Seymour Cray is not joking when he says that while Apple designs its computers on a Cray supercomputer, he is using nothing more than an Apple to design the Cray 3 and Cray 4. Actually he uses an IBM Personal these days, but his joke makes the point. What does Apple Computer use its Cray X-MP/48 supercomputer for? Microbytes Daily has been finding out, and reports that the machine – running under Unix rather than CTSS – is currently being used to develop visual interfaces for the Macintosh and future products. The Cray is part of a $20m installation used by Apple’s Advanced Technology group and consists of four CPUs operating at 9.5nS per cycle, 8m 64-bit words of program memory, and 8m words of input-output buffer memory.
Ultra frame buffer
The input-output system supports multiple 50Mbit-per-second channels – the Hyperchannel from Network Systems Corp, Minneapolis, and one high-speed channel operating at 850Mbits per second, which Cray calls the HSX channel. For storage, the system includes eight 1.25Gb drives for a total of 10Gb, as well as several tape back-up systems. The HSX channel is linked to a high-performance frame buffer system from a San Jose start-up firm named Ultra Corp. The Ultra frame buffer enables graphics images from the Cray to be displayed directly on a video display terminal. According to Sam Holland, manager of advanced technical projects, Apple is the first company that Cray has allowed to access the HSX channel. In fact, Apple claims to be the only company to use the Cray in an actual development environment. The Hyperchannel links the Cray to several nets of Apple Macintoshes via a VAX-11/785, a VAX-11/780, and a Sun/2. The Macs are linked to the VAXes and the Sun via AppleTalk in series with Ethernet. Ethernet and AppleTalk are bridged by a converter system from Kinetics Inc. Users log into the Cray from a Macintosh via a micro-mainframe package from Pacer Inc. Once logged in, the Macintosh performs as a remote terminal of the Cray. The Cray uses the Unicos operating system, which is Cray’s licensed version of Unix System V. In addition to the network, a Silicon Graphics system for high-speed animation is connected to the Cray via the Hyperchannel. Animation is primarily used to simulate high-speed video interface scenarios on the Macintosh and future machines. Apple anticipates that the system will soon include a VME board operating at 50 megabits per second, connecting a Mac II directly to the Cray and eventually it will have keyboards and mice connected directly. Another objective is to link Ethernet directly to the Cray, bypassing VAXes and Suns.
C or Smalltalk
At present, about 200 users have access to the Cray and only about 10 use the system at one time. The other area of Cray activity for Apple involves, for the most part, VLSI circuit design and simulation with most of the code written in C or Smalltalk. In addition to a much shorter development cycle, one of the main advantages of using the Cray as a simulation tool, Apple says, is that once created, designs can be edited and modified in an interactive, real-time environment. Although Apple has yet to release a product fully simulated and tested on the Cray system, the Mac II’s NuBus technology, which was engineered before the Cray went on line, was verified on the Cray before final release. The company adds that it may have some VLSI products out next year but speculates that it would probably be about two years before release of the first product that was engineered and simulated on the Cray from scratch. Although Apple believes that simulating products on the Cray means less development time, it can’t quantify the savings. It says that the main benefit of the simulation process is that once it has completed and verified the design of a product there will be no unforeseen problems.