Up for sale is a brilliant HP 48GX graphing calculator. Unlike the vast majority of vintage calculators listed on marketplaces that are sold completely "untested" or "turns on only," this specific unit has been meticulously run through rigorous, comprehensive hardware benchmarking routines to guarantee complete functionality.

Diagnostic Testing & Performance Summary:

• Keypad Matrix (KBD1): 100% Passed. Every single physical key, button, and command registers smoothly on the first press. The unit cleanly cleared the thorough KBD1 diagnostic sequence with zero dead or sticky buttons.

• Internal Logics (OK 48): 100% Passed. The central processing unit (CPU), logic board, internal ROM, and baseline 128KB RAM banks all cycle perfectly and boot to an absolute pass status.

• Card Expansion Slots: Fully tested and operational. The calculator instantly reads, maps, and partitions expansion cards inserted into both Slot 1 and Slot 2.

• Infrared (IR) Beam Transmitter: Fully verified. Optically tested and confirmed to cleanly output calculations to the vintage HP 82240 printer series.

Cosmetic & Screen Condition:

The calculator is in fantastic physical condition with clean text labels and secure rubber feet. The liquid crystal display (LCD) is high-contrast, crisp, and completely readable.

Pocket Guide: This pocket guide is confirmed as the First Printing from April 1996, which was the very first commercial run published by Grapevine Publications. You can verify this on its inner copyright page, which explicitly states "First Printing — April 1996" alongside its original matching ISBN 0-931011-45-0, predating the later 1998 revised editions.

Please examine pictures for manual and pocket guide condition.

What's Included:

* HP 48GX calculator

* Pocket Guide

* Paper Tech calculus derivatives card

* HP 48G Series Users Guide

* HP zipper case