Die Modelle HP-75C und HP-75D waren die ersten in BASIC programmierbaren Taschenrechner von Hewlett-Packard. Der HP-75C wurde ab 1982 verkauft, 1984 folgte der HP-75D, der um eine Anschlussmöglichkeit für einen optischen Barcodeleser erweitert worden war. Die Produktion endete 1986. Eigenschaften Der HP-75 verfügt über ein einzeiliges LC-Display, 48 KiB ROM und 16 KiB RAM, ein manuell bedienten Magnetkartenleser und ein eingebautes HP-IL-Interface zur Ansteuerung von Massenspeichergeräten - hier ein KAssettengerät. Ein Texteditor war ebenso eingebaut wie Alarmfunktionen zur Erinnerung an Termine o.ä. Der vergleichsweise hohe Preis von 995 $ (HP-75D: 1095 $) stand einer weiten Verbreitung allerdings im Wege. Quelle: https://de.wikipedia.org/wiki/HP-75 HP-75C/D The HP-75C was HP\'s first portable computer. It ran BASIC, and came with 16K of RAM with an expansion port for additional RAM and 48K of ROM with 3 ROM expansion ports. It had a keyboard that was large enough to touch type on (about 95% of full size), a very readable one line alpha display and an HP-IL port that allowed it to be attached to almost anything. The HP-75 filing system allowed multiple files to be stored in ROM, RAM, magnetic cards or tape drives. All of the basic file system commands like copy and rename were included. In addition to BASIC, the HP-75 had an appointment mode with alarms and could store/edit text files. As such, the HP-75 could also be considered one of the earliest organizers. The alarms even came in 10 styles including: \"A short chirp\", \"A series of high, insistent tones\" and \"A series of eight siren sounds\". Card Reader The HP-75 used a card reader with hand pulled cards rather than the motor driven cards the earlier calculators. These cards were preformatted with clocking information to allow a pretty wide variation in \"pull speeds\". (Although mine has become rather picky in its old age.) Each card had two tracks, each track had 650 bytes. A lot of data compared to the HP-65 but rather small compared to the HP-75s memory space. Options included a CRT, small thermal and large impact printers, a modem, a plotter, a tape drive and just about anything else that could be connected to HP-IL. Quelle:http://www.hpmuseum.org/hp75.htm