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Hewlett Packard HP-41CX

• Type: Programmable RPN Electronic Calculator
• Size: 3 x 5.5 inches / 8 x 14 cm
• Serial number: 2344S41625
• Date of Manufacture: October 1983

Accessories (photo at right):

• Hewlett Packard 82104A Magnetic Card Reader/Writer (atop calculator)
• Hewlett Packard 82143A Thermal Printer Plotter (not pictured)
• Hewlett Packard 82153A Optical Wand (lower right)
• Hewlett Packard 82160A HP-IL Module (beneath card reader)
• Hewlett Packard 82161A HP-IL Digital Cassette Drive (left)
• Hewlett Packard 82162A HP-IL Thermal Printer Plotter (right)

Modules

Expansion modules

Stat Pac Thermal and Transport Science Pac Machine Design Pac Math Pac Structural Analysis Pac Hewlett Packard 82183A Extended I/O

With faux leather soft case, manuals, several expansion ROMs and other accessories, listed below.

This is the calculator that dominated the 80's. In high school I was oscillating between a 41C and the Texas Instruments TI Programmable 59. The 41C cost $115 more than the 59, and the 59 included a math expansion module (another $100 for the 41C). Also, a buddy could get me a 59 at wholesale. At $180 the choice was clear. But it was a compromise choice.

The 41s were so powerful that they couldn't fit all the functions on the keyboard. So they added an alphabetic capability so you could access the functions they couldn't fit, and a programmable key feature for when you go tired of typing the same word over and over. The manuals insisted on calling the unit a "computer". With the wide array of peripherals available, they were right.

Most users also sprung for the card reader/writer (again standard in the TI-59). I think this was because the only softcase available for the calculator was too long. On purpose. Of course, they stuck a bit of foam in the bottom, so if you hadn't gotten your card reader yet, you didn't have to dig around. But imagine the embarrassment at having to shim up a three hundred dollar calculator!

HP-41CX, with card reader and soft case

Reverse, with optical wand

Look at this poor fellow: he looks like he's been muzzled! This is the protective keyboard cover favored by surveyors and other outdoor scientists. It doesn't make the unit completely waterproof, but it helps to keep the rain out of the keys.