Thanks Ron, and all others. Theres plenty of grist for the mill, time for me to grind it. Paul *Paul Riley* Mo: +86 186 8227 8332 Email: paul@rileyriot.com On Tue, 2 Jun 2020 at 07:59, Ronald Natalie wrote: > As far as the early UNIXs go, any disk is collection of 512-byte blocks. > The filesystems either the early (what I’ll call V6) and the later (V7) > don’t differ much. > The primary difference is that the later V7 had 16-bit uids and a > provision for larger file systems/sizes. The V6 file system was limited > to 2^24 blocks while V7 > did 2^32. > > The 512 block size corresponded to the native sector size of all the DEC > hardware except the RX which I think only had 128-byte sectors. But > again, we didn’t > do much with that other than write the standalone console disks for the > 780 (in RT format) and I also used it to make “unix” file system disks for > the BRL “LOS” > (little operating system…no time for sharing, uniprocessor system) that > ran our internet routers and the IO hardware on the HEP supercomputer. > > >