Samples of Motorola Inc’s latest complex instruction set processor, the 68040, are now being distributed to key customers, with general sampling scheduled for the end of the first quarter. Keen to dispel the impression that it has been losing its mid-range heartland Unix business to the increasingly high profile Intel 80386 and 80486 chips, Motorola assembled endorsements from 35 computer manufacturers intending to build systems around the 68040, including Apple Computer, Bull SA, Commodore International, Hewlett-Packard Co, Nixdorf Computer, Philips and Unisys Corp. Rated at 20 MIPS at the only available clock speed of 25MHz, the 68040 is claimed to be 24% faster than the Intel 80486 running at the same clock speed, based on analysis on a simulator, a large increase on the 50MHz 68030 which operates at 12 MIPS and faster than some RISC processors. For maths calculations, Motorola claims an average of 3.5 MFLOPS, peaking at 8 MFLOPS. Integer, floating point unit, two memory management units and separate 4Kb data and instruction caches are crammed onto the 1.2m transistor chip (that’s four times more than on the 68030), which will sell for $795 in sample quantities. It is manufactured in 0.8 micron HCMOS technology, and its five processing units can process an instruction every 1.3 clock cycles compared to 3.4 on the 68030. Several RISC features are used in the integer unit, including frequently used instructions and addressing modes optimised for single cycle execution. The floating point unit is an 80-bit part compatible with the 68882 maths co-processor, but five to 10 times faster on frequently used instructions, according to Motorola. It includes a dedicated 64 by 8 hardware multiplier. The memory management system contains two sepsrate units allowing memory to memory transfers and simultaneous instruction and operand translations. Motorola estimates that companies around the world have invested $4,000m in engineering man-hours in developing 32-bit software for the 68000 family. The 68040 will continue to use this existing software base, but there will be a new C compiler. First out with 68040-based systems will be single board computer manufacturers such as Tadpole Technology Plc in the UK, and Dressler AG in Germany, while Bull HN said it had designed its DPX/2 range to incorporate the 68040 as soon as it was available. The chip is expected to be available in quantity during the third quarter of this year; the company declined to indicate prices for volume purchases were but says the price curve is expected to be similar to that for the 68030.
