---
title: Hewlett Packard HP-9810
categories:
- Computers
types:
- Professional Computer
origins:
- U.S.A.
years:
- '1971'
cpus:
- Serial 16-bit
params:
  name: HP-9810
  company: /companies/hewlett-packard
  company_name: Hewlett Packard
  specs:
  - label: NAME
    value: HP-9810
  - label: MANUFACTURER
    value: Hewlett Packard
  - label: TYPE
    value: Professional Computer
  - label: ORIGIN
    value: U.S.A.
  - label: YEAR
    value: '1971'
  - label: BUILT IN LANGUAGE
    value: RPN (Reverse Polish Notation) based
  - label: KEYBOARD
    value: 75 keys in 3 parts
  - label: CPU
    value: Serial 16-bit
  - label: SPEED
    value: Unknown
  - label: RAM
    value: 51 registers and 500 program steps
  - label: ROM
    value: Unknown
  - label: TEXT MODES
    value: 3 lines of 15 numeric chars. Each line displays one register
  - label: GRAPHIC MODES
    value: None
  - label: SIZE / WEIGHT
    value: 49,5 (W) x 40,6 (D) x 17,8 (H) cm / 15.4 Kg
  - label: I/O PORTS
    value: Unknown
  - label: POWER SUPPLY
    value: Built-in power supply unit
  - label: PERIPHERALS
    value: RAM and ROM modules, Peripherals I/O connector
  - label: PRICE
    value: $2475
  tabs:
  - photos
  - adverts
  - links
  photos:
  - title: KEYBOARD
    subtitle: ''
    text: ''
    image: null
  adverts:
  - title: 1976 ADVERT
    subtitle: ''
    text: for the 9815, 9835 and 9830 systems
    image: null
  links:
  - title: Complete information about the HP-9810
    url: http://www.hpmuseum.org/hp9810.htm
    text: ''
  - title: HP Museum
    url: http://www.hpmuseum.net
    text: The best place about old HP computers and calculators.
  - title: Joe Rigdon pages
    url: http://www.classiccmp.org/hp/9800.htm
    text: More information about HP 98xx series
  - title: More details and pictures
    url: http://www.oldcalculatormuseum.com/hp9810a.html
    text: ''
  - title: My HP9810 repair job
    url: http://www.rheinfeld.de/andreas/9810.htm
    text: by Andreas Schumm
  comments:
  - author: bb
    date: Saturday 5th March 2016
    text: Our school had one of those in 1979 (including a A4-flatbed-plotter), but everyone wanted to use the newer PET 2001 and CBM 3002 systems. so I had that machine pretty much for myself.
  - author: Achim Alexandru (Romania)
    date: Tuesday 4th November 2003
    text: I have in my lab one of the Hp 9845b i believe without monitors.If want to get picture of the machine tell me.
  related:
  - /museum/hewlett-packard-hp-9816
  - /museum/hewlett-packard-hp-9825
  - /museum/hewlett-packard-hp-9826
  - /museum/hewlett-packard-hp-9830
  - /museum/hewlett-packard-hp-9836
  oc_id: 938
  source:
    url: https://web.archive.org/web/20230202005940/http://www.old-computers.com/museum/computer.asp?c=938
    date: '2023-02-02'
---

The HP-9810 was the successor of the **HP-9100**. Although it kept software compatibility, its internal hardware organisation was completely different. The core memory was replaced with volatile MOS RAM chips and the display used the new technology of 7-segment light emitting diodes (LED) instead of cathode-ray tube.

Arithmetic routines were stored in ROM and user programs in RAM. Several RAM extensions, specialized ROM modules and peripherals (paper tape reader/puncher, line printer, measuring instruments) could be connected to the basic model.

The standard version of this calculator included a **magnetic card reader** located directly behind the two yellow keys at the top-right in the keyboard. While a thermal printer was available as an option, it could only print numeric characters unless you had the Alphanumeric Printer ROM. The add-on ROMs for this machine came in the form of a block that plugged into the left side of the keyboard; each had its own specialized keys. You can see the edges of the ROM block in the picture; the 3x5 array of keys at the leftmost area of the keyboard is its top. It was common to have more than one ROM extension available in a single block, since you could only plug in one at a time.

With this first generation of programmable calculators, engineers eventually became independant from main frames and computer centers. They could write programs, save, recall and print them off-line; and even easily carry the computer from a place to another... it was a true revolution at the time.

<table> <tr> <td></td> <td>We need more info about this computer ! If you designed, used, or have more info about this system, please send us pictures or anything you might find useful.</td> <td></td> </tr> </table>