CPU of the Day: FOCUS on 32-bits

1983 HP FOCUS Board set – Pre FPU. Top left: Memory. Top Right: I/O and CPU bottom center

The year is 1981, Intel is making the 8/16-bit 8086/8088, and Motorola has released the 16/32-bit 68000 processor to much fanfare.  Motorola marketed this as the first 32-bit processor, but while it supports 32-bit instructions/data it does so with a 16-bit ALU.  HP, always used the MC68000 in their 9000 Series 200 line of computers, providing rather good performance for 1981. But this was the 1980’s and HP wasn’t satisfied with good, they wanted more, they wanted to implement a full 32-bit computer on something less then the 5,000 IC’s typically used to implement one at that time.  This meant making a processor like nothing else before, something with more then the 68,000 transistors of the MC68000 or even the 134,000 transistors of the new i286 Intel had announced.  What HP made is simply remarkable, in 1981 they announced the HP 9000 Series 500 computers, powered by an all new fully 32-bit processor called the FOCUS.  FOCUS was made on HP’s high density NMOS-III process, a 1.5u process, and used 450,000 transistors.  Thats 450,000 transistors on a single 40.8mm² piece of 1.5u silicon in 1981, a smaller die than the Intel 286.

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