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Thomas Cherryhomes will be speaking at the Vintage Computer Festival East, in New Jersey, on May 18th, to show off IRATA.ONLINE at 3:20pm Eastern Time. There will be an introduction, a demonstration, and Q&A period.

VCF East Website


IRATA.ONLINE user jthiele / atari will be present at Classic Game Fest in Austin, Texas on July 27th and 28th, 2018 to demonstrate the service. An Atari 800XL will be available as a terminal for interested people, running a demonstration that can be interrupted at any point to sign up for the service.


The next two demo meets are:

Saturday, May 5, 2018 - 2pm - 4pm CDT

Jitsi link

Sunday, May 6, 2018 - 10am - 12:00pm CDT

Jitsi link

Fun, Social, Creative, Retro.

IRATA.ONLINE is provided for the benefit of retro-computing users to have a place to socialize, and develop interesting multi-user, interactive, and graphical games and social applications. It descends from the historical PLATO system, a massive time-sharing system that lasted from 1962 until NovaNET was closed in 2015. Wikipedia entry.

It is vital that communities grow, and to that end, IRATA.ONLINE is part of a rebirth of the PLATO system that started with the launching of Cyber1.org in 2004, and is the direct result of the efforts of that community to provide a distribution of the PLATO system that could be run on other systems. IRATA.ONLINE was initially intended to provide users of Atari 8-bit computer systems a customized experience that was easy to use. It is hoped that with the introduction of more PLATO terminals for other platforms that IRATA.ONLINE's reach can extend even further.

Where will it go? Who knows. This is an experiment to provide something better than a BBS, by making something that is not only multi-user, but provides a complete social development experience for its users.


IRATA.ONLINE is a PLATO based system, which has the following pervasive features:

  • Multi-User
  • Graphical, with combinations of text, line graphics, and custom character sets, as well as 24-bit color (on supported terminals)
  • Touch screen support
  • Terminals available for PC, Mac, Linux, Atari 8-bit, and soon Android and iOS.
  • Multi-Player Games
  • Notes files for social posting on a growing variety of topics
  • Talk with other users, anywhere in the system, even in games!
  • Help with tutorials to introduce you to the system.
  • Development environment to make new programs for the system.
  • Lots of existing educational content, because it's a PLATO system.
  • Screen sharing facilities, even with multiple participants!
  • and more!


If you have a PC, Mac, or Linux System:

If you have a PC or Mac that is already internet connected, all you need is the PTERM software, available from Cyber1.org

Download PTERM 5.0.8 for Windows

Download PTERM 5.0.9 for MacOS

Download PTERM 5.0.8 Source Code

(Linux binary builds coming soon. Setting up Package Repositories!)

If you have an Atari 8-bit Computer

If you have an Atari 8-bit computer, you will need:

  • Atari 8-bit Computer with at least 48K of memory
  • Atari 850 Serial Interface
  • Something to bridge RS232 to TCP, solutions include:
    • Raspberry Pi running tcpser
    • Lantronix UDS terminal device
  • Any cabling you need to connect it all together.
  • A copy of The Learning Phone cartridge (patched for cyber1 and IRATA.ONLINE), which can be procured from here. The manual is here.
  • A Flash cartridge, e.g. from AtariMAX.COM

If you have something else?

We not only provide a complete protocol specification, but also two complete implementations in C, as well as the source code to the above Atari PLATO cartridge.

More details in the TECH section.


To connect to IRATA.ONLINE, use the following connection information:

  • Port: 8005 (ASCII Protocol)


Here are some example screenshots showcasing the IRATA.ONLINE experience. The majority of these screenshots were taken with the PTERM emulator linked to above. PTERM provides an authentic PLATO experience, either in pure orange and black, or with color! Some screenshots of other terminal emulators, such as the Atari PLATO cartridge, are also included.


Shown here is a video providing an overview of IRATA.ONLINE, and its most basic and pervasive features. We log onto the system using both the PTERM and Atari clients, and walk through the various menus, showing quickly how notes (and personal notes) work, as well as show a quick glance of the games available, and a quick introduction to the unique programming environment available on PLATO systems.

More Videos...


How do I make a terminal for this service?

The Protocol that IRATA.ONLINE uses is an ASCII based protocol developed for PLATO. it is ASCII in that it uses 7-bit characters and does not use the 8th bit of the byte. The protocol is completely documented in the "s0ascers" document, provided both below and accessible using either author mode or Go in the menu system. If you wish to make terminal software to access this service, this document is most useful.

S0ASCERS Document (HTML format)

S0ASCERS Document (ASCII text format)

Example Terminal Code

To help foster adoption of the service, alongside the protocol implementation documentation above, and the pterm source code, also above. Steve Peltz also provided example implementations of a classic 68K Macintosh terminal (MacPAD) and a Sun SPARC terminal (XPad), both of these are sample implementations written in easy to understand C, that can be brought over to bootstrap other terminal program efforts. A big thank you to Steve Peltz.

MacPAD Source Code (1990)

SPARCPAD Source Code (1990)

Atari PLATO Cartridge (The Learning Phone) Source Code at github.

WIP code for a Commodore 64 PLATO Terminal written in CC65.

WIP code for an Atari ST PLATO Terminal written in Pure C

Micro Tutor Source Code

While not needed, it is possible for PLATO terminals to receive code from IRATA and execute it locally, possibly while interacting with code running on IRATA. A Micro Tutor interpreter exists within PTerm 6.0, and thus can be used to run Micro-Tutor lessons, and with appropriate implementations on other processors (6502, 6809, 68000, etc.), Micro-TUTOR could be extended to a wide variety of retro-computing systems. Source code in assembly for the Z80 Micro-Tutor interpreter is below:

Micro-PLATO Source Code extracted from IRATA's filesystem

Complete Level-2 Micro-TUTOR source code

The core interpreter for Micro-TUTOR level 4

How do I write software for this service?

IRATA.ONLINE like all PLATO systems, utilizes the TUTOR language for the majority of its programs and lessons. It is a very simple language to learn, and is designed to leverage the unique aspects of the service. The editor, debugger, and visual editors needed to make excellent programs for this service, are all built in, and available to users that ask for an Author sign-on.

There is also the =0introtut= lesson available from the Help menu and in author mode, as well as the =aids= lesson, which serves as a reference guide.

In addition, the fine folks at bitsavers.org and control-data.info provided a copy of The Tutor Language in PDF format, so you can teach yourself TUTOR quickly!

The Tutor Language (PDF Format)

Introduction to Tutor (PDF Format)