A variant to the BBC Model B was produced for the American market. American BBCs were quite different in a number of ways to the British Beeb. For a start, the circuit board was shielded by a "Faraday" cage - a solid metal frame which was secured over the top of the circuit board preventing access to the PCB unless the cage was removed. The Faraday cage was a requirement of the American authorities to prevent emissions.

The circuit board of the American BBC was completely different from the British version. The 8271 disc upgrade was provided as standard but all the chips on the whole PCB were soldered to the board unlike the UK machine where many of the main components were placed in holders. Unfortunately this feature of the American type made the 1770 upgrade impossible.

The screen refresh rate was modified to 60Hz for compatibility with American televisions and the dimensions of the screen modes were altered. The UHF modulator was a different device to the UK version, suitable for use in the USA. When intended for use in the United Kingdom, however, these features were restored to the standard BBC B implementation.

The operating system was modified although it was reported as OS1.20 by *FX0. On start-up, however, the machine would display "Acorn OS 32K".

I owned an American BBC B from 1991 for several years and it was my first-ever BBC. Sadly I disposed of the machine a number of years ago although I wish I still had it as I have very rarely seen or heard of the American Beeb since.

In the early to mid 1990s, the pages of such august publications as BBC Acorn User and the like were filled with adverts for brand new BBC Model Bs. These were the American versions which had been shipped back to Britain and converted back to domestic use. I wish I had bought half a dozen of them back then as they are like gold dust now!

Changes abound inside here as we can see! The sideways ROMs have been shifted up a fraction to allow access without removing the keyboard.

With the keyboard out of the way, we can see that the American BBC has disc, Econet and speech upgrades fitted as standard.

In the bottom right-hand corner is the legend, "223,000 ISS 1 (C) COPYRIGHT 1983" and the Acorn Computers legend is in the top left-hand corner.

The script underneath has been adapted for the American market and there is the addition of a silver bar near the expansion ports which I recall being an ABSOLUTE DAMN NUISANCE because it falls off every time you take the keyboard off and is IMPOSSIBLE TO GET BACK ON!!

Ah, that's where I saw "RF Out", although I thought I'd seen it on a UK version as well.

My sincerest thanks to Ken Hewson for providing the pictures of the US Beeb seen above.