Progress and Pitfalls

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Progress and Pitfalls

YEAR	CHIP	INNOVATION	APPLICATIONS	PROBLEMS
1971	Intel 4004	First "computer-on-a-chip"	Arithmetic , i.e. Busicom calculator	Limited resources
1972	Intel 8008	8-bit bus width; first to implement interrupts	Dumb terminals, calculators, bottling machines	Interrupts worked poorly
1972	Texas Instruments TMS 1000	On-chip memory	Low-cost embedded applications	Programmers couldn't add external memory
1974	Intel 8080	10x performance of the 8008; separate address and data buses	Altair computer (first PC); traffic light controller	Difficult to program
1978	Intel 8086	16-bit bus width	Desktop and portable computing	Convoluted addressing scheme
1979	Motorola 68000	16-/32-bit chip powerful enough to handle advanced graphics	Apple Lisa ('83), Unix workstations, home videogame machines	Integer unit and ex-ternal data bus only 16 bits wide
1979	Intel 8088	16-bit internal architecture with 8-bit external bus	IBM PCs and clones	Same convoluted addressing scheme as the 8086
1982	Intel 80286	Added memory protection; 16 MB of addressable memory; 1GB of virtual memory	Standard PC CPU	Couldn't do page faults, lacked virtual memory
1985	Intel 386 DX	64 terabytes of virtual memory; 32-bit bus; 4-GB addressable memory	Desktop PCs	Didn't yet have an on-chip FPU or on-chip cache
1986	MIPS Computer Systems R2000	First motherboard-level RISC chip for workstations	Unix workstations; later, midrange computers	Difficult to program; incompatible with PC software
1987	Sun Microsystems SPARC	An open RISC architecture	Laptops to workstations to supercomputers	Required multiple chips due to pair of CMOS gate arrays and external FPUs
1989	Intel i486	First x86 with on-chip cache, FPU, and pipelined instructions	Desktop PCs, CAD	Lacked advanced techniques of some RISC chips
1989	Intel i960CA	First superscalar chip	Primarily embedded applications	Fairly expensive
1992	Digital Equipment Corp. Alpha 21064	200-MHz clock	Workstations and servers	Ran hot; expensive
1993	IBM and Motorola PowerPC 601	First out-of-order execution microprocessor	Apple Macintoshes, desktop PCs, servers	Programs not usually written for out-of-order execution
1993	Intel Pentium	Dynamic branch prediction; 64-bit external data bus and 32-bit address bus	Desktop PCs and network servers	Ran very hot
1995	Digital Equipment Corp. Alpha 21164	First to execute four instructions per cycle and the first with three on-chip caches	High-end desktop PCs, workstations, and servers	Runs hot; expensive
1995	Intel Pentium Pro	Has CPU chip and cache chip in same package	High-end desktop computers, graphics workstations, servers	Expensive