These links are taken from several sources (mainly hpmuseum.org) and our own experience

HP Calculators and Computers

• HPCalc.org - Eric Rechlin's website
• Valentin Albillo's pages on hpcalc.org
• Eric Smith's HP Calculator Page Simulators and Technical literature.
• Reverse-Engineering the HP-75C
• HP Series 80 Computers, Accessories, Peripherals and Software
• Rick Furr's Hewlett Packard Calculator Page
• HP Handheld Devices (HP Company)
• HPCC Handheld And Portable Computer Club
• HP-35 HP Journal Articles by HP
• Christoph Giesselink's website on HP calcs
• the biggest HP museum - in Australia!
• Namir Shammas monumental mathematical programs site
• HP-network in French
• The collection of Gerardo Rincon
• Engineering and HP calculators - the page of CesarV (Spanish)
• Classic Calculators - Epocalc's Site
• Kees Van Der Sanden HP calculator page

HP48/38

• HP's FTP site
• The HP48 Goodies Page by Joe Horn
• hpcalc Eric Rechlin's HP-48, 38 and 28 site.
• HP 48 GCC-based C cross-compiler
• A lot of programs in Spanish for the HP 48 in Luis Gallardo's page
• Gilberto Urroz's Calculator pages

Other Calculating and Scientific Instruments

• Old Calculators Pages by Rick Bensene
• Museum of Pocket Calculating Devices
• Disassembling a Curta Calculator by Greg A. Saville
• Planet Sinclair
• Old HP and TI Calculators by Gene Wright
• Make your own circular slide rule
• More Slide Rules
• Otis King's patent calculators by Dick Lyon
• The Analytical Engine by John Walker
• http://www.calculator.org/
• Rskey.org by Viktor Toth

Old Computers

• Paul Pierce's Computer Collection Micros to vacuum tube mainframes.
• Carl Friend's Minicomputer "Museum"
• Computer Museum Of America
• The Charles Babbage Institute Center for the History of Information Processing
• Mind Machine Web Museum
• Timeline of Microcomputers Ken Polsson
• The Digital Equipment Corporation PDP-8 by Doug Jones
• ENIAC-on-a-Chip (Someone had to do it.)
• Chronology of Events in Computer History
• Chronology of Personal Computers
• Vintage calculators - a lot of links
• oldcomputers.net

HP41c/cv/cx

• Clonix-41 official page by Diego Diaz
• Dan Pfeiffer's HP-41 page
• La page de Jean-François Garnier (auteur de Emu41)
• Emmanuel Compès
• Hewlett Packard HP-41C/CV/CX, Thimet
• HP calculator emulators for the HP calculators by HrastProgrammer
• Jean-Daniel Dodin, PPC-T
• La page HP de la maison des Calculatrices Classiques
• Le HP-41CX sur le site Voidware
• Le site dédié à la grande famille du HP 41C de Noël Jouenne
• Le site du HP-41CX
• Les calculatrices électroniques de poche par Noël Jouenne
• nonpareil HP calculators simulator for Mac OS X
• Rick Furr's HP calculator page
• Le site RPN et calculatrices HP de Pierre Hardy
• SIM41 HP-41C emulator
• The HP Collection by Matthias Wehrli
• The Museum of HP Calculators
• The X-Number World by James Redin
• Tom Boldt's RPN Calculator
• Warren Furlow's HP-41 page
• Wikipedia, HP-41

Other interesting websites

• QuitSmokingCommunity.org
• Cancer.org