Coconut The Coconut series


The Coconut series is the first series of calculators from Hewlett Packard that uses a LCD display. This type of display consumes less power compared to the LED display and makes it possible to design dedicated displays that can also display characters and annunciators. This series was also the first series that uses CMOS chips i.s.o. the PMOS chips.
These improvements resulted in a much lower current consumption.

The calculators from the Coconut series have four expansion slots. A whole range of modules are available to extend the memory of the calculator or to control an HPIL link or a printer. This calculator was a big success. The HP-41CX model has been build for more than 11 years.

There are two versions of this calculator models. The early models have all control logic (except the LCD drivers) on a separated printed circuit board. This board is connected by a connector to the main circuit board, that contains the keyboard switches. This version with the second circuit board is known as the fullnut version. From 1985 on, the logic circuitry was further integrated and placed on the main circuit board. This version is known as the halfnut version.

A difference on the housing is the bezel around the LCD display. For the fullnut version the corners are squared and for the halfnut version the corners are rounded. See also the pictures below.

Model Code Type Short description
HP-41C Coconut Scientific Basic calculator
HP-41CV Silverbird Scientific A HP-41C with V (5) times the amount of memory of the HP-41C.
HP-41CX Honeynut Scientific A HP-41CV with timer and additional functionality.


The display

The calculators have a twelve digit seventeen segment alphanumeric LCD display. Above and below these 12 digits are additional symbols (annunciators).

Display HP41 Readout in normal mode
Display HP41 Readout in ALPHA mode, used for entering of label names.
Display HP41 Display of a fullnut version. The bezel around the LCD display is squared.
Display HP41 Display of a halfnut version. The bezel around the LCD display has rounded corners.


The keyboard

Toetsenbord HP41

The keyboard counts 35 keys.

Just below the display are four additional keys.

Each key can be reprogrammed by the user. This opens the possibility to use each key as a dedicated function key. Additional keyboard overlays are available to relabel the keyboard. For of the shelf programs these keyboard overlays were included with the software package. For homemade programs blank keyboard overlays are available with stickers.



Code   Description
HP 82104A Magnetic Card Reader
HP 82106A Memory module adding 64 registers
HP 82111A Vinyl case
HP 82120A Rechargeable battery pack
HP 82143A Thermal printer
HP 82151A Module holder
HP 82152A Keyboard overlay kit
HP 82153A Wand bar code reader
HP 82160A
HP-IL Interface module
HP 82161A
Digital Cassette drive with HP-IL interface
HP 82162A
Thermal printer with HP-IL interface
HP 82163A
Video interface with HP-IL interface
HP 82170A Memory module adding 256 registers
HP 82180A Extended Functions module adding 127 registers
HP 82181A
Extended Functions module adding 239 registers
HP 82182A
Module with clock and time functions
HP 82183A
External I/O Module
HP 82184A
Plotter module
HP 82200A
Flexible keyboard overlay (Touchpad)
HP 82242A Infrared interface (Interface to control an Infrared printer)
Dia show


Internal view

The HP-41CV fullnut opened : An HP-41CV fullnut opened.
The HP-41CV halfnut opened: An HP-41CV halfnut opened.


HP41 related links: