THIS is an interesting machine. It came to me in 2016 from a chap called Brian Ecclestone who was downsizing and wanted to give his machines to a good home. I quickly headed off to Staffordshire with an empty car because there were a few choice things to collect. This amazing machine is a Model A BBC Micro, but with a twist. Most Beebs have a PSU in the back (that explodes) but this one had a 3.5" floppy drive! I realised a while back that it had never graced these pages so here we are.

The vast majority of Beeb owners bought the official ADFS upgrade to let their machines use floppies, but Brian had other ideas. He installed an OPUS DDOS interface powered by the same floppy controller Acorn sold - the Western Digital WD1770 - that allowed an external 5.25" and 3.5" drive work with the machine. Using an old ICL twin floppy drive enclosure he fitted a Farnell PSU to one bay and left the 5.25" drive in the other. An umbilical cable then snaked to an external power connector on the Beeb which had been fitted in place of the Econet socket.

Also in the machine was an SRAM chip and another PROM that's coated in black epoxy, I suspect this is a RAMdisk as Opus DDOS gives me a drive R to use. The monster PSU had 4 RIFA smoke generators in so they were pulled and replacements fitted once I'd deciphered the perhaps strange choice of wiring colours for the various harnesses. The PSU is rock solid so it was straight back in the enclosure and wired in.

First powerup produced the welcoming 'booooo-BEEP' of a happy Beeb, and I saw the Opus DDOS welcome prompt for the first time. Now, I've never used DDOS before, but thankfully the manual is online and I quickly got to grips with the 5.25" drive that booted happily with the disk that was in it. Next up was working out how to hook up and then control the 3.5" drive in the back of the machine. A bit of cabling origami got things neat and tidy, and I discovered what one of the wires coming out of the bottom of the machine was for - 12V for the floppy motor. DDOS gives drives a CP/M type quality with double sided disks - sides 0 and 1 are kept separate, so the 5.25" drive is 0 and 2 while the 3.5" is 1 and 3. RAMdisk is R and it shows up as initialised but empty. Cool.

Commands are similar to Acorn's DFS and there's some utilities in ROM to help things move quickly. Unfortunately, while examining the box of 3.5" floppies that came with the machine the drive developed a fault on side 0. Thankfully I had an external Atari ST floppy (a Chinon FZ-354) and this worked perfectly with the added advantage of it not needing the 12V rail. I imaged all the disks successfully so could use a Gotek to play the various games present.

Lovely beast, thanks again Brian! Now onto the pics.