Designer and innovator Consoles Unleashed followed up on the Master System RGB Encoder Switcher device by releasing a very early version of the SEGA Master System Quick Solder BIOS

Designer and innovator Consoles Unleashed recently announced a new development in retro gaming with the release of the very first version of the SEGA Master System Quick Solder BIOS .


This BIOS is designed to offer an advanced solution for SEGA Master System console enthusiasts who want to experience multi-BIOS operation without the need for complicated switches or complex setups.


The SEGA Master System Quick Solder BIOS can be soldered directly under the system’s original BIOS, allowing you to enable multiBIOS operation quickly and conveniently.

One of the main features of this BIOS is its ability to integrate switchless region and BIOS support mod kits, which allow you to easily enable the BIOS in different extended region modes.

Thanks to the combined use of the SEGA Master System Quick Solder BIOS and the switchless region & BIOS support mod kit, users can enjoy a seamless gaming experience.

However, it is important to note that the BIOS can also be installed using a traditional switch, although this option is considered less convenient and is recommended only in specific cases.


  • A SEGA Master System console with a 28-pin BIOS.
  • A region without a switch and a BIOS Support Mod Kit installed (for operation without a switch) or an SPDT (On-On) switch and 2 x 1 kilohm resistors (for operation with a switch).


  • Currently only supports piggybacking on a 28 pin BIOS. If possible, 32-pin BIOS support will be added. It should work with any Master System console with a 28 pin BIOS.


  • PCB thickness of 1mm or 0.8mm is fine.
  • PCBs with castellated holes are recommended. Thin circuit boards with half-cut vias without castellation generally do not break the copper plating, but cleaning the vias can be time consuming.

Future development

  • 32-pin BIOS support.

Download: Source code SEGA Master System Quick Solder BIOS