MCS-86 -- iAPX 86/88
MCS-86
The Intel 8086 family of products was originally known as the MCS-86 product family. It was later
renamed to the iAPX 86 family of products.
History
The iAPX 86 family of products was introduced June 8, 1978 and included the Intel 8086 microprocessor.
"Intel’s 8086 was a major advancement in 1978. The chip brought the x86 instruction set that’s still present
on x86-compatible chips today. The chip was 16-bit throughout with 29,000 transistors and 16-bit
registers, and a 16-bit data bus. The processor had a clock speed of 4 MHz. The 8086 included segmented
memory addressing. The chip also contained a 20-bit address bus providing it with 1 MB of memory space.
The largest benefit was the 8086 kept assembly language compatible to a certain extent with the previous
8080. "
"The 8086 was not chosen for the original PC because IBM wanted to keep costs down by going with an 8-
bit bus design. The 8086 was used in some PC clones and later on in early IBM PS/2 models, but was
never a popular choice for PCs. This is probably because by the time it started to be used, the 80286 was
introduced, offering much improved performance over the 8086. The 8086 is architecturally identical to
the 8088 aside from the wider data bus. "
The iAPX 88 family of products was introduced June 1979 and included the Intel 8088 microprocessor.
"The 8088 operating at 4.77 MHz was IBM’s choice for the microprocessor in its first Personal Computer,
the IBM PC model 5150 (August 1981). Compared to its predecessor, the 8086, the 8088 microprocessor
comes across as a backward step in chip design. The 8088 was identical to the 8086 in every way-16-bit
registers, 20 address lines, the same command set-except one. Its data bus was reduced to 8 bits, enabling
the 8088 to exploit readily available 8-bit support hardware but effectively halving the speed of memory
access. "
Intel iAPX 86/88 Family Products
Part |
Description |
Year |
Photo |
| 8086 | 16-bit Microprocessor | June 8 1978 |  |
| 8087 | Math Coprocessor | 1980 |  |
| 8088 | 8/16-bit Microprocessor | June 1979 | |
| 8089 | 8/16-bit I/O Processor | 1979 | |
| 8089A | 8/16-bit I/O Processor | 1984-85 | |
| 8259A | Programmable Interrupt Controller | 1979 | |
| 8282 | 8-bit Non-Inverting Latch with Output Buffer | 1978 | |
| 8283 | 8-bit Inverting Latch with Output Buffer | 1978 | |
| 8284 | Clock Generator and Driver for iAPX 86/88 Processors | 1978 | |
| 8284A | Clock Generator and Driver for iAPX 86/88 Processors | 1980-81 | |
| 8286 | 8-bit Non-Inverting Bus Transceiver | 1978 | |
| 8287 | 8-bit Inverting Bus Transceiver | 1978 | |
| 8288 | Bipolar Bus Controller for iAPX 86/88 Processors | 1978 | |
| 8289 | Bus Arbiter iAPX 86/88 Processors | 1979 |