Hi Having written code for a 4K PDP-8, I suspect that more of the heavy lifting was hand optimized assembler rather than Fortran. More or less, compile it / it doesn't fit / poke into it / fix it / recompile it / poke it some more / give up & hand optimize the problem areas.
Bob On Dec 29, 2012, at 10:32 PM, Magnus Danielson <[email protected]> wrote: > On 30/12/12 02:46, [email protected] wrote: >> Also about ensembles, >> >> http://www.mksa.deit.univpm.it/biblioteca/sala_tecnica/scaffale_strumenti >> /Campioni/EPSG070861.pdf >> >> This article describes combining 4 HP 5071A standards. >> >> Description on page 2 and block diagram in figure 2. >> >> Unfortunately no details on the controller are given! >> >> It's what I'd like to do to two or more HP 5065A >> >> Anyone know what they did in the controller? > > I'd assume that this is similar to what is described in Chapter 9 of NBS > Monograph 140, by Dr. David Allan and friends: > > http://tf.boulder.nist.gov/general/pdf/194.pdf > > When reading the FORTRAN code, one has to realize that the ER calculations is > hard-wired to the way that the NBS setup at the time where done, so that the > 8 clocks was compared by a number of pair-wise measures and that the > time-differences is combined as needed where some of the clocks becomes > transfer standards in the comparison back to the primary reference standard. > Clock 3 is the main clock in the hookup. > > A modern view on things is found here: > http://tf.boulder.nist.gov/general/pdf/816.pdf > > The original time-scale algorithm ran on a PDP-8 machine with 4k word memory, > coded in Fortran by Dr. Allan. Today they run using a pair of redundant 386 > machines and using a blend of Jim Greys buffer and mixers and that of > commercial time-interval measurement rig. > > Cheers, > Magnus > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
