On Sun, May 25, 2008 at 11:48 AM, Bernd Petrovitsch <bernd@xxxxxxxxx> wrote: > On Sun, 2008-05-25 at 11:26 -0400, Greg Freemyer wrote: >> On Sun, May 25, 2008 at 8:23 AM, Bernd Petrovitsch <bernd@xxxxxxxxx> wrote: >> > On Sat, 2008-05-24 at 15:39 -0400, Greg Freemyer wrote: >> > [....] >> >> I also think it is useful to realize that UNIX was basically designed >> >> for systems that have a MMU even though low-end systems in the late >> >> 70s / early 80s did not have them. >> > >> > The first ones (also before) didn't have a MMU and the first versions of >> > "Unix" ran on it. >> > >> >> I believe there were implementations that ran on 286 based hardware >> >> without MMUs way back then, but they were very kludgy and definately >> >> not the design target for UNIX. >> > >> > Of course they were as that was common hardware in the 60s and >> > (earlier?) 70s. >> >> I think you have your history a little off. (I may too.) > > Maybe. > >> Per Wikipedia: >> >> The Intel's 286[1], introduced on February 1, 1982, (originally named >> 80286, and also called iAPX 286 in the programmer's manual) was an x86 >> 16-bit microprocessor with 134,000 transistors. > > And that didn't have a MMU. MMUs came to the PC world with the 80386 Agreed, I think that is even what I said ;) >> iirc, the DEC PDP computers were some of the first computers to have >> UNIX on them. > > Yup. http://en.wikipedia.org/wiki/PDP-7 in '65. I don't think it had an > MMU. Nothing to be found around the above page about that (at least by > me). > Per http://www.catb.org/esr/writings/taoup/html/ch02s01.html >> Unix's first real job, in 1971, was to support what would now be called word processing for the Bell Labs patent department; the first Unix application was the ancestor of the nroff(1) text formatter. This project justified the purchase of a PDP-11, a much more capable minicomputer. >> So the pdp-11 was one of the very early targets for UNIX. That series did have MMUs on at least some of them. I admit I don't know exactly when UNIX started taking advantage of MMU hardware, but my first experience with UNIX was around 1981 using Perkin Elmer computers. The MMU was a well supported feature by then. UNIX for Intel x86 class machines did not yet exist. > Bernd > -- > Firmix Software GmbH http://www.firmix.at/ > mobil: +43 664 4416156 fax: +43 1 7890849-55 > Embedded Linux Development and Services > > Greg -- Greg Freemyer Litigation Triage Solutions Specialist http://www.linkedin.com/in/gregfreemyer First 99 Days Litigation White Paper - http://www.norcrossgroup.com/forms/whitepapers/99%20Days%20whitepaper.pdf The Norcross Group The Intersection of Evidence & Technology http://www.norcrossgroup.com -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
