On Sat 22 Oct 2016 at 23:03:41 +0200, Johnny Billquist wrote: > On 2016-10-22 18:55, Al Kossow wrote: > > > > > > On 10/22/16 7:44 AM, Ray Jewhurst wrote: > > > I have an idea for project to teach my self rudimentary OS design and I > > > would like to use RT-11 as an example > > > > > > > Did anyone ever port MINIX to the PDP-11? > > I don't think so. I suspect it would be non-trivial, as the memory > limitations of the PDP-11 require that you sometimes need to design with > that in mind from the start, or else face serious problems.
But the original 8086 MINIX (which I used in university in the course on operating system design) used "small memory model". That means it sets the segment registers for each process to a fixed value and therefore its processes (including kernel server processes) were limited to 64KB of text and 64KB of data. That would fit with PDP-11s with sepid just fine. At some point during inter-process communication it no doubt uses the segmentation registers more actively (I don't remember the details) but that can be done in some other ways on the -11. > Johnny -Olaf. -- ___ Olaf 'Rhialto' Seibert -- Wayland: Those who don't understand X \X/ rhialto/at/xs4all.nl -- are condemned to reinvent it. Poorly.
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