Sinclair ZX Interface 1 and ZX Microdrive (1983)

Sinclair ZX Interface 1 and ZX Microdrive

A few days ago I found a box in the warehouse of my friend Carlo, containing some Sinclair items. They had some traces of humidity, fortunately on the outside only. I took them apart, cleaned, tested and then reassembled them, taking a few pictures as usual.

Sinclair ZX Interface 1

Sinclair ZX Interface 1

The Interface 1 is composed of a single board, here’s the exploded view:

Sinclair ZX Interface 1 - Exploded view

The two sides of the board:

Sinclair ZX Interface 1 - Board

A detail of the connector:

Sinclair ZX Interface 1 - Detail

The ports on the back allow you to connect further expansions, create a computer network, and manage serial peripherals; the side connector is used to connect the first Microdrive.

Sinclair ZX Interface 1

Sinclair ZX Microdrive

Sinclair ZX Microdrive

Here’s the exploded view of the Microdrive:

Sinclair ZX Microdrive - Exploded view

This is the interior of the Microdrive shown from the other side, to see the two small boards better:

Sinclair ZX Microdrive - Boards

The microswitch checks if the cartridge is write protected: as for cassette tapes, you can remove a little plastic tab on the side to prevent writing. A detail of the head:

Sinclair ZX Microdrive - Head

The cartridges are really small, I took a picture with a one pound coin (it seemed more appropriate for an English product :-) to have a dimensional reference.

Sinclair ZX Microdrive - Cartridge

They are very delicate, and furthermore they weren’t built to last decades; in many of them the sponge material behind the tape just turns into dust, making them unusable.

Sinclair ZX Microdrive - Cartridge detail

Together with the Microdrive you got 4 cartridges in a case, instructions, stickers and a notepad.

Sinclair ZX Microdrive - Cartridges pack

Sinclair ZX Microdrive - Cartridges pack

The plate on the bottom can be unscrewed and repositioned to couple another drive (up to eight).

Sinclair ZX Microdrive - Bottom

And now a couple of pictures with the ZX Interface 1 and the ZX Microdrive connected to the ZX Spectrum.

Sinclair ZX Spectrum, ZX Interface 1 and ZX Microdrive

Sinclair ZX Spectrum, ZX Interface 1 and ZX Microdrive

Further reading

Infinite loop: the Sinclair ZX Microdrive story

Servicing the Sinclair ZX Microdrive

Replacement microdrive felt pad

One thought on “Sinclair ZX Interface 1 and ZX Microdrive (1983)

  1. Rich Mellor

    A really great article and plenty of high quality photos – the main problem with these has (for years) been the ULA overheating on the ZX Interface 1 (normally indicated by a small round melt spot on the top of the casing) and (as you say) the small felt pad on the microdrive cartridge disintegrating (or splitting) – they can go inside the tape mechanism itself and then jam the cartridge completely.

    Luckily – new felt pads are now available (although fitting them takes a lot of patience and a delicate touch) – – and last year, we managed to find a small stock of original ZX Interface 1 ULA chips –—LA15-312-3481


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