Before the likes of MS-DOS/IBM PC DOS, MacOS, Windows, GEM, IBM OS/2, Linux, MacOS X, another Operating System was very popular for professional computers: CP/M.

CP/M was first released in 1974 by Digital Research. This Operating System could run on many computers from different manufacturers, provided they met common characteristics (CPU, etc). CP/M computers had access to an impressive catalogue of software. Many well-known software products started with their CP/M version. Aimed at the small business market, freelancers, scientists or senior company executives, CP/M was very popular from the mid 1970s to the mid 1980s.

(See the "Buying a computer in 1982" article in this knowledge base for all the details)


FujiNet is a multi-peripheral emulator and WiFi network device for vintage computers. The FujiNet project began as a simple WiFi modem for the Atari 8-Bit line of computers and quickly grew into a super peripheral emulating many devices including floppy disk drives, printers, cassette tape player/recorder, modem and the all new network device.

My personal opinion is that FujiNet and SIDE3 are now indispensable to all fans of Atari 8-bit computers. Voilà, That's it.

(Visit the official web site: https://fujinet.online)

Objective and requirements

The Atari's MOS 6502 microprocessor cannot run CP/M natively; CP/M requires a Zilog Z80 or an Intel 8080/85. However, the FujiNet chipset is powerful enough to run CP/M on an emulated Z80.

Therefore, FujiNet will run CP/M and the Atari computer will behave like a remote console connected to the CP/M computer via a pseudo-modem connection. In other words, FujiNet will run CP/M, all controlled by the Atari's keyboard and displayed on the Atari's video monitor.

All you need is a FujiNet (obviously), and some easy to find software. I've provided some links at the end of this article.

Step 1: set-up FujiNet


  1. Update your FujiNet to the latest firmware
  2. Connect to the FujiNet web interface to check that:
    1. The modem is present
    2. The modem is activated
  3. In the root of the FujiNet MicroSD card, create the following folders structure{1} in capital letters/uppercase: /CPM/A/0
  4. Unzip & Copy the contents of the CPM-A-0-folder.zip file with the system files on the FujiNet MicroSD card, obviously in the /CPM/A/0 folder

{1} The last folder is the number zero: CPM/Letter A/Number Zero

Nothing more to do on the FujiNet side. The RunCPM software/daemon is running and waiting for a command.

Optional. If you want to add/mount "CP/M diskettes", just copy them to users 0..9 and to drives A..M:

Step 2: on the Atari

Proceed in this order:

  1. Launch a Smart Terminal which preferably supports 80 columns
    1. Take, for example, ICE-T that you can download from https://atariage.com/forums/topic/217539-ice-t-xe-276-released
    2. Set FujiNet to boot from the ICE-T .atr software diskette
    3. Press "OPTION" for 5 seconds while you turn the Atari on, to disable the internal BASIC in the computers that have it
    4. MyDos starts but the R: driver is missing
    5. Since FujiNet emulates an Atari 850 interface, copy (duplicate & rename) the "ATARI850.HND" file into "RS232.COM" in the same location as "ICET.COM"
    6. Launch ICET.COM — it will launch "RS232.COM" automatically
  2. Put the terminal in this mode: 9600,8,n,1
  3. Type ATCPM and press "RETURN"
  4. FujiNet reacts and sends the CP/M output to the screen: the A0> prompt appears!

Useful web sites & resources

Those sites will be useful if you start from scratch:


Before launching ICE-T

Before launching ICE-T

ICE-T Smart Terminal

ICE-T Smart Terminal

CP/M is running...

CP/M is running...

Special thanks to Jerome Delsarte for the technical information this article.

Knowledge base article: kb-hardware-0004-atari-8bit-digital-research-cpm-fujinet
REV. 005.

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