrade the boards to 512kbyte 370 memory. the additional 370 memory mitigates the page thrashing ... but cms applications tended to be quite a bit more disk intensive than equivalent PC applications ... which tended to be quite noticeable with the XT 100ms/access disk (having come over from mainframe disk environment where there was less of a disk activity bottleneck). -- virtualization experience starting Jan1968, online at home since Mar1970