Tony wrote:
  One of my related interests is programmable
calculators (which are
 really  computers IMHO -- or at least I've love to see a sane
 definition which  excludes them). I've been using an HP65 (100 program
 steps, 10 registers  (variables)), an HP67 (224 progam steps, 26
 variables), and so on. 
 Dwight wrote:
  Oh no!
  Tony has brought 4 bit computers into the world of being
 useful. 
 Actually, all HP handheld calculators made before 1986 used
 56-bit words, and 10-bit instructions.  The HP-01 watch was similar
 but used a 48-bit word.
  We are just lucky that one can't make a
useful 0 bit computer. 
 Does an analog computer count as being a 0-bit computer, since it
 doesn't have any bits?  :-)
 Were there any interesting 1-bit computers other than the Motorola
 MC14500B Industrial Control Unit?