From Software Futures, a sister publication.
Apple Computer Inc has been out on the road promoting its forthcoming Rhapsody operating system (OS) to interested developers and giving the first details since the company purchased the base technology with its acquisition of NeXT Software Inc in December last year. Apple is now prepared to be specific and – surprisingly – it has chosen to demonstrate Rhapsody running on an Intel-based Compaq box, rather than its own PowerPC-based hardware. The fact that development work for Rhapsody on Intel is farther along than for Rhapsody on PowerPC is a reflection of the platform priorities of NeXT, rather than Apple itself, the company insists. The choice of hardware is at least a confirmation of Apple’s claims that Rhapsody will allow developers to deploy their work in a number of environments. Apple representatives say that programs written for the new OS’s so-called ‘Yellow Box’ (an object-oriented environment based on NeXT’s OpenStep) will be deployable under five different systems: native versions of Rhapsody for Intel and for PowerPC processors; the forthcoming 8.0 release of the Macintosh OS; and also under Microsoft’s Windows 95 and NT operating systems. The most surprising item in the list is not Windows but the Macintosh. MacOS cannot support true multi-threading and so it is likely to display a noticeable lack of performance when running modern applications that are designed to spawn multiple threads of execution. Implementing threads as independent co-operating processes under the old-fashioned rules of MacOS will have a much higher processing overhead than separate threads under, say, Windows 95.
By Lem Bingley
A spokesperson admitted that Apple is still invesrtigating the implications of supporting multi-threaded applications under MacOS: Deployment of Rhapsody applications under Windows 95 and NT will be via an Apple-supplied library and run-time element. This will effectively deliver a Yellow Box emulation under Windows 95 or NT, although applications will display a Windows look and feel. The run-time code was apparently inherited as a work in progress from NeXT, and involves no collaboration with Microsoft. Rhapsody itself will arrive as two separate stand- alone operating systems – one for Intel processors and one for PowerPC. Apple has re-affirmed plans to deliver a preview premier release early in 1998 with a complete unified release toward the middle of next year. Releases for both PowerPC and Intel are currently scheduled to be delivered simultaneously. Only Rhapsody for PowerPC will feature the Blue Box – a MacOS back-compatibility environment allowing Mac users to keep their existing software when they upgrade. Leon Baranovsky – Apple evangelist for Rhapsody, the internet and Java admits that the Blue Box will eat up 12MB of RAM when machines run both Rhapsody and MacOS applications, but points out that both old and new applications will be able to fully exploit Rhapsody’s virtual memory system. (Prepare for an increased level of hard-disk thrashing if you plan to run Yellow and Blue Box applications simultaneously in the future.) Baranovsky adds that the Blue Box code – which will be a direct ‘port’ of MacOS code to the bare- bones of the Rhapsody OS – will maintain a clear division from Yellow-Box Rhapsody code. There is still no word on a version of Rhapsody for Apple’s popular PowerBook range of portable computers. Jeroen Schalk, OS Technology evangelist with Apple’s European Developer Relations admits that none of the Rhapsody versions yet announced will have the power-management facilities necessary for a battery-powered machine. Schalk adds that implementing Rhapsody’s virtual memory facilities will be difficult on a machine which is not able to power the hard-disk continuously (portables switch off the hard-disk whenever possible to prolong battery life). You don’t see many Unix-based portables, for the same reason, Schalk said.