786 Part 4½ Family Range, Compatibility,
and Evolution
Section 3½ Evolution of HP Calculators
constraint on user compatibility between generations. Chapters 48, 49,
and 31 sketch the designs of the three major generations of Hewlett-Packard
desk-top calculators. Functionality has increased with each generation
and is best exemplified by the programming interface. HP 9100A programs
consisted of arithmetic keystroke functions and program control operations
(e.g., GO TO and IF). The HP 9800 series ranged from an algebraic
language through BASIC, traditionally a computer-based language. The perception
is that the HP 9810/20/30 series is matched to user functionality rather
than software compatibility. The HP 9845 also supports BASIC. This section
concludes, in Chap. 50, with some observations by Tom Osborne, one of the
architects of the Hewlett-Packard desk-top series.