This device facilitates the connection of a vintage BBC Microcomputer to a PC or any other computer with standard USB ports.
This gives the ability to transfer files direct from your PC to the BBC and vice versa, take control of the BBC from the PC (using suitable, freely downloadable software) and more.
This adapter comes with approximately 500mm cable terminated with a 5-pin "domino" DIN plug for the BBC end, and a mini-USB socket at the other end of the module to receive a standard USB cable from the PC.
The adapter works with the full range of speeds available on the RS423 port, including 19200 baud. Be aware, though, that Acorn did not guarantee 19200 baud transmission, so your particular machine may struggle at that speed.
Connection of the adapter is straight forward: simply insert the 5-pin DIN plug into the RS423 port of the BBC and connect the adapter to the PC using a standard USB to mini USB cable. Note that it is possible to insert the DIN plug in two orientations: the correct way is with the dimple in the shield facing towards the UHF and Video sockets. No harm will be done to either the adapter or the BBC Micro if the plug is inserted upside down – it will simply not work.
Connection to the USB port of your modern device is simply by means of a standard mini-USB to USB cable suitable for your machine.
This adapter can be mounted inside the BBC’s case. The cable is connected to the adapter with a small plug allowing it to be easily removed from the PCB, and separate solder terminal points to allow you to solder your own wires to connect directly to the BBC’s circuit board. The labelling next to the solder points indicate the data direction at the adapter, so the pad marked “Tx” should be wired to the BBC’s “Rx” terminal, and so on.
More information is contained in this PDF document.