Names, or rather numbers, have now been applied for the planned PowerPC chips which, as reported (CI No 1,917), should be first available in limited quantity before the year end. According to Michael Slater, editor and publisher of Microprocessor Report in the US, the 601, to sample later this year for production by Motorola Inc next year, will be used in the first PowerPC Macs and other low-cost desktops. This chip implementation, to be available on the open market, is a derivative of an IBM Corp Rios design, Slater notes, which explains how it is that the chip will be out so soon. It is Slater’s opinion that the 601 will rate 40 SPECmarks, while the 620 chip implementation, for high-end workstations and servers, to be available in 1994, will rate 100 SPECmarks. This will be a full 64-bit implementation, superscalar so that it probably issues two to three instructions per cycle. The 603, for use in portable computers and the 604 for mainstream desktop applications, will be available in limited quantities in the second half of 1993. The Rios RISC has been cleaned up create the PowerPC, concentrating on just what’s important for the desktop market. It will be binary-compatible with the RS/6000 Power RISC, since no operating code has been changed. The RS/6000 has basically been revised with single-chip implementations in mind. Some instructions including 38 opcodes – have been deleted to make room for the 88100 Mbus input-output interface and more cache – and some new ones added, such as new multiply and divide instructions that use general registers for their result, single-precision floating point instructions and a convert-to-integer facility. Compatibility with the RS/6000 is ensured through trapping of unimplemented instructions. And 64-bit extensions have been added. The first Apple Computer Inc PowerPC systems are expected to sell for under $2,000, Slater notes – these will be true Macintosh systems running Macintosh applications. Included in the System 7 operating system for the PowerPC will be a full emulation for Apple 68000 binaries – this will be faster than MC68040-based Macs that cost about four times as much. Apple expects to have 70% of System 7 applications converted by early 1993, when the first machines should be ready in volume. Slater reckons Apple is the one company that will make PowerPC happen. He notes that IBM and Apple are collaborating on the PowerPC CPU, and not on systems: Apple boxes will run System 7, not Pink or any new operating system.
