s/couple of people/couple of families/ ᐧ On Thu, Jan 25, 2018 at 8:47 PM, Clem Cole <[email protected]> wrote:
> > > On Thu, Jan 25, 2018 at 7:46 PM, Johnny Billquist <[email protected]> wrote: > >> >> Domain OS using 1056 bytes? On what systems? I used a lot of DN3000, 4000 >> and 5000 systems, and they used bog standard disk drives with 512 byte >> sectors. (Interesting systems in some ways, but their windowing system was >> pretty horrible.) > > > All of the early ones -- until the DN10000 I'm pretty sure. They used a > 1024 basic block, but Mike Spourer had used the Xerox Alto trick of putting > some of the FS metadata into the controller microcode. That's what the > extra 32 bytes were. Masscomp and Apollo used the same SMS 'OMPTI 7000' > controller for the ST506/ESDI drives, and you'll see it in the > SMS marketing literature as it says something like "Supports 512/1024/1056 > block sizes". I have controller doc somewhere in my basement - thinking > about it, SMS might have even supported blocks as large as 4K - but I > definitely remember them putting the 1056 stuff in for Apollo. Remember > we all knew each other, the firms were one town apart and couple of people > had somebody working at each. > > Anyway, with the DN10000, Apollo started to use the Xylogics 4xx > controllers and Xylogics either wanted too much money for custom microcode > or the Apollo guys decided custom microcode was too expensive. In our > Stellar days, we used to kid Mike about the 1056 bytes choice. BTW, Mike > might have done the same thing at Prime, I never looked at/knew much the > low level I/O of those systems. [@Stellar we used 4096 as the basic size > but that was a multiple of 512 so it was never an issue]. > > I've lost track of Mike, but Scott Baden (who is now a Prof at UCSD) was a > CPU guy on Prime 750 and I'm still pretty close too, and he might know. > I'll ask him if he remembers next time I see him. > > Clem > ᐧ >
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