Mega ST 4 Low: Demo and Games Machine
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.
Details
Serial: A1 08 4011143 · Manufactured August 1990
History and Repair
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 Cloudy/Storm ST combo 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.
Hardware Configuration
- CPU, 68000 with socket, plus the Cloudy/Storm ST combo via the MegaBus adapter.
- TOS/Flash, Cloudy as the TOS switcher/flash solution with EmuTOS and PP's improved iTOS 1.04.
- RAM, 4 MB onboard ST-RAM plus 8 MB AltRAM via the Storm ST.
- Mass storage, a Gotek floppy emulator in a 3D-printed case and an UltraSatan ACSI-SD emulator.
- Peripherals, a SidecarTridge Multi-device on the ROM port, a Wi-Fi modem for dialing into BBSs, an original Atari keyboard with a mouSTer and USB mouse, and an MCSWITCH adapter for VGA output.
Booting
Switching between High Res and Low Res is done at the VGA adapter, not in software. The iTOS 1.04 boot options select which drive to boot from:
- High Res, switch to EmuTOS on the Cloudy, then set the VGA adapter to Mono. Let it boot through.
- Low Res, switch to iTOS 1.04i on the Cloudy, then set the VGA adapter to Color. At the boot prompt:
- 1 + Space, boot from
C:\BT\1, opens D: GAMES - 2 + Space, boot from
C:\BT\2, opens E: DEMOS - 3 + Space, boot from
C:\BT\3, opens F: Med-Res
Role
Focused on LowRes demos and games, with convenient image handling via the Gotek and SidecarTridge. The desktop environment is an original NeoDesk 3.0 installation from the 1990s, just as it was back then. No need for complex productivity software or precise keyboard layouts here. The entire SD card has been cloned to the MiSTery Core on the MIST as a backup and for easy data transfer between the real machine and the FPGA.