On Sun, 2008-05-25 at 12:46 -0400, Greg Freemyer wrote: > 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 Yes, running version 7 according to http://en.wikipedia.org/wiki/PDP-11, years after the PDP-7. > 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. Yup. > UNIX for Intel x86 class machines did not yet exist. ACK Bernd -- Firmix Software GmbH http://www.firmix.at/ mobil: +43 664 4416156 fax: +43 1 7890849-55 Embedded Linux Development and Services -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
