Which calculators had no known bugs?

[Mark Hardman]

From: http://www.finseth.com/hpdata/hp67a.php

[HP-67] Bugs/ROM-Versions::

There exists several specific arguments for which arcsin (and to a
lesser degree arccos) are in error:

x=0.000003000 (0.6% error)
x=0.000004000 (2.5% error)
x=0.000005000 (4.0% error)
x=0.000006000 (7.0% error)
x=0.000007000 (8.0% error)
x=0.000008000 (11.5% error, 5.11078e-4 vs 4.58366e-4!)