Lots of machines supported variable length operands (like the machine you reference in the link, IBM S/360, Burroughs, etc. etc. However, machines with variable length instructions not split into any kind of word boundary are not as common.
This isn't about whether a machine was good or bad / worse or better / or even level of historical interest. Just whether or not it was interesting - in particular interesting to me. If the CDC machines like that interest you, by all means have at them. ;) I note that, there isn't enough information in that manual to do what I plan to do for the IBM 1410 - reproduce the actual machine logic. Compare/contrast what you referred to to the documents at: http://bitsavers.informatik.uni-stuttgart.de/pdf/ibm/1410/drawings/ On 7/15/2015 12:10 AM, Chuck Guzis wrote: > On 07/14/2015 09:16 PM, Jay Jaeger wrote: > >> Other than clones and the like (e.g., from folks like Honeywell), I'm >> not aware of any other machines with a similar architecture to the 1401 >> and 1410. Name them? > > Well, how about a bit-addressable, variable field length machine that > had not only your basic set of floating point operations, but also > variable-length binary, binary modulo-256 and packed BCD to a length of > 65535 bytes (131K BCD digits)? Circa 1969-1971: > > http://bitsavers.informatik.uni-stuttgart.de/pdf/cdc/cyber/cyber_200/60256000_STAR-100hw_Dec75.pdf > > > When you've got a few minutes to spare, try writing the VHDL for it. > This was a Jim Thornton design, later taken over by Neil Lincoln. Later > versions of the machine had drastically reduced instruction sets from > the original, culminating finally in the liquid-nitrogen cooled ETA-10. > > But really, variable-word length machines, while they made efficient use > of storage, were pretty much limited to a character-serial > memory-to-memory 2-address organization. Quaint and perhaps > interesting, but doomed from a performance standpoint. > > --Chuck > >
