Intel 8088

  • Intel
  • AMD
  • NEC
  • Siemens AG
  • Mitsubishi

The Intel 8088 is a 1979 imagined 16 -bit microprocessor from Intel. From his already introduced in 1978 "big brother", the Intel 8086, it differs only by its only 8-bit wide external data bus and one of six reduced to four bytes of command queue (English prefetch queue).

The 8088 was the first scaled-down version of a CPU from Intel. She established a tradition of low-cost CPUs that runs on the 80188, the 80386SX and 80486SX to today's Celeron and Pentium dual -core processors in the x86 history. Also Motorola then offered a stripped-down to 8 bit variant of its successful 68000 CPU, the 68008th


The taking out of an 8 -bit wide data bus allowed the use of lower-cost 8 -bit components for the rest of the electronics of the machine, but at the expense of speed. For this reason, the 8088 was noticeably faster than the conventional 8- bit processors. Nevertheless - or perhaps because of it - he was selected by IBM as the CPU for the IBM PC. IBM wanted to advertise on the one hand with 16- bit technology, on the other hand make their own minicomputers no competition. In addition to that we developed parts of the electronics from one end of the 1970s, but was able to take unsuccessful computer called Datamaster on the market, the 8085 CPU had an 8-bit wide data bus. The decision for the IBM 8088 established the success of the x86 family, although the CPU was considered by many experts rather than underpowered and the whole architecture as little future. In addition to the NMOS version also has a CMOS version was offered as 80C88.


The 8088 can operate at a minimum and a maximum mode. The election is on the MN / MX pin 33 If he switched to 0 V (Low), operates the 8088 in maximum mode, at 5 V ( High) in minimum mode. At the minimum, mode compact simple circuits can be realized; the necessary control lines, the processor itself is available. The maximum mode is primarily intended for multiprocessor operation or for working with the 8087 math coprocessor. The necessary control lines are not provided, but generated by the bus controller 8288.

The 8088 has no internal oscillator. The required clock is generated externally from the oscillator chip 8284. Further, a latch is to separate the address from the multiplexed Adress-/Datenbus required, such as the 8282nd

Peripheral Devices

  • Intel 8282/8283 8- bit latch
  • Intel 8284: Clock
  • Intel 8286/8287: 8-bit bidirectional driver
  • Intel 8288: Bus Controller
  • Intel 8289: bus arbiter