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Hewlett-Packard HP 28S (Clamshell? ORLANDO)

Hewlett-Packard HP 28S

The Hewlett-Packard HP 28S is a graphing calculator with 10 digits precision and RPN (reverse polish notation) logic. It has 1500 functions, 78 keys, and an LCD (liquid crystal) display.

Facts at a glance:

FeatureValue
TypeGraphing
Functions1500
Keys78
Precision10
LogicRPN
Display typeLCD
Display size137
PrinterIR ext
Length165mm
Width191mm
Thickness13mm
Weight227g
Year introduced1988
Year discontinued1992

Diagnostics

Note that diagnostic tests generally delete any data on the calculator. Be sure to back up any important information held in the calculator before running these tests.

Hold down ON button and press fourth key on top row of right-hand keypad, then choose test from menu (use EXIT to leave test and go back to menu). Use ON and fifth key on top row to run a test sequence. Use ON key and third key on top row to reset calculator after tests.

Replacements:

If you have a Hewlett-Packard HP 28S that is no longer working, you can consider replacing the calculator with a modern equivalent. We suggest the following current model as a replacement:

See other calculators by Hewlett-Packard