---
title: Gespac Gescomp 720 / 730
categories:
- Computers
types:
- Professional Computer
origins:
- Swiss
years:
- '1982'
cpus:
- '6800'
params:
  name: Gescomp 720 / 730
  image: /media/museum/photos/gespac_gescomp-720-730_1s.jpg
  company: /companies/gespac
  company_name: Gespac
  specs:
  - label: NAME
    value: Gescomp 720 / 730
  - label: MANUFACTURER
    value: Gespac
  - label: TYPE
    value: Professional Computer
  - label: ORIGIN
    value: Swiss
  - label: YEAR
    value: ? 1982
  - label: KEYBOARD
    value: Full stroke keyboard with numeric keypad and function keys
  - label: CPU
    value: 6800 / 6809 / Z80
  - label: RAM
    value: 64 KB
  - label: GRAPHIC MODES
    value: 256x192
  - label: COLORS
    value: 'yes'
  - label: SOUND
    value: unknown
  - label: BUILT IN MEDIA
    value: 2 x 5.25'' disk drives (400 KB or 800 KB each) + optional 5 MB Winchester hard disk
  - label: OS
    value: GESDOS (6800-6809), CP/M 2.2, GESBOS (Z80)
  - label: POWER SUPPLY
    value: Built-in PSU
  tabs:
  - photos
  - adverts
  forum_thread: 1305
  photos:
  - title: GESCOMP 720-730
    subtitle: ''
    text: ''
    image: null
  - title: GESCOMP
    subtitle: ''
    text: |-
      Model not really known, but this is one is based on a 6809 CPU.

      Thanks to F1FCO for this picture
    image: null
  adverts:
  - title: FRENCH ADVERT (JUNE 1982)
    subtitle: ''
    text: ''
    image: null
  oc_id: 1340
  source:
    url: https://web.archive.org/web/20230609210709/http://www.old-computers.com/museum/computer.asp?c=1340
    date: '2023-06-09'
---

GESPAC SA was a Swiss company who designed the G-64/96 Bus in 1979. This interface bus concept provides a simple way to interface microprocessor modules with memory and peripheral modules on a parallel bus. The G-64/96 Bus uses a simple, yet modern and powerful interface scheme which allows a higher level of functionality from the single height Eurocard form factor. The low overhead of the G-64/96 Bus interface greatly eases the design of custom boards by the User. This is why, even many years after its invention, the G-64/96 Bus is still widely used in the industry.

The G-64/96 bus concept supports the following features:

\- Processors manufacturer independent interface - 8 and 16-bit data transfers - Up to 32 Mbyte addressing capability - Multiple DMA operations - Non-vectored and vectored interrupts - A parallel decentralized arbitration scheme (G-96: multi-processors) - A message passing mechanism (G-96: multi-processors)

In 1982, GESPAC SA released two computers based on the G64 Bus: Gescomp 720 and Gescomp 730, mainly targeted as industrial use.

These modular systems could use a wide variety of G64 compatible boards. They could be powered by a 68000/6809 CPU, or a ZX80 CPU or a 8085 CPU !

Depending on the CPU installed, the computer could run different operating systems:

\- 68800-6809 -> GESDOS, offering an editor, macro-assembler, Basic, Graphical Basic, 6809 emulator, IEEE 4888, Centronics printer interface\
\- Z80-8085 -> CP/M 2.2, mainly used for wordprocessing and CP/M tools\
\- Z80 -> GESBOS, offering a GESBOL interpreter, GESBOL compilator + many professional applications.

Each computer had 64 KB RAM and came in different mass storage configurations:\
\- two 5.25'' floppy disk drives (400 KB each)\
\- two 5.25'' floppy disk drives (800 KB each)\
\- one 5.25'' floppy disk drive + 5 MB Winchester hard disk

Apparently the computer had a colour graphic card offering 512x256 pixels resolution.

In 1982, GESPAC NETWORK was available. It was a communication network solution for Gespac Bus based systems. Up to 32 computers could be connected, to a maximum distance of 300m and with a transmission speed rate of 800 KB/s.

<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>