SETI Hacker exercise answer     updated November 30, 2005  D. Carrigan carrigan@fnal.gov (subject line must be sensible) 

(My SETI interest is not funded by Fermilab or the U. S. Department of Energy. This portion of the site is needed to illustrate other interconnections related to Fermilab.)
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The answer

This is a subroutine to do a square root on the original Illiac I used at the Univerity of Illinois in the fifties. It  is the computer I learned on, had for my first computer course, and used to do my thesis. The later Illiac IV  is celebrated in the movie version of 2001 when HAL remembers his roots.

The Illiac hexadecimal notation was 10 (decimal) = K, 11 = S, 12 = N, 13 = J, 14 =F, 15 = L.


Extra credit hints

Prior to machine language there was hardware code at several levels like adders. Beyond machine language there is assembly language. This begat FORTRAN associated with things like JCL. For me FORTRAN was as good as it got but others wanted C, LINUX, etc. These developments were driven by the ever-quickening pace of technology (cell phones, the Web, and on and on). Look at virtual computer museums as a start.

The future is hard to predict. For perspectives see Pillars on this site.

More on the Illiac

The square root routine

The very nice Sydney University Silliac site

First five chapters of the Silliac manual (long download)

A doorway to virtual computer museums computer museums