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STLabs, an ATARI 16/32 computers hardware lab!

This page concerns MSTIDEM, a hardware upgrade I designed
for the ATARI MEGA ST computer.


  • 512KB flash ROM allowing dual-TOS or cartridge operation. Here are the possibilities :
  1. 256K TOS 2.06 + 192K TOS 1.X
  2. 256K TOS 2.06 + 128K cartridge (where you can put 128K of your favourite software)
  3. 448K alternative OS (like Emutos for which an IDE driver needs to be written from scratch)
in any case, a 64K area is reserved for a BIOS-like bootloader
TOS 2.06 is necessary to enable the IDE function
  • ATA-IDE interface suitable for silent Compact flash cards as well as conventionnal harddisks, including 2.5" and 3.5" connectors and a 2.5" hard disk place holder.
  • memory upgrade (Alternate Fast-Ram at 8MHz) up to 16-4-1 = 11Mb on top of ST-RAM
  • USB-slave UART and 7 general purpose I/Os for hobbyists.
  • no cut in the MEGA ST mainboard, only a few additionnal wires to be soldered for clock and for IDE interruptions.

  • 2007/02 : 5 PCBs sent for fabrication

the hardware design is in final but not debugged
The programmation logic has not yet begun

- Flash bootloader interface for TOS/cartridge and alternate memory configuration (BIOS-like)
- user friendly in system flash programming software


February 2007

A prototype PCB was sent for fabrication in China, I am waiting for 5 cards back.


contact : stlabs