At 11:09 PM 4/2/2017, rcs@xmission.com wrote:
In a different direction: The IBM 1620 computer (c.1962) used tables in memory for single-digit addition and multiplication. This might have been used to do arithmetic in other bases < 10.
It's been 58 years; do we have to file a FOIA request to ask NSA if they ever used the 1620 table lookup for bases other than base 10? I hacked the 1620 while still in high school, but didn't know enough math at that time to really utilize the table lookup feature for anything other than base ten. Also, I don't recall whether the machine could even boot if the arithmetic tables got wiped, so trying experiments of this form could be very dangerous. (Core memories retain their data when powered off, so wiping these tables was rare.) BTW, modern GPU's are *really good* at interpolating large tables; Google "texture mapping": https://en.wikipedia.org/wiki/Texture_mapping_unit "In GPGPU, texture maps in 1,2, or 3 dimensions may be used to store arbitrary data. By providing interpolation, the texture mapping unit provides a convenient means of approximating arbitrary functions with data tables."