MICROPROCESSOR HISTORY

• calculators (Busicom...computronic)
• prior use of ASICs, then 4004 introduced

4004, 4bit data; 8 or 12 bit addr (1971)
                 (256byte max prog. len)
      BCD instructions (1 digit at a time)
      accumulator
      program counter
      no interrupts
      no stack pointer
      4-bit wide data field and
      12-bit addr.?
      addr and data multiplexed on same 4-bit bus.
      for memory write, the device wrote three nibbles to get addr. (latched
      outside device), then the 4-bit data.
      (16 package pins welded on, expensive per pin)
      PL/I programming language
November of 1971, first microcomputer (Intel), MCS-4 system used 4004
microprocessor, 4001 ROM, 4002 RAM, and 4003 shift register.


world's first microprocessor operating system

8008 (1972,1973)
     8 bit data, (can express upper and lower case)
     12 bit address (4k program)
     accumulator
     index register 16 bits long
     stack pointer
     interrupts

1974: first commercial microcomputer, Scelbi 8-H, based on 8008

4040 some logical operations added to ALU.
internal stack of 12bit wide words,

8080 (1973,1974)     6800 (1974)     6502 (1975)
1975: Altair 8800

1975 Zilog Z-80 

1977-79 MC68000, Z8000, i8086 

1981: first portable computer: Osborne 1: optional battery,
two 5 1/4 floppy drives, built in 4" tv screen.

CP/M-based.

Compaq Deskpro 386 (1986) beat IBM to market with Intel 80386 microprocessor.

80486 (1989)