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WP 31S Scientific Calculator
Note: Because the HP 30b has been discontinued, I no longer have "perfect" units available. All 31S calculators that I am shipping now have noticeable keyboard issues, where multiple keys take more force in order to register. Unfortunately there is nothing I can do about this, as this exemplifies the poor quality control of HP's current offerings.
The WP 31S is the "light" version of the 34S, which is most powerful scientific (non-graphing) calculator on the market. It is not an HP product, but it is rather a community-created product based on an existing HP calculator platform. The software of the 34S was written largely by Walter Bonin and Paul Dale, initially just as a PC program. Later, Marcus von Cube joined the team and made it run on the HP 20b/30b platform.
- HP 30b calculator, for the best keyboard
- Latest keyboard overlay pre-installed
- Latest 1.2 build of the firmware pre-flashed
- A $5 donation is given to the WP 31S team with the purchase of this product
This means I carefully attach the overlay sticker. Finally, I flash the latest version 1.2 ROM (from SVN).
Note: For international deliveries, I can ship it by First Class Mail, reducing the shipping fee to around US$25 (instead of $40+). However, there is no tracking available with this shipping method. Please email me for details.
- 149 mm by 77 mm by 16 mm (5.87" by 3.03" by 0.63")
- 113 g (4.0 oz) with batteries
- Metallic-infused transparent faceplate with black vinyl keyboard overlay, textured gray slides and glossy black back
- Hard plastic keys with traditional HP "click" feedback
- Rigid synthetic case
- Based on HP part number NW238AA (Data Sheet)
- 2 line alphanumeric display (top line with 8 dot matrix characters and 11 indicators, bottom line with 12+3 digits) with adjustable contrast
- Atmel AT91SAM7L128 ARM7 processor (30 MHz)
- 6 KB RAM, 2 KB battery-backed
- 128 KB Flash ROM
- Two CR2032 batteries, providing 9 months of typical use
- 12 digits displayed with 3-digit exponent
- Traditional RPN (Reverse Polish Notation) with four-level or eight-level stack
- Serial port header behind battery door and JTAG connector (connects to AT91SAM-ICE) inside the calculator for developers
- Externally programmable by developers via JTAG interface
Part of the HP Calculator Archive,
Copyright 1997-2019 Eric Rechlin.