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website/content/museum/hewlett-packard-hp-75c-75d.md
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---
title: Hewlett Packard HP-75C / 75D
categories:
- Computers
types:
- Pocket
origins:
- U.S.A.
years:
- '1982'
cpus:
- 8 bits
params:
name: HP-75C / 75D
image: /media/museum/photos/hp_75c_system_1.jpg
company: /companies/hewlett-packard
company_name: Hewlett Packard
specs:
- label: NAME
value: HP-75C / 75D
- label: MANUFACTURER
value: Hewlett Packard
- label: TYPE
value: Pocket
- label: ORIGIN
value: U.S.A.
- label: YEAR
value: |-
75C : September 1982\
75D: 1984
- label: END OF PRODUCTION
value: |-
75C : May 1984\
75D : 1986
- label: BUILT IN LANGUAGE
value: Basic interpreter, Visicalc spreadsheet
- label: KEYBOARD
value: 64 keys. Each key is user-definable
- label: CPU
value: 8 bits, called Capricorn
- label: RAM
value: 16 KB
- label: ROM
value: 48 KB
- label: TEXT MODES
value: LCD display. 1 line x 32 chars.
- label: GRAPHIC MODES
value: 160 x 9 pixels
- label: COLORS
value: Monochrome
- label: SOUND
value: Beeper
- label: SIZE / WEIGHT
value: 25.4 x 12.7 x 3.2 cm. - Weight 737g.
- label: I/O PORTS
value: HP-IL, 3 x ROM/RAM expansion ports
- label: BUILT IN MEDIA
value: Memory cards, 1.3 KB
- label: OS
value: Specific
- label: POWER SUPPLY
value: Battery pack or external AC adaptor
- label: PRICE
value: '75C: $995 - 75D: $1095'
tabs:
- adverts
- links
forum_thread: 626
adverts:
- title: FIRST AD
subtitle: ''
text: February 1983 - The real-size system picture occupied almost the full right page.
image: /media/museum/pubs/hp_75c_pub_1.jpg
links:
- title: Reverse-Engineering the HP-75C
url: http://www.fortitudine.com/~coryc/html/hp75c.shtml
text: Very informative page with useful & practical info such as keys functions, Basic commands and HP-IL operations
- title: The Museum of HP calculators
url: http://www.hpmuseum.org/hp75.htm
text: This site has a nice and complete page about the HP-75C/D. You can even order the original manual.
oc_id: 640
source:
url: https://web.archive.org/web/20230607231723/http://www.old-computers.com/museum/computer.asp?c=640
date: '2023-06-07'
---
The **HP-75C** was the first pocket computer ever produced by HP who wanted a pocket book format (10”x 5”) computer as powerful as a desktop. It can also be considered as the first organizer able to deal with a multiple alarms time schedule, to control real time peripherals and to memorize text files.
Its 48KB ROM contained a very complete Basic language and a light version of the spreadsheet Visicalc. Three slots allowed adding pre-programmed ROM modules (Maths, finance, word processor…)
It integrated a card reader. The cards was manually slipped front of the magnetic head. Each card could stock 1.3 KB of information on 2 tracks (650 bytes each). The card information coding allowed great variations of the reading speed, due to manual handling.
The HP-IL (Interface Loop) interface allowed connecting as far as 30 peripherals simultaneously on the HP-75C. Amid the peripherals, one could find a display unit, printers, a modem, a tape recorder and all the HP-IL standard peripherals.\
As always with HP, the manuals were very complete and pedagogical.
The **HP-75D** was released two years later. It added a wand and wand port. When used with the Bar Code ROM, the computer could scan CODE11, CODE39, UPC, and EAN codes. This made the computer useful for inventory control.