Acorn BBC A3000 - Serial Port upgrade

The Acorn BBC A3000 was not supplied with the relevant line driver and ACIA controller chip that supports the use of the 9-pin Serial port on the rear of the machine. By simply adding these two chips into the relevant sockets on the motherboard, you can add the serial comms capability that the connector promises.

The 65C51 ACIA and LT1133 chips fitted for the A3000 serial upgrade

Chip Availability

The line drivers are still manufactured (Jul. 2011) and are available from many suppliers including RS-Components. The line driver chip required is the LT1133ACNPBF.

The ACIA communications chip is a little harder to find these days although not impossible. Searching ebay for a 65C51 ACIA chip reveals a few available ranging in price from just over £4 (GBP) to just over £23 (GBP). As with all ebay purchases, it's buyer beware. Please do your homework before buying things from ebay.

Alternatively, you could check the specialist suppliers like RetroClinic and CJE Micros to see if they have a set of chips available for you.

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Acorn BBC A3000