---
title: Olympia OP 544 / OP 644
categories:
- Computers
types:
- Pocket
origins:
- Japan
years:
- '1982'
cpus:
- HD61913 CMOS VLSI
params:
  name: OP 544 / OP 644
  image: /media/museum/photos/olympia_op544_system_s1.jpg
  company: /companies/olympia
  company_name: Olympia
  specs:
  - label: NAME
    value: OP 544 / OP 644
  - label: MANUFACTURER
    value: Olympia
  - label: TYPE
    value: Pocket
  - label: ORIGIN
    value: Japan
  - label: YEAR
    value: '1982'
  - label: END OF PRODUCTION
    value: Unknown
  - label: BUILT IN LANGUAGE
    value: Basic interpreter
  - label: KEYBOARD
    value: 53 keys with numeric keypad
  - label: CPU
    value: HD61913 CMOS VLSI
  - label: SPEED
    value: 455 kHz ceramic resonator used as system clock
  - label: RAM
    value: 1 KB (544 bytes for Basic programs) up to 2 KB
  - label: ROM
    value: 12 KB
  - label: TEXT MODES
    value: 1 line x 12 chars plus a 4 digit seven segment display part
  - label: GRAPHIC MODES
    value: None
  - label: COLORS
    value: Monochrome LCD
  - label: SOUND
    value: None
  - label: SIZE / WEIGHT
    value: 165 (W) x 71 (D) x 10 (H) mm / 116 g (with batteries)
  - label: I/O PORTS
    value: |-
      12-pin expansion port for printer and cassette interface\
      11-pin internal slot for memory module
  - label: POWER SUPPLY
    value: 2 x CR-2032 lithium batteries
  - label: PERIPHERALS
    value: CI-546 cassette interface, and all Casio PB-100 extensions
  - label: PRICE
    value: Unknown
  tabs:
  - photos
  photos:
  - title: 'FRONT VIEW #1'
    subtitle: ''
    text: ''
    image: /media/museum/photos/olympia_op544_system_s2.jpg
  - title: 'FRONT VIEW #2'
    subtitle: ''
    text: ''
    image: /media/museum/photos/olympia_op544_frontview_s1.jpg
  - title: OP-644
    subtitle: ''
    text: Here connected to the Olympia CI-546 cassette interface, same as the Casio FA-3 interface.
    image: /media/museum/photos/olympia_op644_system_s1.jpg
  oc_id: 1001
  source:
    url: https://web.archive.org/web/20230608080253/http://www.old-computers.com/museum/computer.asp?c=1001
    date: '2023-06-08'
---

The Olympia OP-544 was the same machine as the Casio [PB-100](/museum/casio-pb-100/).

The **OP-644** also had the same specifications, but featured a built-in 20-line thermal printer and a better keyboard layout with a true space bar. It was actually a Casio **FX-802P**