---
title: "The Atari Mega ST Fleet: Three Machines, Three Jobs"
section: "retro"
tags: "retro"
description: "How three Atari Mega ST computers ended up with completely different roles in a modern retro setup."
layout: base.njk
parent: "/retro/"
---
<h1>The Atari Mega ST Fleet: Three Machines, Three Jobs</h1>
<div class="detail-content">

<p>Somewhere along the way, "one Atari ST" turned into three Mega ST 4 machines plus a Mega ST 2. Rather than let them gather dust, each one got a clearly defined purpose, from untouched nostalgia piece to fully upgraded workstation.</p>

<h2>What Is an Atari Mega ST?</h2>
<p>The Atari Mega ST is a variant of Atari's 16/32-bit ST computer line, released in 1987 and aimed at business and desktop-publishing users. Compared to the standard 520 ST or 1040 ST, it comes in a low, flat desktop case with the floppy drive and motherboard separated from the keyboard, similar to a classic PC tower-and-keyboard setup. It shipped with a built-in Blitter chip for fast graphics operations, which the earliest 520/1040 ST models lacked, making it noticeably better suited for GEM-based desktop publishing software of the era.</p>
<p>Mega STs were sold as Mega 1 (1 MB RAM), Mega 2 (2 MB RAM) and Mega 4 (4 MB RAM), all expandable, and were commonly bundled with monochrome high-resolution monitors for DTP work with software like Calamus or PageStream. The separated case design makes internal expansion and modification considerably easier than on an all-in-one 1040 ST, which is one reason the Mega ST remains a popular base for retro computing projects like the ones documented on this site.</p>

<h2>The Lineup</h2>
<ul>
<li><strong>The <a href="/retro/mega-st-heirloom/">heirloom machine</a></strong>, kept as close to factory-original as possible, running the stock TOS 1.04 with a classic floppy drive and its own original Atari keyboard and mouse. Its job is to be a baseline reference: if something breaks on a modded machine, this one proves the fault isn't in the software.</li>
<li><strong>The <a href="/retro/mega-st-low/">"Low" machine</a></strong>, a bargain-bin Mega ST 4 rebuilt with a <a href="/retro/storm-cloudy/">Cloudy/Storm ST combo</a> for TOS switching and extra FastRAM, a <a href="/retro/gotek/">Gotek floppy emulator</a>, an <a href="/retro/ultrasatan/">UltraSatan</a> hard disk emulator, a <a href="/retro/sidecartridge/">SidecarTridge multi-device</a> for ROM, floppy, and Wi-Fi tricks, and a <a href="/retro/atari-networking-bbs/">Wi-Fi modem</a> for dialing into BBSs. It uses an original Atari keyboard and a <a href="/retro/mouster/">mouSTer</a> adapter with a USB mouse. This is the demo- and game-machine, optimized for fast disk-image swapping rather than serious productivity.</li>
<li><strong>The <a href="/retro/mega-st-high/">"High" machine</a></strong>, the workstation build. A <a href="/retro/monsterboard/">MonSTerBoard</a> adds 8MB of AltRAM, IDE storage, and flashable TOS (currently TOS 2.06), running Geneva for real multitasking. An <a href="/retro/et4000-experiment/">ET4000 graphics card</a> drives a dedicated monitor for higher resolutions. A <a href="/retro/netusb/">NetUSBee</a> adapter, an <a href="/retro/eiffel/">Eiffel interface</a> for a PS/2 keyboard and mouse, and a new <a href="/retro/stpsu/">STPSU</a> for clean, stable power round it out.</li>
<li><strong>The spare <a href="/retro/mega-st2/">Mega ST 2</a></strong>, a reserve and test machine, kept in largely original condition, used to safely test upgrades before they go into the "real" machines.</li>
</ul>

<h2>Machine Inventory</h2>
<p>All four machines were manufactured at Atari Taiwan Manufacturing Co. (indicated by the "A1" prefix in the serial numbers).</p>
<table>
<tr><th>Machine</th><th>Serial</th><th>Manufactured</th><th>Board</th></tr>
<tr><td>Mega ST 2</td><td>A1 7B 4010182</td><td>11/1987</td><td>CA200019 / C100167-001 Rev.5.0</td></tr>
<tr><td>Mega ST 4 "High"</td><td>A1 05 4009044</td><td>05/1990</td><td>—</td></tr>
<tr><td>Mega ST 4 "Low"</td><td>A1 08 4011143</td><td>08/1990</td><td>—</td></tr>
<tr><td>Mega ST 4 Heirloom</td><td>A1 08 4011015</td><td>08/1990</td><td>CA200019 / C100167-001 Rev.B</td></tr>
<tr><td>Keyboard (Heirloom)</td><td>A1 07 4085985</td><td>07/1990</td><td>CA200043-004</td></tr>
</table>

<h2>Extensions Not Yet Installed</h2>
<p>A few upgrades have been bought or built but aren't in a machine yet, either waiting to go in or kept as spares:</p>
<ul>
<li><strong>A second <a href="/retro/gotek/">Gotek floppy emulator</a></strong>, bought alongside the one fitted to the "Low" machine, still unbuilt and ready for another machine or as a spare.</li>
<li><strong>An <a href="/retro/eiffel-pico/">Eiffel Pico USB adapter</a></strong>, bought and configured but not yet installed, so I haven't decided which machine it will go into.</li>
<li><strong>A new <a href="/retro/sidecartridge/">SidecarTridge Multi-device</a> Revision 3</strong>, bought as an upgrade over the Revision 0 in use on the "Low" machine, still uninstalled until I decide where to put it.</li>
<li><strong>An <a href="/retro/acsi2stm/">ACSI2STM</a> adapter</strong>, bought but not yet in use anywhere, an alternative ACSI hard-disk emulator to the UltraSatan.</li>
<li><strong>An <a href="/retro/atari-vga/">ST2VGA Enhanced</a> adapter</strong>, an active RGB-to-VGA adapter bought as a spare, not currently in use.</li>
<li><strong>An original Atari STM-1 mouse converted with the <a href="/retro/laser-mouse/">laser board</a></strong>, upgraded but not currently in use.</li>
</ul>

<p class="note">Fun fact: two of the "problem" machines turned out to have nothing wrong with the boards at all, a badly soldered CPU socket and a leftover blitter patch bridge were the actual culprits. Moral of the story: check your solder joints twice before blaming the silicon.</p>

<p>For the full story of how it all started, see the <a href="/retro/computer-timeline/">computer timeline</a>.</p>
</div>