SidecarTridge® 256KB Decoder for Mega ST

Add 256 KB TOS support to your Mega ST, solderless

The SidecarTridge 256KB Decoder lets an Atari Mega ST boot 256 KB TOS images, including STe and Mega STe builds, together with the SidecarTridge TOS Emulator you already have. It seats in the MEGABUS connector, with no changes to the motherboard.

Full product page: features, compatibility, installation and FAQ ↗

No TOS Emulator yet? Get the 256KB Decoder + TOS Emulator Combo.

Which version do I need?

Look at the connector for the decoder on your carrier board, the board in the ROM sockets:

• 6-pin flat-cable connector: order For REV 4.0.0 (6-pin flexible flat cable).
• 2x3 pin IDC header: order For REV from 2.1.0 to 4.0.0 (6-pin flat cable with IDC plugs). Check that the chip labelled MUX is fitted on the left of the connectors.

MUX chip missing, or neither connector? Read Upgrading an older Mega ST carrier board or contact us before ordering.

Good to know

• Loads TOS 1.00 to 1.04, KAOS, MagiC 6.30, TOS 2.06, SuperTOS 2.06, custom TOS 2.16 and EmuTOS, in 192 KB and 256 KB builds.
• Mega ST only, every motherboard. Works with the stock Blitter board. Other mods are out of scope: contact us first.
• In the package: the decoder board and the cable for your version.

Step by step in the hardware installation guide.