---
title: "Mega ST 4 High: The Workstation"
section: "retro"
tags: "retro"
description: "The high-end Mega ST 4 workstation with MonSTerBoard, ET4000, NetUSBee, Eiffel interface, a modern STPSU and patched TOS 2.06, running Geneva."
layout: base.njk
parent: "/retro/"
---
<h1>Mega ST 4 High: The Workstation</h1>
<div class="detail-content">

<p>Received for free in 2026, this Mega ST 4 was fully rebuilt and is today my primary workstation. It's the most capable machine in the fleet, running Geneva as a real multitasking environment.</p>

<h2>Details</h2>
<p>Serial: A1 05 4009044 · Manufactured May 1990</p>

<h2>Work Performed</h2>
<ul>
<li><strong>Blitter patch</strong>, removed an existing patch and carefully bridged the severed trace with wire, verifying it with a continuity test. The installed blitter (marked S9012 / MM9092V, a National variant from week 12/1990) belongs to an unproblematic batch where the classic Mega ST blitter patch is generally no longer needed.</li>
<li><strong>CPU socket</strong>, soldered in a 68000 socket and checked all connections to the board with a multimeter.</li>
<li><strong>TOS</strong>, removed the onboard TOS from its sockets to avoid conflicts with the external flash TOS on the MonSTerBoard.</li>
<li><strong>Power supply</strong>, replaced with a modern <a href="/retro/stpsu/">STPSU</a> for clean, stable power, which matters especially for the ET4000.</li>
</ul>

<h2>MonSTerBoard</h2>
<p>The <a href="/retro/monsterboard/">MonSTerBoard</a> is plugged onto the 68000 socket, with jumpers set so TOS 2.06 is used from its flash. The TOS 2.06 is patched to skip the memory check, which noticeably speeds up the boot process. KAOS TOS is also installed on the flash, though currently I always run Geneva under TOS 2.06. No TOS switcher is wired up yet, so the machine is fixed to TOS 2.06 for now. The MonSTerBoard provides up to 8 MB of AltRAM (TT-compatible range, activated via <code>m_altram.prg</code>), an IDE interface for CF/IDE storage, and a flash ROM holding multiple TOS images. I boot from a 1 GB CompactFlash card over IDE, which is noticeably faster than an ACSI drive.</p>

<h2>Peripherals in Use</h2>
<ul>
<li><strong><a href="/retro/et4000-experiment/">ET4000 graphics card</a></strong> in the MegaBus, providing higher resolutions and better display quality with Geneva/NVDI, driving a dedicated monitor.</li>
<li><strong><a href="/retro/netusb/">NetUSBee</a></strong> on the ROM port, giving real internet via STinG and a USB port for FAT16 data exchange with Windows.</li>
<li><strong><a href="/retro/eiffel/">Eiffel interface</a></strong> for a PS/2 keyboard and mouse, a much better typing feel than the original hardware.</li>
<li><strong>Self-built <a href="/retro/atari-vga/">VGA adapter</a></strong>, a short cable to a small box with the VGA connector and mono/color switch, since a standard adapter would block the ET4000's VGA output.</li>
</ul>

<h2>Role</h2>
<p>Workstation machine with multitasking (Geneva), AltRAM, IDE/CF boot, USB and network connectivity, and high-resolution display. My primary system for programming and productive work.</p>

<h2>Gallery</h2>
<img src="high-1.jpg" alt="The Mega ST 4 High machine" width="640" height="640" loading="lazy">
<p class="caption">The Mega ST 4 "High" workstation.</p>
<img src="high-2.jpg" alt="Mega ST 4 High internal view" width="640" height="640" loading="lazy">
<p class="caption">Inside the "High" machine.</p>
<img src="high-3.jpg" alt="Mega ST 4 High detail" width="640" height="853" loading="lazy">
<p class="caption">A detail of the "High" setup.</p>
<img src="high-4.jpg" alt="Mega ST 4 High expansion" width="640" height="480" loading="lazy">
<p class="caption">Expansion boards in the "High" machine.</p>
<img src="high-5.jpg" alt="Mega ST 4 High close-up" width="640" height="640" loading="lazy">
<p class="caption">Close-up of the "High" machine.</p>
<img src="high-6.jpg" alt="Mega ST 4 High running" width="640" height="480" loading="lazy">
<p class="caption">The "High" machine in operation.</p>
<img src="high-7.jpg" alt="Mega ST 4 High setup" width="640" height="480" loading="lazy">
<p class="caption">The "High" workstation setup.</p>
<img src="high-8.jpg" alt="Mega ST 4 High board" width="640" height="640" loading="lazy">
<p class="caption">Board detail of the "High" machine.</p>
<img src="high-9.jpg" alt="Mega ST 4 High final" width="640" height="480" loading="lazy">
<p class="caption">The finished "High" machine.</p>

</div>