Texas Instruments TI-89 Tip List page 393

©Speed units
_ft/_s→_fps
_m/_s→_mps
©Acceleration units
_ft/_s^2→_fps2
_m/_s^2→_mps2
©Density units (not in built-in menu)
_kg/_m^3→_kgm3
_lb/_ft^3→_lbft3
EndPrgm
Just run units() to define all the units it includes. Note that the density units will not be put in the built-in
menus, since there is no Density category. These units can be used by typing them in the command
line, or by putting them in a custom menu.
Note that your custom units cannot be archived. The 89/92+ considers them to be system variables,
and prevents the archive.
(Credit to Mike Grass)
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