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, the Mega ST 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.
+ +Mega STs were sold as Mega 2 (2 MB RAM) and Mega 4 (4 MB RAM), both 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.
+ +A side project involved connecting to the internet via a serial Wi-Fi adapter running czietz's firmware, communicating through Connect95. A self-built Linux proxy (WebOne) was meant to enable Telnet and HTTP access via the Cab browser. The Wi-Fi connection proved not to be consistently stable, and switching to Hatari on a Raspberry Pi 400 in VDI mode with a more stable network connection is recommended as an alternative.
+A few possible directions for the Mega ST 2, none of them decided yet:
+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.
+The TOSSEL and FLASHSW jumpers pick which TOS the machine boots from the flash. A common setup maps them like this:
+| TOSSEL | FLASHSW | Boots |
|---|---|---|
| off | off | EmuTOS |
| on | off | PP's modified TOS 1.04 |
| off | on | TOS 2.06 |
| on | on | Kaos TOS 1.4.3 |
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.
+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 ET4000 graphics card and its dedicated monitor, it's the most capable machine in the fleet.
diff --git a/retro/tos/index.njk b/retro/tos/index.njk new file mode 100644 index 0000000..941ab73 --- /dev/null +++ b/retro/tos/index.njk @@ -0,0 +1,23 @@ +--- +title: "TOS: The Atari ST Operating System Explained" +section: "retro" +tags: "retro" +description: "A short explanation of TOS, the operating system behind every Atari ST, and the versions that matter today." +layout: base.njk +parent: "/retro/" +--- +TOS (The Operating System, sometimes called Tramiel Operating System) is the operating system that powers every Atari ST, STE, TT and Falcon computer.
+ +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.
+ +TOS 1.00 shipped with the earliest STs, while later revisions like TOS 1.04 and TOS 1.62 added bug fixes and Blitter support. TOS 2.06, used on the Mega STE and commonly flashed onto expanded Mega STs today, added support for higher resolutions and better compatibility overall.
+ +Modern replacements and alternatives like EmuTOS (a free, open-source reimplementation) and Kaos TOS are frequently used on modified machines to fix compatibility issues, add features, or simply avoid depending on scarce original ROM chips. PP's improved iTOS 1.04 is another popular option, adding real FAT16 filesystem support for much better hard disk handling. These are exactly the kind of setups used across the machines documented on this site.
+ +