I thought the MDFS circuit board deserved a big picture. It is a view of the circuit board looking from the back of the MDFS towards the front.

In the top left-hand corner is the battery backup for and the CMOS RAM and real-time clock chip, the 146818, the same as used in the BBC Master 128.

In the bottom left-hand corner is the Econet interface which, unusually, does not use the 68B54 controller. I am not quite sure how it works. There are spaces for additional components and links which I would guess to be an optional clock generator. This would certainly have been a useful addition to the MDFS's capabilities.

The MDFS is Z80 based and the CPU is roughly in the middle of the board towards the right hand side. Just further along is the control ROM. Here is is version 1.05 which I think is the last issue. This is distinct from the disc-based software which stands at version 2.00.

Towards the middle in the bottom section is the floppy disc controller, a 9793 chip.

There will also be on-board RAM. I am not sure of the location but I imagine it is in the top right-hand corner of the board.