The SCSI interface takes its power from the Master power supply. The two power connectors which usually go to the pins in the top left-hand corner of the motherboard plug into the interface and a set of spade clips on the SCSI board replace the removed connectors.

The interface generates a replacement clock signal which is taken to Link 6 on the BBC Master motherboard by the yellow wire. This is because the motherboard clock isn't steady enough to allow the video mixing genlock inside the LV-ROM player to work.

The ribbon cable plugs into the connector at PL12 on the Master motherboard, just to the left of the left-most co-processor connector.

At PL12, you should find a blue connector with a white clip. When the white clip is removed, a connector similar to the ROM cartridge connector is revealed. The ribbon cable plugs into this and then the white clip can be replaced.

However, there appear to be at least three varieties of Master motherboard. The "Domesday" version has the correct connector but some Masters have a set of pins instead. There are also some machines without a connector or plug at PL12 at all. This may be confined to the Master 512 as this was what I found inside Station 201.

At the top of the SCSI interface is a 50-way connector. This is for the ribbon cable which goes to the LV-ROM player. There is a handy cut-out slot in the Master backplane on issue 2 machines for passing the ribbon cable through.

The SCSI interface has 8 integrated circuits, 5 resistors and 4 capacitors.

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