RetroClinic DualOS ROM board

The RetroClinic DualOS ROM board provides several features to the Acorn Master that are not normally available.

• The ability to switch between Acorn MOS 3.20 and 3.50
• Year 2000 fixes
• Built in support in ADFS for the RetroClinic DataCentre

The wires leading away from the DualOS board are connected to a switch that enables the selection of the different Acorn MOS releases whilst the Acorn BBC Master is powered off.

I located the switch on the underside of the Master keeping it safe and maintaining the original look of the machine when in day to day use.