Macs and PCs use different formats for disks, but there are many ways of making them work together, writes Stephen Pritchard
The Apple Macintosh has always been slightly non-conformist. When IBM was as famous for its grey suits as its mainframes, Apple executives preferred more casual, Californian attire. When the computer industry embraced IBM's standard for a desktop PC, using Intel processors, Apple chose Motorola. When the personal computer market embraced Windows, Microsoft's graphical interface, the Mac kept faith with its own, proprietary system.

As a result, Macintosh users tend to be a fiercely loyal lot, ever ready to sing the praises of the Mac and deride the PC. But the most fervent Mac loyalist cannot deny that incompatibility with the ubiquitous PC and its ubiquitous software can be a nuisance. Even Apple now realises this, with "compatibility" its buzzword for 1995, and machines that will run PC programs plugged in the press and on prime-time television.

There are plenty of PC-Mac compatibility horror stories. At a regional newspaper, no one could copy a Macintosh file to the PC-based editorial system. Eventually, the article was laser-printed from a Mac, and scanned into a PC using optical character recognition software.

That was almost certainly unnecessary. Although Macs and PCs use different formats for disks, all current Macs (and almost all older ones) can read or write floppy disks in Dos format. By saving a file on to a (Dos) disk as a text-only Ascii file, you can reload it into a PC and work on it from there.

Many programs can translate the file back into a language they understand. For example, if you save a Mac Word file as "plain text", a WordPerfect file on a PC will decide it is WordPerfect 4.2 and happily use it.

This is fine if all you want to work with is text. But even a fairly basic word processor now supports multiple columns, coloured text, boxes, graphs and other fancy formatting. Recreating that from raw text in, say, a 30-page report would be more than time-consuming. Ideally, one machine should be able to read or "translate" the file and all its formatting from another.

Translation is easiest where Mac and PC versions of the same application are being used: the two versions of Microsoft Excel and Word, or Novell's WordPerfect for example, are almost identical.

Utilities are available to smooth the process, including Macintosh PC Exchange, which comes free with new Macs, MacLink, Dos Mounter and AccessPC. These allow PC discs to appear on the Mac desktop as if they were Mac disks and overcome the hassles of Apple File Exchange familiar to users of older Macs.

It is harder for PC users to read Mac files, as no such capability is included with Dos or Windows. The simplest way is to ask the Mac user to save the file on a PC disk, preferably in a format listed under the PC program's import options. The only other solution is Insignia Solutions' MacDisk. This PC program will read Macintosh floppies in either Dos or Windows, although it is limited to high-density disks.

So much for transferring files between the two types of computer. But what if you have a Mac and want to run software available only in PC form? Lotus's 1-2-3 and Novell's Quattro Pro spreadsheets, as well as Microsoft's Access database, are examples. There is also a better choice of accounting and finance packages for the PC than the Mac. Designers working mainly on a Mac are unlikely to buy a PC to do the books. What can they do to persuade their machines to run software written for PCs?

There are two solutions: they can try a software technique called emulation, or they can add extra hardware.

Emulation has become easier since Apple launched its Power Macintosh range last year. These machines contain PowerPC microprocessors using Risc (reduced instruction set chip) technology, which delivers greater speeds than conventional chips.

Some of the new Macs come with an emulator, SoftWindows, making use of the PowerPC's processing abilities. Developed by Insignia Solutions, Softwindows gives Power Macs reasonable PC performance with most software from the Macintosh desktop without any extra hardware, although 16Mb of Ram (main memory) is recommended. Many Power Macs come with only 8Mb; the extra chips will cost about £250.

The emulator runs Windows only in standard mode, which rules out heavyweight software such as WordPerfect 6 or CorelDraw. Nor does the package support Soundblaster, which makes it impossible to get the best out of some multimedia and games software.

Insignia is updating Softwindows for the third quarter of this year, solving both the processor and sound limitations. But for users needing more power, hardware solutions may be more appropriate.

Apple now has "Dos on a card" - as featured on television - for its Power Mac range. The card, currently available for the Power Macintosh 6100 and the new Performa 630 Dos Compatible, carries a full 486 processor and a slot for its own memory, which is vital for maximum performance. It can run PC applications in the background, and the user can switch back to the Mac by pressing a key.

The PowerPC chip is the product of an alliance between Motorola, IBM and Apple. They hope it will offer real competition to PCs with Intel chips and Windows. To achieve this, the partners are designing an "open" system, which any manufacturer can adopt.

Finally, you could overcome the compatibility problem by avoiding a PC or a Mac completely. If you buy a Unix-based workstation from Sun or Hewlett- Packard, you can buy a Mac emulator, called MAE, as well as Windows options. The workstations have the power to run both systems at once, though it does not come cheap: MAE is £375 and the hardware, say an entry-level Hewlett-Packard HP9000 712/60, would cost £3,500 plus VAT. For most of us a more practical option is still to stock up on floppy disks.

Useful numbers: Apple, 0800 127753; Computers Unlimited (Dos Mounter), 0181 200 8282; Insignia Solutions, 01494 459426; Principal Distribution (MacLink Pro), 0181-813 5656; Simms International (Reply cards), 0181- 213 5000; GraphicConvertor, e-mail