To be honest, I've forgotten many (most) of the details. But that sounds about right. As I remember it, it was like SunOS. The key point was that the kernel only had one view of the memory system period, no FS buffer cache etc...which was a departure from many of the traditional UNIX implementations. IIRC they did not support BSD's mmap -- but check the SVR3 docs to be sure -- they had the SVR3 user interfaces but none of the BSD ones. They did support the System V shared memory, however. I do seem to remember there was something funny in the driver interfaces, it was just like UNIX only different, and that causes some heartache - but it was fairly straightforward to move a DMA driver like getting a VME Xylogics tape controller to work, but it took a little tweaking. I've forgotten exactly why that was -- it's been a long time ago. Clem ᐧ On Sat, Nov 12, 2022 at 1:36 PM Larry McVoy wrote: > On Sat, Nov 12, 2022 at 01:04:30PM -0500, Clem Cole wrote: > > On Sat, Nov 12, 2022 at 11:52 AM wrote: > > > DG-UX was a pretty generic SVR3 > > > > > User space was generic. But the SVR3/88K kernel was a heavy rewrite. > > LCC did a lot of work with DG adding stuff too it -- it was very well > done > > by the DG team in NC. The memory and FS was well integrated. > > So read()/write()/mmap() all shared the same cache like SunOS? In SunOS > the > only things not in the page cache were directories and inodes. All data > pages had one, and only one, place to be (ZFS broke this in Solaris, > which has always blown my mind). > -- > --- > Larry McVoy Retired to fishing > http://www.mcvoy.com/lm/boat >