from
The Free On-line Dictionary of Computing (8 July 2008)
IBM 709
<computer> A computer made by {IBM} oriented toward
scientific work. The 709 had the same basic architecture as
the {IBM 704} but with many {I/O} and performance refinements
over the 704.
The IBM 709 (like the 704) had 36-bit memory words, 15-bit
addresses and instructions with one address. A few {index
register} instructions had the infamous 15-bit decrement field
in addition to the 15-bit address.
The {IBM 7090} was a transistorised version of the 709.
[Difference between 704 and 709?]
(1999-01-19)