CRASH has received one of the first production +3s — the real thing, not a prototype — and while the micro business struggled with its doubts we put our Technical Editor on the case


THE NEW disk system, +3 DOS, should be fast enough for most purposes, though it’s a lot slower than third-party systems like Disciple and the Swift Disk. A 32K code file takes 21 seconds to SAVE and 18 to LOAD, less than a third of the Swift’s loading speed. Formatting is fast — it takes about 16 seconds to format one 173K side of a three-inch disk. The RAM disk of the original 128 is still present; the syntax to operate it has changed for the better, but the capacity has fallen from 74K to 48K.

Despite the extra disk drive and printer port, the +3 is simpler internally than the +2. There’s very little left of the original Spectrum design, apart from the minor bugs in the ROM. It seems they’ve all been carried over from the +2 (except the NMI bug, which sports a one-byte correction).

Both Sinclair logic arrays have been replaced by a single ‘flat pack’ chip, as used on the Amstrad PCW word processor. The 128K of memory has been squashed into four 64Kx4-bit chips. The nonstandard drive is identical to the unit in CPC and PCW Amstrads, and you can plug in a DMP-2000 printer or FD-1 second drive — both of which were originally made for the CPC range.

The +3 is Alan Sugar’s quick and dirty answer to the home market, and it kills the CPCs stone dead. +3DOS is a souped-up version of AMSDOS, but it hasn’t been linked into the Spectrum’s streams. That means you can’t use sequential or random-access file from ZX BASIC, even though there’s 4K of unused space in the DOS ROM.

The +3’s 64K ROM also holds a set of diagnostic hardware tests. You can get at these by pressing RESET and BREAK, to call up the 128’s TV setup display, and then pressing two groups of keys simultaneously: QAZ and PLM. You need a printer and special test disk to make the most of these routines, but they’re fun to play with and should help retailers sift out faulty machines.

I expect the +3 circuit board, less disk controller, will be used in future +2 machines to take advantage of the simplified logic circuitry. There’s already a connection-point for an internal cassette drive, which could take the place of the +3’s disk. A version with built-in tape and external disk drivers would also be practical.

+3 DOS works happily from cassette, but the machine doesn’t come with a tape lead — you need two mono jacks connected to a stereo one. Maybe this is Amstrad’s way of encouraging the release of new programs on disk, but there’s a vicious circle there.

The +3 doesn’t let you transfer the majority of games to disk from protected cassettes, yet software houses won’t supply games on disk till lots of machines have been sold.

Several firms hope to break the deadlock with ‘magic button’ copying add-ons, despite the lack of some Spectrum edge-connector signals which previous copiers have relied upon. Even then, there could be trouble copying programs which use the new CP/M 64K RAM configurations, as there’s no ROM space for a copying device to put its own code in.

The +3 circuit board will doubtless be redesigned soon, as there are three bodges on the back of the board. Two capacitors, three diodes and a resistor have been tacked on to coax the machine into reliable operation.

Several signals have vanished from the edge connector. The video and colour-difference lines have gone, though you can still hook up an RGB monitor through the Peritel socket, and a Composite one by clipping wires onto the circuit board, as explained in TECH TIPS Issue 28.

The nine-volt and five-volts supplies have gone, as have the ROMCS and IORQGE lines used by some add-ons. As the manual puts it, ‘there is no guarantee that a device which ran correctly on a Spectrum 48K will run on a +3.’

The +3 works; it’s well-documented and professionally-made. But other Spectrum disk systems offer better performance at a similar upgrade price.



THE friendly, homely high street is a tough place. In the micro business, some 15 chains are racing for your cash; none can afford to back a loser. And despite its Spectrum pedigree, the +3 is given only an outside chance.

Few high-street chains have followed Boots and decided to stock the +3. Sean Willis, who chooses computers for all W H Smith shops, is dubious about the +3’s prospects — there won’t be a high demand, he says. ‘It’s fairly specialised, possibly overpriced.’

Nearly all the big chains’ computer buyers agree £249 is too much for the +3. It’s too close to the price of machines like the Atari ST and Amiga, they believe, and shoppers with hundreds to spend will go for those.

But the micro industry is sure it’ll come down to £199 in the autumn, when Christmas present-buying is big business. Dropping below the £200 mark would bring the +3 within many more people’s spending range, and the increased sales could outbalance the lower price.

‘If the price came down to £199 I’d be more enthusiastic; if it came down to £150 I could move the +3 in quantity,’ says an independent retailer, Julian Musgrave of Games World in London.

Of course there’s no Spectrum without software, so shops and software houses are playing a waiting game — who’ll commit themselves to the +3 first?

Already two major houses, Activision and Ocean, are positive.

But Domark’s Mark Strachan speaks for the majority when he explains ‘we’ll sit on a fence for a while. If it sells well, we’ll probably convert some of our original games onto disk, but we won’t write for the + 3 specifically.’

Another problem: the three-inch disks are expensive, which may rule out single-game budget releases.

Still, if the new machine proves popular the software houses will be grinding out +3 games to feed the market. And Amstrad boss Alan Sugar reputedly expects to sell half a million +3s in the UK and Europe.

Says one high-street chain’s computer expert: ‘They’re a strong and aggressive company. And I’m sure if Alan has stated half a million they’ll go a long way toward achieving that.’