On Jul 15, 20:13, Tony Duell wrote: ones). Yes, I they do (mine has it, and it's shown on all the diagrams) and now you mention it, it sounds familiar. Or more accurately, I remember seeing soething about converting US machines back to UK spec (or UK-usable spec, at least). One Acorn dealer re-imported a lot of unsold US and German Beebs some years ago. For readers unfamiliar with the BBC family, the original machines were the Model A and Model B; the A lacking certain components present in the B to provide multiple-ROM support, printer port, user port, serial port, analogue port, 1MHz bus or Tube (2nd Processor) ports, and only having 16KB RAM instead of 32KB. However, upgrading was easy (and both official and unofficial kits were readily available) and there was no difference at all between a B and a fully-upgraded A. Both could be further extended with a disk interface, proprietary network interface, and various third-party addons. Then came the B+. This looked similar from the outside, but had a redesigned PCB with 64K of RAM, some of which was used to "shadow" the screen and OS workspace. There was a 64K upgrade for it, which made it a 128K machine (though you couldn't actually do much with the extra RAM except put BASIC and it's variable space in it). It also used a 1770 or 1772 disk controller rather than the 8271 in the B (though you could fit an 8271 to a B+ or a 1770 to a B). That was succeeded by the Master 128 -- externally as well as internally different. It had a numeric keypad added, used double density disks by default, had two ROM cartridge slots, more comprehensive MOS (machine operating system), several utility ROMs that would be extras for a B/B+ were built in, and it used a CMOS 65C02. It also used more custom chips :-( There were some coprocessor addons for the 128 and other members of the family launched shortly after it, like the Master Compact (a two-box solution) and the ill-fated Econet Terminal (terminal and network software only, no BASIC and no extra interfaces, didn't sell well and was quietly dropped). After that, in 1987, came the Archimedes range, based on the ARM processor. Initially the A310 with 1MB, which still had red function keys to denote its standing as a BBC Microcomputer, then the A440 (grey keys, not a BBC Micro). And after that, the A3000 and its successor the A3010, which were the last with BBC endorsement and once again were single-box systems (like an Apple ][ or Amiga 500, etc). There were many other models in the ARM-based range, ending with the RISC PC, but none were BBC Micros. Despite all this, when someone refers to "a Beeb" they usually mean a Model A or Model B, not a B+ or later. Acorn trivia: the plastic case of the A3000 was deemed not strong enough to support the weight of a multisync monitor, so a sheet-metal stand was devised. The front of it sat on the strong edges of the A3000 case, the rear was supported on a bent-over section. Because it clung to the case, and from the front looked like the outline of a Klingon warbird, it became known as "the klingon". -- Pete Peter Turnbull Network Manager University of York