Note SM124 and MegaFile HDDs still stored at parents' basement

eleventy.config.js

@@ -34,6 +34,19 @@ module.exports = function (eleventyConfig) {
   // Retro: ET4000 page images
   eleventyConfig.addPassthroughCopy("retro/et4000-experiment/*.jpg");
 
+  // Retro: STPSU page images + manual PDF
+  eleventyConfig.addPassthroughCopy("retro/stpsu/*.pdf");
+
+  // Retro: page-specific photo galleries (MonSTerBoard, Gotek, Eiffel, STPSU)
+  eleventyConfig.addPassthroughCopy("retro/monsterboard/*.jpg");
+  eleventyConfig.addPassthroughCopy("retro/gotek/*.jpg");
+  eleventyConfig.addPassthroughCopy("retro/eiffel/*.jpg");
+  eleventyConfig.addPassthroughCopy("retro/stpsu/*.jpg");
+  eleventyConfig.addPassthroughCopy("retro/acsi2stm/*.jpg");
+  eleventyConfig.addPassthroughCopy("retro/atari-vga/*.jpg");
+  eleventyConfig.addPassthroughCopy("retro/laser-mouse/*.jpg");
+  eleventyConfig.addPassthroughCopy("retro/mega-st-high/*.jpg");
+
   // Root-level shared assets
   eleventyConfig.addPassthroughCopy({ "shared/base.css": "shared-base.css" });
   eleventyConfig.addPassthroughCopy({ "shared/favicon/hub.svg": "favicon.svg" });

retro/acsi2stm/index.njk

@@ -0,0 +1,37 @@
+---
+title: "ACSI2STM: Atari ST Hard Drive Emulator"
+section: "retro"
+tags: "retro"
+description: "An ACSI to SD card hard drive emulator for the Atari ST based on an STM32 microcontroller, bought but not yet in use."
+layout: base.njk
+parent: "/retro/"
+---
+<h1>ACSI2STM: Atari ST Hard Drive Emulator</h1>
+<div class="detail-content">
+
+<p>I bought an ACSI2STM adapter but haven't put it into a machine yet. It's a hard drive emulator for the Atari ST built around an inexpensive STM32 microcontroller and an SD card, an open-source project by retro16.</p>
+
+<h2>What it does</h2>
+<p>ACSI2STM connects to the ACSI (DB19) port at the back of the Atari ST and emulates a hard drive. It can work in three ways:</p>
+<ul>
+<li><strong>Mount SD cards</strong>, standard SD/SDHC/SDXC cards (FAT16/FAT32/ExFAT) appear on the Atari.</li>
+<li><strong>Expose raw SD cards</strong> as ACSI hard disks connected to the Atari.</li>
+<li><strong>Expose disk image files</strong> as hard disks connected to the Atari.</li>
+</ul>
+<p>It also provides an UltraSatan-compatible real-time clock if you add a simple 3V lithium battery such as a CR2032.</p>
+
+<h2>Hardware</h2>
+<p>The hardware is a custom PCB that can be ordered preassembled directly from JLCPCB. The board attaches straight to the DB19 port at the back of the ST and has three microSD card slots, with the firmware supporting up to five SD card readers. It's designed to be easy to build, extremely cheap, reliable and safe for the vintage machine. The project is mature and considered finished, with both software and hardware complete. It can even work on STs with broken DMA chips using the PIO firmware.</p>
+
+<h2>My Setup</h2>
+<p>I bought an ACSI2STM adapter, but it isn't in use anywhere yet, so it sits among my other uninstalled extensions. The <a href="/retro/ultrasatan/">UltraSatan</a> currently provides the ACSI hard-disk storage on the "Low" machine, so the ACSI2STM would be an alternative or a spare for another machine.</p>
+
+<h2>Gallery</h2>
+<img src="acsi2stm.jpg" alt="The ACSI2STM adapter" width="640" height="640">
+<p class="caption">The ACSI2STM adapter, not yet installed.</p>
+
+<h2>Sources</h2>
+<ul>
+<li><a href="https://github.com/retro16/acsi2stm" target="_blank">ACSI2STM - GitHub (project page)</a></li>
+</ul>
+</div>

retro/atari-mega-st-fleet/index.njk

@@ -11,12 +11,16 @@ parent: "/retro/"
 
 <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 heirloom machine</strong>, kept as close to factory-original as possible, running the stock TOS 1.04 and a classic floppy drive. 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 "Low" machine</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. This is the demo- and game-machine, optimized for fast disk-image swapping rather than serious productivity.</li>
-<li><strong>The "High" machine</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 and an <a href="/retro/eiffel/">Eiffel interface</a> for a PS/2 keyboard and mouse round it out, with the original Atari keyboard and mouse now on the "Low" machine.</li>
-<li><strong>The spare Mega ST 2</strong>, a reserve and donor machine, kept in largely original condition, used to safely test upgrades before they go into the "real" machines.</li>
+<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>Extensions Not Yet Installed</h2>
@@ -25,6 +29,9 @@ parent: "/retro/"
 <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>

retro/atari-vga/index.njk

@@ -0,0 +1,36 @@
+---
+title: "Atari to VGA: Getting the ST Onto a Modern Monitor"
+section: "retro"
+tags: "retro"
+description: "How I connect the Atari Mega ST machines to modern VGA monitors, with three different RGB-to-VGA adapters."
+layout: base.njk
+parent: "/retro/"
+---
+<h1>Atari to VGA: Getting the ST Onto a Modern Monitor</h1>
+<div class="detail-content">
+
+<p>To get the Atari ST onto a modern monitor, I use RGB-to-VGA adapters. I have three of them: a passive MCSWITCH adapter on the "Low" machine, a self-built adapter on the "High" machine, and a newer active ST2VGA Enhanced that isn't in use yet.</p>
+
+<h2>The MCSWITCH (Low machine)</h2>
+<p>The <a href="/retro/atari-mega-st-fleet/">Mega ST 4 "Low"</a> uses an MCSWITCH adapter (ATARI Monochrome &amp; Color VGA Adapter) by Olivier Gossuin. It shows all three ST resolutions on a suitable VGA monitor, with a switch for mono and color. The version documented on <a href="http://www.albersdoerfer.de/erweiterungen/stvga.htm" target="_blank">albersdoerfer.de</a> also has an A/V connector and volume buttons, but mine is an older revision without the volume buttons and with a slightly different look. I can't find my exact version at Olivier's anymore, nor a newer one, so the adapter I have is a bit of a rare older revision.</p>
+
+<h2>The self-built adapter (High machine)</h2>
+<p>The <a href="/retro/atari-mega-st-fleet/">Mega ST 4 "High"</a> uses a self-built adapter. I had to build my own because every off-the-shelf adapter blocks the VGA slot of the <a href="/retro/et4000-experiment/">ET4000</a> card, since both connectors sit at the same spot on the machine. My solution is a short cable leading to a small box, which carries the VGA connector and the mono/color switch, so the ET4000's own VGA output stays accessible. I followed the guide at <a href="https://pest.atari.org/www.logicsays.com/atari/mono/docs/atari_vga.htm" target="_blank">pest.atari.org</a> to build the RGB-to-VGA adapter itself.</p>
+
+<h2>The ST2VGA Enhanced (not yet in use)</h2>
+<p>I also bought a new active <a href="https://sidecartridge.com/products/st2vga-atari-st/" target="_blank">ST2VGA Enhanced</a> from SidecarTridge, but it isn't in use yet. Unlike the passive adapters, the Enhanced adds an active amplifier and filter stage for early or noisy Atari machines, and carries its own +5V supply over micro-USB. It's designed for machines with weak video output, visible "jailbars", or picky LCD inputs that fail to lock to the signal. I want to try it on the "Low" machine to see whether it cleans up the output on the <a href="https://www.amazon.de/dp/B0957KH8X7/" target="_blank">Dell SE2722HX</a>, which currently shows some faint vertical stripes, and hopefully removes them.</p>
+
+<h2>A note on monitors</h2>
+<p>Passive RGB-to-VGA adapters output the Atari's native timings, so color modes (ST Low and ST Medium) need a monitor that can lock to a 15 kHz horizontal sync signal. See my <a href="/retro/atari-monitor-compatibility/">monitor compatibility</a> page for which modern panels actually work. Mono mode (ST High) works on any standard VGA display.</p>
+
+<h2>Gallery</h2>
+<img src="stvga-low.jpg" alt="The MCSWITCH VGA adapter connected to the Atari" width="640" height="640">
+<p class="caption">The MCSWITCH adapter on the Mega ST 4 "Low" machine.</p>
+
+<h2>Sources</h2>
+<ul>
+<li><a href="http://www.albersdoerfer.de/erweiterungen/stvga.htm" target="_blank">MCSWITCH (ATARI Monochrome &amp; Color VGA Adapter) - albersdoerfer.de</a></li>
+<li><a href="https://pest.atari.org/www.logicsays.com/atari/mono/docs/atari_vga.htm" target="_blank">Atari to VGA adapter build guide - pest.atari.org</a></li>
+<li><a href="https://sidecartridge.com/products/st2vga-atari-st/" target="_blank">ST2VGA Adapter - SidecarTridge (product page)</a></li>
+</ul>
+</div>

retro/eiffel/index.njk

@@ -28,7 +28,11 @@ parent: "/retro/"
 <p>Original Atari keyboards are getting rare and expensive. The Eiffel is a cheap, modern alternative that brings a standard PS/2 keyboard and mouse to the machine, along with the two joystick ports the original keyboard had. It also gives a much better typing feel: I use a Cherry PS/2 keyboard, which is far more pleasant to type on than the original, and a Logitech PS/2 mouse that tracks noticeably better than the original Atari STM1 mouse. It makes the workstation far more practical to use day to day. The older Eiffel versions were originally built and sold by Lyndon Amsdon, with the design documented on the <a href="https://hardware.atari.org/eiffel/index.htm" target="_blank">Atari Hardware Guide</a>, and the project history is covered in the <a href="https://wiki.newtosworld.de/index.php?title=Eiffel_Interface" target="_blank">Atari Wiki</a>.</p>
 
 <h2>My Setup</h2>
-<p>In my Mega ST 4 "High" machine the Eiffel connects the PS/2 keyboard and mouse, keeping the workstation fully usable alongside the <a href="/retro/monsterboard/">MonSTerBoard</a>, <a href="/retro/et4000-experiment/">ET4000</a> and <a href="/retro/netusb/">NetUSBee</a>. The original Atari keyboard and mouse are now used with the "Low" machine.</p>
+<p>In my Mega ST 4 "High" machine the Eiffel connects the PS/2 keyboard and mouse, keeping the workstation fully usable alongside the <a href="/retro/monsterboard/">MonSTerBoard</a>, <a href="/retro/et4000-experiment/">ET4000</a> and <a href="/retro/netusb/">NetUSBee</a>. The original Atari keyboard is now used with the "Low" machine, which pairs it with a <a href="/retro/mouster/">mouSTer</a> and a USB mouse.</p>
+
+<h2>Gallery</h2>
+<img src="eiffel-ps2.jpg" alt="The Eiffel PS/2 adapter without its case" width="480" height="640">
+<p class="caption">The Eiffel PS/2 adapter, shown here without its case.</p>
 
 <h2>Sources</h2>
 <ul>

retro/gotek/index.njk

@@ -33,6 +33,14 @@ parent: "/retro/"
 <p>One of the Gotek emulators is installed internally in my Mega ST 4 "Low" machine, giving it reliable disk-image storage on a USB stick alongside the <a href="/retro/storm-cloudy/">Cloudy/Storm ST combo</a>, the <a href="/retro/sidecartridge/">SidecarTridge</a> and the <a href="/retro/atari-networking-bbs/">Wi-Fi modem</a>. The second Gotek is still unbuilt, waiting to go into another machine or to serve as a spare.</p>
 <p>For the internal mount I printed a <a href="https://www.thingiverse.com/thing:2664753" target="_blank">Gotek case from Thingiverse</a> that fits in the floppy bay. I used this to relocate the Storm/Cloudy TOS switcher: the 2-way switch is mounted in a slot at the front of the printed case, right where the floppy opening is. So the TOS switcher now sits at the front of the floppy bay, which meant no drilling into the case at all, and there was already space there for it.</p>
 
+<h2>Gallery</h2>
+<img src="gotek-switch-2.jpg" alt="The relocated TOS switcher at the front of the Gotek case" width="640" height="640">
+<p class="caption">The relocated TOS switcher at the front of the printed Gotek case, a clear view of how it sits in the floppy bay.</p>
+<img src="gotek-switch.jpg" alt="Gotek with the relocated TOS switcher in the printed case" width="640" height="480">
+<p class="caption">The Gotek in the 3D-printed case, with the relocated TOS switcher visible at the front.</p>
+<img src="gotek-back.jpg" alt="Gotek floppy emulator rear view" width="640" height="480">
+<p class="caption">The Gotek rear view.</p>
+
 <h2>Sources</h2>
 <ul>
 <li><a href="https://www.chzsoft.de/site/hardware/usb-stick-floppy-emulator-am-atari-st/" target="_blank">USB-Stick-Floppy-Emulator am Atari ST - CHZ-Soft (installation guide)</a></li>

retro/index.njk

@@ -10,39 +10,69 @@ sections:
       - title: "🖥️ The Mega ST Fleet"
         summary: "Three Mega ST 4 machines and a Mega ST 2, each with a clearly defined role from heirloom to workstation."
         href: "/retro/atari-mega-st-fleet/"
-      - title: "⚡ ET4000 in the Mega ST"
-        summary: "Adding higher resolutions to the Mega ST 4 'High' via a STGA adapter and an ET4000 card, and what it took to get it working."
-        href: "/retro/et4000-experiment/"
-      - title: "📺 Monitor Compatibility"
-        summary: "The 15kHz problem explained, and which modern monitor panels actually cooperate with Atari colour modes."
-        href: "/retro/atari-monitor-compatibility/"
-      - title: "🔌 Wi-Fi Modem & BBS"
-        summary: "Dialing into telnet bulletin board systems from the Mega ST 4 'Low' using dhansel's WifiModem and terminal software."
-        href: "/retro/atari-networking-bbs/"
+      - title: "🎮 Mega ST 4 Low"
+        summary: "The bargain-bin Mega ST 4 rebuilt as a LowRes demo and games machine with Cloudy/Storm ST, Gotek, UltraSatan and more."
+        href: "/retro/mega-st-low/"
+      - title: "🖥️ Mega ST 4 High"
+        summary: "The high-end workstation with MonSTerBoard, ET4000, NetUSBee, Eiffel and STPSU, running Geneva."
+        href: "/retro/mega-st-high/"
+      - title: "🔧 Mega ST 2"
+        summary: "The spare and test machine for the rest of the fleet."
+        href: "/retro/mega-st2/"
+      - title: "🏛️ Heirloom Mega ST 4"
+        summary: "My father's original Mega ST 4, kept factory-original as a baseline reference."
+        href: "/retro/mega-st-heirloom/"
       - title: "🌀 Storm ST & Cloudy ST"
-        summary: "Adding 8 MB Alt-RAM and flashable TOS to the Mega ST, switching between EmuTOS and TOS 1.04."
+        summary: "Adding 8 MB Alt-RAM and flashable TOS to the Mega ST, switching between EmuTOS and iTOS 1.04."
         href: "/retro/storm-cloudy/"
       - title: "🧠 MonSTerBoard"
         summary: "How the MonSTerBoard turns the Mega ST 4 'High' into a workstation with 8 MB TT-RAM, dual IDE and flashable TOS."
         href: "/retro/monsterboard/"
-      - title: "🌐 NetUSBee"
-        summary: "Real internet via STinG and a USB port for FAT16 data exchange with Windows on the Mega ST 4 'High'."
-        href: "/retro/netusb/"
-      - title: "💳 SidecarTridge Multi-device"
-        summary: "An apps platform in a cartridge, adding Wi-Fi, ROM emulation and floppy/hard-disk images to the Mega ST 4 'Low'."
-        href: "/retro/sidecartridge/"
+      - title: "📖 TOS Explained"
+        summary: "A short explanation of TOS, the operating system behind every Atari ST, and the versions that matter today."
+        href: "/retro/tos/"
       - title: "💾 Gotek Floppy Emulator"
         summary: "Replacing floppy drives with cheap Gotek emulators and HxC firmware, using USB stick disk images on the Mega ST 4 'Low'."
         href: "/retro/gotek/"
       - title: "💽 UltraSatan"
         summary: "Giving the Mega ST 4 'Low' a real ACSI hard disk on an SD card with the UltraSatan Mini from Lotharek."
         href: "/retro/ultrasatan/"
+      - title: "💽 ACSI2STM"
+        summary: "An open-source ACSI to SD card hard drive emulator for the Atari ST. Bought, not yet in use."
+        href: "/retro/acsi2stm/"
+      - title: "💳 SidecarTridge Multi-device"
+        summary: "An apps platform in a cartridge, adding Wi-Fi, ROM emulation and floppy/hard-disk images to the Mega ST 4 'Low'."
+        href: "/retro/sidecartridge/"
       - title: "⌨️ Eiffel Interface"
         summary: "Connecting a PS/2 keyboard, mouse and joysticks to the Mega ST 4 'High' with the Eiffel adapter."
         href: "/retro/eiffel/"
       - title: "⌨️ Eiffel Pico USB"
         summary: "The modern USB-based Eiffel successor, bringing USB keyboard, mouse and joysticks to the Mega ST. Configured, not yet installed."
         href: "/retro/eiffel-pico/"
+      - title: "🖱️ mouSTer"
+        summary: "Connecting a modern USB mouse to the Mega ST 4 'Low' with the mouSTer DB-9 adapter."
+        href: "/retro/mouster/"
+      - title: "🖱️ Laser Mouse"
+        summary: "Converting an original Atari STM-1 mouse to a modern laser sensor with the Atari mouse laser board."
+        href: "/retro/laser-mouse/"
+      - title: "📺 Atari to VGA"
+        summary: "Getting the Mega ST onto modern VGA monitors with three RGB-to-VGA adapters: MCSWITCH, a self-build and an ST2VGA Enhanced."
+        href: "/retro/atari-vga/"
+      - title: "📺 Monitor Compatibility"
+        summary: "The 15kHz problem explained, and which modern monitor panels actually cooperate with Atari colour modes."
+        href: "/retro/atari-monitor-compatibility/"
+      - title: "⚡ ET4000 in the Mega ST"
+        summary: "Adding higher resolutions to the Mega ST 4 'High' via a STGA adapter and an ET4000 card, and what it took to get it working."
+        href: "/retro/et4000-experiment/"
+      - title: "🔌 STPSU"
+        summary: "Replacing the aging Mega ST 4 'High' power supply with a modern STPSU for clean, stable power, especially for the ET4000."
+        href: "/retro/stpsu/"
+      - title: "🌐 NetUSBee"
+        summary: "Real internet via STinG and a USB port for FAT16 data exchange with Windows on the Mega ST 4 'High'."
+        href: "/retro/netusb/"
+      - title: "🔌 Wi-Fi Modem & BBS"
+        summary: "Dialing into telnet bulletin board systems from the Mega ST 4 'Low' using dhansel's WifiModem and terminal software."
+        href: "/retro/atari-networking-bbs/"
   - heading: "Amiga Corner"
     cards:
       - title: "⚔️ Vampire, A600GS or MiSTer"

retro/laser-mouse/index.njk

@@ -0,0 +1,39 @@
+---
+title: "Laser Mouse: Upgrading an Original Atari STM-1 Mouse"
+section: "retro"
+tags: "retro"
+description: "Converting an original Atari STM-1 mouse to a modern laser sensor with the Atari mouse laser board."
+layout: base.njk
+parent: "/retro/"
+---
+<h1>Laser Mouse: Upgrading an Original Atari STM-1 Mouse</h1>
+<div class="detail-content">
+
+<p>I converted an original Atari STM-1 mouse into a laser mouse using the Atari mouse laser board. It keeps the original Atari mouse shell and feel, but replaces the old mechanical/optical innards with a modern laser sensor, so the mouse actually tracks well again. It isn't currently in use on any machine, so it sits among my unused extensions for now.</p>
+
+<h2>The Atari mouse laser board</h2>
+<p>The board is a drop-in upgrade for an original Atari mouse. Instead of the worn-out original mechanism, it uses a laser sensor for smooth, accurate tracking while keeping the classic Atari mouse look. The board is sold by Tim (Lavago) and is available by email order.</p>
+
+<h2>Current version</h2>
+<p>There's a revised version of the board with several updates:</p>
+<ul>
+<li>Green PCB colour.</li>
+<li>A status LED on the board, which can be disabled with a jumper.</li>
+<li>Optimised firmware for even smoother movement.</li>
+<li>New optimised button adapters.</li>
+<li>Improved quality of the covers.</li>
+</ul>
+<p>It's available for Atari forum users by email order for 42 Euro including a 1040ST keychain (not 3D printed). When ordering by email, mention the keyword "Forum" and your address. Email: <a href="mailto:Info@Lavago.de">Info@Lavago.de</a>.</p>
+
+<h2>Why do it</h2>
+<p>The original STM-1 mouse is a classic, but the original sensors are getting tired after decades, and the feel isn't great compared to modern pointing devices. The laser board keeps the authentic Atari mouse shell while making it genuinely usable again, which is a nice middle ground between the original mouse and something like the <a href="/retro/mouster/">mouSTer</a> with a modern USB mouse.</p>
+
+<h2>Gallery</h2>
+<img src="lasermouse.jpg" alt="The converted Atari STM-1 laser mouse" width="640" height="853">
+<p class="caption">The original Atari STM-1 mouse converted to a laser sensor.</p>
+
+<h2>Sources</h2>
+<ul>
+<li>Atari mouse laser board - available by email from Tim (Lavago): <a href="mailto:Info@Lavago.de">Info@Lavago.de</a></li>
+</ul>
+</div>

retro/mega-st-heirloom/index.njk

@@ -0,0 +1,31 @@
+---
+title: "The Heirloom Mega ST 4: A Reference Machine"
+section: "retro"
+tags: "retro"
+description: "My father's original Mega ST 4, deliberately kept in factory-original condition as a baseline reference."
+layout: base.njk
+parent: "/retro/"
+---
+<h1>The Heirloom Mega ST 4: A Reference Machine</h1>
+<div class="detail-content">
+
+<p>This is my father's original Mega ST 4, deliberately kept in its historical, unmodified condition. It's the one machine in the fleet that stays true to how it left the factory.</p>
+
+<h2>Current State</h2>
+<ul>
+<li>Original TOS 1.04 reinstalled (onboard ROM, no external TOS switcher).</li>
+<li>No modern expansions active, no MonSTerBoard, no Cloudy/Storm.</li>
+<li>A classic floppy drive instead of a Gotek or emulator.</li>
+<li>Its own original Atari keyboard and mouse.</li>
+</ul>
+
+<h2>Role in the Fleet</h2>
+<p>This machine serves as a nostalgia and comparison reference. When problems occur on one of the modified Megas, I can test against this unchanged original state to distinguish bus, flash, or configuration errors from genuine hardware faults. It can also be used as a test platform for uncritical experiments, but stays as close to original as possible for nostalgic reasons.</p>
+
+<h2>History</h2>
+<p>The machine spent many years at my parents' house and was fully rebuilt and brought back into operation by me after I got seriously back into retro computing in 2020.</p>
+
+<h2>Plans</h2>
+<p>The plan is to use this machine again the way it originally was: hooked up to the old SM124 black-and-white monitor, and with the two old MegaFile hard disks (a MegaFile 60 and a MegaFile 30) connected, keeping the whole setup period-correct. Both are still stored in the basement at my parents' place for now.</p>
+
+</div>

retro/mega-st-high/index.njk

@@ -0,0 +1,56 @@
+---
+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 and a modern STPSU, 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>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. It 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">
+<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">
+<p class="caption">Inside the "High" machine.</p>
+<img src="high-3.jpg" alt="Mega ST 4 High detail" width="640" height="640">
+<p class="caption">A detail of the "High" setup.</p>
+<img src="high-4.jpg" alt="Mega ST 4 High expansion" width="640" height="640">
+<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">
+<p class="caption">Close-up of the "High" machine.</p>
+<img src="high-6.jpg" alt="Mega ST 4 High running" width="640" height="640">
+<p class="caption">The "High" machine in operation.</p>
+<img src="high-7.jpg" alt="Mega ST 4 High setup" width="640" height="640">
+<p class="caption">The "High" workstation setup.</p>
+<img src="high-8.jpg" alt="Mega ST 4 High board" width="640" height="640">
+<p class="caption">Board detail of the "High" machine.</p>
+<img src="high-9.jpg" alt="Mega ST 4 High final" width="640" height="640">
+<p class="caption">The finished "High" machine.</p>
+
+</div>

retro/mega-st-low/index.njk

@@ -0,0 +1,29 @@
+---
+title: "Mega ST 4 Low: Demo and Games Machine"
+section: "retro"
+tags: "retro"
+description: "The bargain-bin Mega ST 4 rebuilt as a LowRes demo and games machine, with Cloudy/Storm ST, Gotek, UltraSatan, SidecarTridge and a Wi-Fi modem."
+layout: base.njk
+parent: "/retro/"
+---
+<h1>Mega ST 4 Low: Demo and Games Machine</h1>
+<div class="detail-content">
+
+<p>Bought via eBay as a bargain, this Mega ST 4 is today my LowRes demo and gaming machine. It's the most heavily expanded of the fleet, but tuned for fast disk-image swapping rather than productivity.</p>
+
+<h2>History and Repair</h2>
+<p>I had originally cut out the TOS ROMs to experiment with external solutions, and afterwards it was unclear whether the board had been damaged in the process. Moving the <a href="/retro/storm-cloudy/">Cloudy/Storm ST combo</a> to this machine via the MegaBus connector brought it back to stable operation. The actual problem turned out to be a poorly and incompletely soldered CPU socket.</p>
+
+<h2>Hardware Configuration</h2>
+<ul>
+<li><strong>CPU</strong>, 68000 with socket, plus the <a href="/retro/storm-cloudy/">Cloudy/Storm ST combo</a> via the MegaBus adapter.</li>
+<li><strong>TOS/Flash</strong>, Cloudy as the TOS switcher/flash solution with EmuTOS and PP's improved iTOS 1.04, plus KAOS TOS installed as well (though rarely used).</li>
+<li><strong>RAM</strong>, 4 MB onboard ST-RAM plus 8 MB AltRAM via the Storm ST.</li>
+<li><strong>Mass storage</strong>, a <a href="/retro/gotek/">Gotek floppy emulator</a> in a 3D-printed case and an <a href="/retro/ultrasatan/">UltraSatan</a> ACSI-SD emulator.</li>
+<li><strong>Peripherals</strong>, a <a href="/retro/sidecartridge/">SidecarTridge Multi-device</a> on the ROM port, a <a href="/retro/atari-networking-bbs/">Wi-Fi modem</a> for dialing into BBSs, an original Atari keyboard with a <a href="/retro/mouster/">mouSTer</a> and USB mouse, and an <a href="/retro/atari-vga/">MCSWITCH</a> adapter for VGA output.</li>
+</ul>
+
+<h2>Role</h2>
+<p>Focused on LowRes demos and games, with convenient image handling via the Gotek and SidecarTridge. No need for complex productivity software or precise keyboard layouts here.</p>
+
+</div>

retro/mega-st2/index.njk

@@ -0,0 +1,32 @@
+---
+title: "The Mega ST 2: Spare and Test Machine"
+section: "retro"
+tags: "retro"
+description: "The Mega ST 2 that serves as an inactive backup machine for the rest of the Atari fleet."
+layout: base.njk
+parent: "/retro/"
+---
+<h1>The Mega ST 2: Spare and Test Machine</h1>
+<div class="detail-content">
+
+<p>The Mega ST 2 was given to me a while ago. Its role is purely as a backup: it sits inactive and is only meant to be brought back to life if the "High" or "Low" machine ever fails, not as an actively used machine.</p>
+
+<h2>Current State</h2>
+<p>It runs on original TOS with the internal RAM configuration, without the separate 4 MB expansion, which was removed for testing purposes and now sits set aside.</p>
+
+<h2>History</h2>
+<p>Everything in this machine was moved over to the <a href="/retro/mega-st-high/">Mega ST 4 "High"</a> that I was given, including its original power supply. It's not really a parts donor though, it's simply the spare machine now that the new Mega 4 carries the main setup. Back then it had an intermittent fault: after being on for a long time it would eventually show a white screen on boot. I first suspected the 4 MB expansion and removed it, but the fault persisted. Only after reverting it to the old TOS and a fully original state did it run stably again.</p>
+
+<h2>Ideas for This Machine</h2>
+<p>A few possible directions for the Mega ST 2, none of them decided yet:</p>
+<ul>
+<li>Reinstalling the 4 MB expansion, which was only removed for testing and is currently sitting set aside.</li>
+<li>An external <a href="/retro/gotek/">Gotek floppy emulator</a>, since an external unit would suit this machine well.</li>
+<li>An <a href="/retro/eiffel-pico/">Eiffel Pico USB</a> adapter for a USB keyboard and mouse.</li>
+<li>The <a href="/retro/acsi2stm/">ACSI2STM</a> as an ACSI hard disk option.</li>
+<li>A stereo sound mod.</li>
+<li>Playing MIDI Maze against the <a href="/retro/mega-st-low/">Mega ST 4 "Low"</a>: connect the two machines over MIDI, put the Mega ST 2 on the old MCSWITCH VGA adapter and the NEC monitor, and play together.</li>
+<li>The old Revision 0 <a href="/retro/sidecartridge/">SidecarTridge</a> could move here once the new Revision 3 is installed in the "Low" machine.</li>
+</ul>
+
+</div>

retro/monsterboard/index.njk

@@ -38,8 +38,27 @@ parent: "/retro/"
 <h2>Software</h2>
 <p>Alan provides three programs for the MonSTerBoard: M_FLASH.ZIP to write the onboard flash, M_ALTRAM.ZIP to configure the RAM (2, 4, 6 or 8 MB, then placed in the auto-start folder), and M_RTC.ZIP for the Dallas RTC module. In total you can install four TOS versions: two 192 KB and two 256 KB images.</p>
 
+<h2>TOS selection via the jumpers</h2>
+<p>The TOSSEL and FLASHSW jumpers pick which TOS the machine boots from the flash. A common setup maps them like this:</p>
+<table>
+<tr><th>TOSSEL</th><th>FLASHSW</th><th>Boots</th></tr>
+<tr><td>off</td><td>off</td><td>EmuTOS</td></tr>
+<tr><td>on</td><td>off</td><td>PP's modified TOS 1.04</td></tr>
+<tr><td>off</td><td>on</td><td>TOS 2.06</td></tr>
+<tr><td>on</td><td>on</td><td>Kaos TOS 1.4.3</td></tr>
+</table>
+<p>The MonSTerBoard is generally blitter-agnostic and works with all common Mega ST blitter variants, as long as the bus signals are clean. Common symptoms like a white screen with no boot are, in practice, usually caused by contact issues at sockets or incorrect jumper settings, not a defective blitter.</p>
+
 <h2>My Setup</h2>
-<p>In my Mega ST 4 "High" machine the MonSTerBoard provides the 8 MB of TT-RAM that TOS 2.06 and Geneva use for real multitasking. For storage I use the dual IDE interface, with a CompactFlash card attached and booting the system directly from it. There's no ACSI hard drive connected in this machine; the IDE boot is noticeably faster than an ACSI drive would be. Combined with the <a href="/retro/et4000-experiment/">ET4000 graphics card</a> and its dedicated monitor, it's the most capable machine in the fleet.</p>
+<p>In my Mega ST 4 "High" machine the MonSTerBoard provides the 8 MB of TT-RAM that TOS 2.06 and Geneva use for real multitasking. For storage I use the dual IDE interface, booting the system directly from a CompactFlash card. I started with a 4 GB card, but that didn't work reliably, so I switched to a 1 GB card, which works fine. There's no ACSI hard drive connected in this machine; the IDE boot is noticeably faster than an ACSI drive would be. Combined with the <a href="/retro/et4000-experiment/">ET4000 graphics card</a> and its dedicated monitor, it's the most capable machine in the fleet.</p>
+
+<h2>Gallery</h2>
+<img src="monster-ide.jpg" alt="MonSTerBoard IDE adapter with CompactFlash card" width="640" height="480">
+<p class="caption">The MonSTerBoard IDE adapter with a CompactFlash card attached.</p>
+<img src="monster-1gb.jpg" alt="MonSTerBoard with the 1 GB CompactFlash card" width="640" height="480">
+<p class="caption">After the 4 GB card didn't work, I switched to a 1 GB CompactFlash card.</p>
+<img src="monster-pins.jpg" alt="MonSTerBoard pins and jumper block" width="640" height="480">
+<p class="caption">The MonSTerBoard pins and jumper block.</p>
 
 <h2>Sources</h2>
 <ul>

retro/mouster/index.njk

@@ -0,0 +1,34 @@
+---
+title: "mouSTer: USB Mouse to Atari Adapter"
+section: "retro"
+tags: "retro"
+description: "Using the mouSTer adapter to connect a modern USB mouse to the Atari Mega ST 4 'Low' via the DB-9 port."
+layout: base.njk
+parent: "/retro/"
+---
+<h1>mouSTer: USB Mouse to Atari Adapter</h1>
+<div class="detail-content">
+
+<p>My <a href="/retro/atari-mega-st-fleet/">Mega ST 4 "Low"</a> machine uses a mouSTer, a universal USB HID to DB-9 adapter that lets me connect a modern USB mouse to the Atari. The original Atari mouse isn't in use here, instead the mouSTer gives the machine a far more comfortable USB mouse.</p>
+
+<h2>What the mouSTer is</h2>
+<p>mouSTer is the first fully configurable USB adapter for old computers, created by willyvmm. It plugs into the DB-9 mouse/joystick port of an Atari ST (and many other old computers) and lets you use a modern USB mouse. It's open source, with firmware updates done easily via a USB memory stick.</p>
+
+<h2>What it can do</h2>
+<ul>
+<li><strong>Atari mouse emulation</strong>, so a USB mouse behaves like the original Atari mouse.</li>
+<li><strong>Full configuration</strong>, adjustable mouse speed, full button mapping, and configurable autofire on any button.</li>
+<li><strong>Wide USB support</strong>, it works with essentially all USB mice and gamepads.</li>
+<li><strong>Easy firmware updates</strong> via USB memory.</li>
+</ul>
+
+<h2>My Setup</h2>
+<p>On the Mega ST 4 "Low" machine the mouSTer connects a USB mouse to the DB-9 port, giving a much better feel than the original Atari mouse. It works alongside the <a href="/retro/storm-cloudy/">Cloudy/Storm ST combo</a>, the <a href="/retro/gotek/">Gotek</a>, the <a href="/retro/ultrasatan/">UltraSatan</a>, the <a href="/retro/sidecartridge/">SidecarTridge</a> and the <a href="/retro/atari-networking-bbs/">Wi-Fi modem</a>. The original Atari keyboard is still used on this machine.</p>
+
+<p class="note">Worth a warning: before settling on the mouSTer I tested the <a href="https://polyplay.xyz/PS-2-Mausadapter-Atari-ST" target="_blank">PS/2 mouse adapter from Polyplay</a>, but it simply didn't work. I wrote to the shop several times and they even sent a second unit, but that one failed too. The shop still sells it, and despite asking the operator several times whether they had ever tested it themselves, I got no answer. If you're tempted, I'd test before you commit, or just go straight for a mouSTer.</p>
+
+<h2>Sources</h2>
+<ul>
+<li><a href="https://github.com/willyvmm/mouSTer" target="_blank">mouSTer - GitHub (project page)</a></li>
+</ul>
+</div>

retro/stpsu/index.njk

@@ -0,0 +1,47 @@
+---
+title: "STPSU: Modern Replacement Power Supply for the Mega ST"
+section: "retro"
+tags: "retro"
+description: "Replacing the aging Mega ST power supply with a modern CenturionTech STPSU for stable, clean power, especially for the ET4000."
+layout: base.njk
+parent: "/retro/"
+---
+<h1>STPSU: Modern Replacement Power Supply for the Mega ST</h1>
+<div class="detail-content">
+
+<p>My <a href="/retro/atari-mega-st-fleet/">Mega ST 4 "High"</a> machine runs on a modern replacement power supply, the <a href="https://centuriontech.eu/product/stpsu-st/" target="_blank">STPSU</a> from CenturionTech. I went for this because the original PSU is aging, and a modern supply delivers far more stable power, which matters especially with the <a href="/retro/et4000-experiment/">ET4000</a> graphics card drawing from the 5V and 12V rails.</p>
+
+<h2>Why a new power supply</h2>
+<p>The original Atari PSUs are decades old now, and their output rails can drift, ripple or sag under load. A highly upgraded machine like the "High" with its MonSTerBoard, IDE storage and ET4000 card draws more current than a stock ST, and a clean, stable supply avoids the crashes and instability that can come from a worn-out PSU. The STPSU is a drop-in replacement designed specifically for the Atari 520/1040 STF/STFM/E and Mega ST machines.</p>
+
+<h2>STPSU features</h2>
+<ul>
+<li><strong>True plug-and-play</strong>, a complete drop-in replacement, no modification to the computer needed.</li>
+<li><strong>230V and 110V AC</strong>, works on both power networks.</li>
+<li><strong>Efficient switched-mode design</strong>, very low heat dissipation.</li>
+<li><strong>High current output</strong>, supports heavily upgraded and modified configurations.</li>
+<li><strong>Stable, low-noise output</strong>, in all working conditions.</li>
+<li><strong>Zero noise design</strong>, no heatsink or fan needed.</li>
+<li><strong>Extra on-board output connector</strong>, to power additional devices.</li>
+<li><strong>On-board LED indicators</strong>, for operational status.</li>
+<li><strong>Safety features</strong>, thermal shutdown, short-circuit and over-current protection.</li>
+</ul>
+
+<h2>My Setup</h2>
+<p>In the Mega ST 4 "High" machine the STPSU provides clean, stable power to the <a href="/retro/monsterboard/">MonSTerBoard</a>, IDE storage, the <a href="/retro/et4000-experiment/">ET4000</a> and the rest of the workstation, keeping everything running reliably.</p>
+
+<h2>Gallery</h2>
+<img src="stpsu-installed-1.jpg" alt="The STPSU installed in the Mega ST" width="480" height="640">
+<p class="caption">The STPSU installed in my Mega ST 4 "High" machine.</p>
+<img src="stpsu-installed-2.jpg" alt="STPSU installation detail" width="640" height="480">
+<p class="caption">A closer look at the installed STPSU.</p>
+
+<h2>Manual and documentation</h2>
+<p>CenturionTech provide a <a href="https://centuriontech.eu/download/STPSU%20User%20manual%201.01.pdf" target="_blank">user manual PDF</a>. Since such documents can disappear from the web, I've also kept a local copy of the manual (version 1.01) in this project:</p>
+<p><a href="STPSU-User-Manual-1.01.pdf" download>Download the STPSU User Manual (1.01) here</a></p>
+
+<h2>Sources</h2>
+<ul>
+<li><a href="https://centuriontech.eu/product/stpsu-st/" target="_blank">STPSU r2022 power supply unit - CenturionTech (product page)</a></li>
+</ul>
+</div>

retro/tos/index.njk

@@ -0,0 +1,70 @@
+---
+title: "TOS: The Atari ST Operating System Explained"
+section: "retro"
+tags: "retro"
+description: "A short explanation of TOS and GEM, the versions that matter today, and the multitasking add-ons Geneva and MiNT."
+layout: base.njk
+parent: "/retro/"
+---
+<h1>TOS: The Atari ST Operating System Explained</h1>
+<div class="detail-content">
+
+<p>TOS (The Operating System, sometimes called Tramiel Operating System) is the operating system that powers every Atari ST, STE, TT and Falcon computer.</p>
+
+<h2>What TOS actually is</h2>
+<p>TOS combines a compact kernel (GEMDOS, providing file and process handling similar to CP/M and MS-DOS) with GEM (Graphical Environment Manager), the graphical desktop and windowing system that gives the Atari ST its familiar look with icons, windows and drop-down menus.</p>
+
+<h2>TOS vs. GEM</h2>
+<p>TOS and GEM are often mentioned together, but they're two distinct layers. TOS is the whole operating system, and it has two main parts: GEMDOS, the low-level kernel handling files, disks and processes, and GEM, the graphical environment. GEM (Graphical Environment Manager) is the desktop and windowing layer itself, providing the icons, windows and drop-down menus, plus its application programming interface. So GEM is a component of TOS, not a separate system. Its origins go back to Digital Research's GEM for the PC, which Atari adapted for the ST.</p>
+
+<h2>The official Atari TOS versions</h2>
+<p>The official Atari TOS versions are proprietary and were developed over the years for successive hardware generations. The most important ones:</p>
+<table>
+<tr><th>Version</th><th>Year</th><th>Highlights and target hardware</th></tr>
+<tr><td>TOS 1.00 / 1.02</td><td>1985/86</td><td>The original versions for the first ST models (192 KB ROM), still with many bugs and simple file handling. TOS 1.02 added Blitter and clock support.</td></tr>
+<tr><td>TOS 1.04</td><td>1989</td><td>The legendary "Rainbow TOS" with massive bug fixes, an improved file selector, real file moving on the desktop, and a faster GEM.</td></tr>
+<tr><td>TOS 1.62</td><td>1991</td><td>Adapted to the new STe hardware (sound DMA, hardware scrolling), fixing bugs of the problematic TOS 1.6.</td></tr>
+<tr><td>TOS 2.06</td><td>1991</td><td>A big step (512 KB ROM) for Mega STE/STe: built-in hard disk boot, scrolling file windows, optimised design and extended keyboard mappings.</td></tr>
+<tr><td>TOS 3.06</td><td>1990</td><td>Developed specifically for the Motorola 68030-based Atari TT030 (uses TT-RAM and higher resolutions).</td></tr>
+<tr><td>TOS 4.04</td><td>1992</td><td>The last official Atari version, for the Falcon030 with True-Color graphics modes and DSP support.</td></tr>
+</table>
+
+<h2>EmuTOS: a modern replacement</h2>
+<p><a href="https://emutos.sourceforge.io/" target="_blank">EmuTOS</a> is a modern, free, open-source replacement operating system, in contrast to the proprietary official Atari TOS versions. It's a complete reimplementation that in many ways goes beyond what the original Atari ROMs can do:</p>
+<ul>
+<li><strong>Built-in hard disk driver</strong>, unlike the original TOS, which often needed external driver software in the AUTO folder, EmuTOS ships with universal drivers for ACSI, SCSI and IDE devices.</li>
+<li><strong>Built-in command interpreter (EmuCon)</strong>, the larger ROM variants include a command line for entering DOS-like text commands directly.</li>
+<li><strong>Wide language and keyboard support</strong>, EmuTOS supports noticeably more languages and keyboard layouts than most regionally limited original TOS ROMs.</li>
+<li><strong>Modern filesystem compatibility</strong>, optimised support for DOS-compatible FAT16 partitions, which makes data exchange with modern PCs very easy.</li>
+<li><strong>Flexibility and updates</strong>, it can be run on real hardware as a ROM replacement, from floppy, or even as a program from within a running original TOS, without having to burn the physical chips.</li>
+</ul>
+
+<h2>PP's improved iTOS 1.04</h2>
+<p>The versions of TOS 1.04 modified by Pera Putnik ("PPera") add deep, unofficial system extensions that were never part of the original Atari TOS. While the original TOS 1.04 mainly fixed bugs, PPeras version breaks through the old Atari ST's hardware limits. This is the TOS I use on the <a href="/retro/mega-st-low/">"Low"</a> machine. The main additions:</p>
+<ul>
+<li><strong>Built-in IDE and ACSI hard disk driver (autoboot)</strong>, normal TOS 1.04 can't boot directly from IDE drives or modern SD-card adapters without first loading a driver (like HDDRIVER) from floppy. PPeras version has universal hard disk drivers built directly into the TOS ROM, so the ST boots immediately and very fast from modern storage like an UltraSatan or IDE modification.</li>
+<li><strong>FAT32 support and huge partitions</strong>, the original TOS 1.04 only supports the old FAT16 filesystem and is limited to small partitions (roughly 16 to 32 MB per drive). With PPeras patches, TOS 1.04 handles much larger partitions, making data exchange with modern PCs via SD card very easy.</li>
+<li><strong>"Chimera" versions (TOS 1.04 with the TOS 2.06 desktop)</strong>, these combine the stable, highly compatible core of TOS 1.04 with the more modern desktop of TOS 2.06. You get the comfort of TOS 2.06 (better file windows, desktop shortcuts) while keeping the near-100% game compatibility of the old TOS 1.04.</li>
+<li><strong>RAM optimisation for games (Raw Image Access / RIA)</strong>, special code in the ROM can stream games directly from hard disk or SD card as an image, so even large 1 MB games run on machines that would otherwise have too little memory for hard disk loaders.</li>
+</ul>
+
+<h2>KAOS TOS</h2>
+<p>KAOS TOS is a comprehensive software patch for the Atari ST's TOS, developed from 1990 to fix bugs and boost performance. It's not a standalone operating system but a patch for the original Atari TOS, mainly based on TOS 1.02 and TOS 1.04. The developers corrected over 80 known programming errors in the original system. KAOS 1.2 was published in the c't magazine, while the later KAOS 1.4.2 was sold commercially.</p>
+<p>It ran noticeably faster, and although critics claimed this was only from disabling visual effects, re-enabling them disproved that. Since the Atari ST keeps its operating system in ROM, KAOS was often burned onto EPROM chips and physically installed in the machine. Most cleanly written applications ran without problems, with special helper patches for the few incompatible ones. Atari never officially licensed the project but tolerated it on the market. It was shaped by Andreas Kromke and Normen Kowalewski, among others, and became well known in the Atari community through coverage in the ST-Magazin.</p>
+<p>KAOS TOS is also installed on my <a href="/retro/mega-st-low/">"Low"</a> machine, though I rarely use it. Theoretically it's there and available if needed.</p>
+
+<h2>Adding multitasking: Geneva and MiNT</h2>
+<p>Plain Atari TOS is a single-tasking system: only one main program runs at a time. Two well-known add-ons change that.</p>
+<h3>Geneva</h3>
+<p>Geneva is a resource-friendly, self-contained multitasking environment for the Atari ST. It runs on top of normal TOS and replaces or extends GEM, letting several GEM programs and accessories run in parallel, even on older and weaker Atari models without a big performance hit. It needs little memory and stays very compatible with older software that was never written for multitasking, which is why I run it on the <a href="/retro/mega-st-high/">"High"</a> workstation.</p>
+<h3>MiNT</h3>
+<p>MiNT (originally "MiNT is Not TOS", later "MiNT is Now TOS") is a much more powerful, Unix-like replacement kernel. It swaps GEMDOS for a Unix-style memory and process management layer, and together with a graphical shell like XaAES or N.AES it enables true, modern multitasking, today usually known as FreeMiNT. The catch is that it often needs stronger hardware, ideally a processor with a memory-management unit (PMMU) such as the Motorola 68030 in the TT or Falcon, and tends to run slowly on a bare old ST. I haven't managed to get MiNT running reliably on any of my machines, which is exactly why the "High" machine uses Geneva instead.</p>
+
+<h2>Sources</h2>
+<ul>
+<li><a href="https://emutos.sourceforge.io/" target="_blank">EmuTOS - official project page</a></li>
+<li><a href="http://www.mbernstein.de/atari/system/kaos.htm" target="_blank">KAOS TOS - mbernstein.de</a></li>
+<li><a href="https://atari.8bitchip.info/tosimprgu.html" target="_blank">TOS improving (iTOS) - PP's Atari page</a></li>
+</ul>
+
+</div>