The Atari Message Information System (AMIS) was one of the first BBS (Bulletin Board System

Bulletin board system

A Bulletin Board System, or BBS, is a computer system running software that allows users to connect and log in to the system using a terminal program. Once logged in, a user can perform functions such as uploading and downloading software and data, reading news and bulletins, and exchanging...

) software packages available for the Atari 8-bit family

Atari 8-bit family

The Atari 8-bit family is a series of 8-bit home computers manufactured from 1979 to 1992. All are based on the MOS Technology 6502 CPU and were the first home computers designed with custom coprocessor chips...

 of computers.

The original AMIS BBS software was written in the BASIC programming language by members of MACE (Michigan Atari Computer Enthusiasts). The program included instructions for building a "ring detector" circuit for the board maintainer's modem

Modem

A modem is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data...

 to enable it to answer incoming calls – modems at the time were most often capable of making outgoing calls, but not receiving incoming ones.

A sector editor was required for the BBS maintainer to manually allocate message space on their disk, one hex

Hexadecimal

In mathematics and computer science, hexadecimal is a positional numeral system with a radix, or base, of 16. It uses sixteen distinct symbols, most often the symbols 0–9 to represent values zero to nine, and A, B, C, D, E, F to represent values ten to fifteen...

 byte

Byte

The byte is a unit of digital information in computing and telecommunications that most commonly consists of eight bits. Historically, a byte was the number of bits used to encode a single character of text in a computer and for this reason it is the basic addressable element in many computer...

 at a time.

The software was released into the public domain

Public domain

Works are in the public domain if the intellectual property rights have expired, if the intellectual property rights are forfeited, or if they are not covered by intellectual property rights at all...

, and was heavily modified by enthusiasts and BBS maintainers. As such, several versions of AMIS exist, including:

• Standard AMIS
• MACE AMIS – from the Michigan Atari Computer Enthusiasts
• Fast AMIS
• Carnival BBS
• Comet AMIS – by Matt Pritchard & Tom Johnson of Algonac, Michigan; originally designed for the MPP modem (which used the joystick port, not the regular I/O or 850 Interface ports. At the time this was a very popular low cost modem, that had no software written for it, until John Demar developed a driver to enable software to communicate with the joystick port as if it were the I/O port) and modified to be used with other types of standard modems. The final version featured many automated tasks, usage logs, passwords, private mail, multiple message bases and support for hard drives and MYDOS, and was on the cutting edge of AMIS/Atari 8-bit BBS technology.
• TODAMIS 1.0 – for 1030/XM301 modems, written in 1986 by Trent Dudley
• AMIS XM301 was a heavily modified version of AMIS written by one of the original AMIS programmers, Mike Mitchell (Baudville BBS - Garden City, MI), and newcomer Mike Olin (Molin's Den BBS, Northville, MI), written in Basic XE by Optimized System Software.