Hewlett-Packard 41C Series  
Written by Accutron on 2015-05-24  

Devices included in this entry:

Hewlett-Packard 41C Calculator - S/N 1933A00680 (pictured in thumbnail)
Hewlett-Packard 41CV Calculator
Hewlett-Packard 82104A Card Reader (pictured in thumbnail)
Hewlett-Packard 82143A Peripheral Printer
Hewlett-Packard 82170A Quad Memory Module
Hewlett-Packard 82180A Extended Functions Module
Hewlett-Packard 00041-14001 Stat Pac

In 1979, Hewlett-Packard introduced the 41C calculator, effectively the world's first true handheld computer system. Unlike the earlier HP-65/67/97 programmable calculators, the HP-41C possesses an alphanumeric display, continuous memory, extensive I/O capabilities and a tremendous range of expansion options.

Unlike the HP-97 pictured above, which squeezes as much functionality as possible into a single unit, the HP-41C gains its extended functionality from various peripheral devices and expansion modules. The HP41C can use an external card reader, printer and optical wand, all of which plug into one of four universal expansion slots located in the top of the calculator. These expansion slots also accommodate RAM extensions and software ROMs, as well as a HP-IL interface module which allows the use of larger peripherals including floppy disk and magnetic tape drives.

Despite its incredible functionality, the HP-41C is plagued by a number of mechanical flaws which make it a troublesome device. The HP-41C uses a flex PCB interconnect system, which introduces potential failure points between all of the calculator's main subsystems. A single flex PCB connects the batteries, keyboard PCB and all installed extension modules or peripherals, and is highly susceptible to corrosion from battery leaks. The vast majority of HP-41C failures can be traced back to this one component. In addition to the flex PCB issue, the screw bosses in the HP-41C's case are highly prone to cracking and breaking, making any necessary servicing procedures a nerve-racking affair.

HP 41C Operating Manual (PDF)
HP 41C-CV Owner's Handbook & Programming Guide (PDF)
HP 41C-CV-CX Service Manual 00041-90472 (PDF)
HP 41C-CV-CX Memory ICs (PDF)
HP-41C-CV-CX Modules (PDF)

Hewlett-Packard 41C calculator, 1933A date code (initial hardware revision), shown with 82104A Card Reader.

Hewlett-Packard 41C calculator, expansion ports. The calculator is equipped with a 82170A Quad Memory Module and a statistical functions ROM.

Hewlett-Packard 82143A Peripheral Printer.

Hewlett-Packard 82180A Extended Functions Module. This module provides most of the extended functionality of the newer HP-41CX to 41C and 41CV calculators, including extended memory management and programmable key assignments.

Hewlett-Packard 41C calculator, three-transistor logic PCA with 'DDE' ROM configuration and four 1LA7 16-register RAM ICs. The HP-41C ROM is stored on three chips with 4K 10-bit words.

Hewlett-Packard 41C calculator, initial revision display driver. Later revisions of the display driver have circular 'blob' ICs.

Hewlett-Packard 41CV calculator, 'halfnut' hardware revision.

Hewlett-Packard 41CV calculator, 'halfnut' PCA with integrated logic and display driver.

This article is part of the [Electronic Calculators] exhibit.

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