I wrote:
  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. 
Tony wrote:
  Do you not consider the HP71B to be a handheld HP
calculator? 
It has a calculator mode, but I've always considered it to be a
handheld computer.  Isn't that what HP called it?