Return to the Telecommunications page.
The development of the microprocessor is directly related to the development of the transistor. William Shockley, of Transistor fame, started a company known as Shockley Research Laboratories in New Jersey. He later moved to California to start Fairchild Electronics. Later, in 1968, two top Fairchild Electronics executives formed their own company (with some investment help from IBM) known as Integrated Electronics; or Intel for short!
The first release of a microprocessor, also referred to as a MPU (Micro Processing Unit) or a CPU (Central Processing Unit), occured. This was the Intel 4004, a 4-bit unit suitable for use in some adding machines and calculators.
Release of the first 8-bit microprocessor; the Intel 8008, designed for use as a Datapoint CRT controller.
Intel introduced the 8-bit 8080 microprocessor with significant improvements over the 8008. Motorola develops the 6800 8-bit microprocessor. Later that year, a few people from Motorola's 6800 development team left Motorola to form MOS Technology.
Introduction of the first microcomputer; the MITS Altair was powered by the Intel 8080. Later that year, three top Intel employees left to form Zilog, a venture owned by Exxon. MOS Technology introduced the 6502 microprocessor, a chip very similar to Motorola's 6800. The MOS Technology's 6502 microprocessor was cheap, and found use by people such as Stephen Wozniak (Apple 1 and Apple 2 computers) and Steven Mayer (Atari VCS video game). Motorola's 6800 only enjoyed limited success in the Personal Computer (PC) market, with SS-50 bus computer systems made by Smoke Signal Broadcasting and SWTPC (Southwest Technical Products Corp).
Motorola sues MOS Technology. MOS Technology is bought by Commodore International. Intel introduced an improved version of the 8080, the 8085 microprocessor.
Zilog releases the Z-80 8-bit microprocessor. This was very similar (and compatible with) the Intel 8080, but offered many improvements. It was most widely used in the Tandy TRS-80 PC family.
Intel introduces the 8086 16-bit microprocessor. Motorola releases the 6809 hybrid microprocessor . The 6809 was a 16-bit processor, but had a data path of only 8 bits. The Motorola 6809 microprocessor found use in the Tandy Color Computer but not in many other microcomputer systems. However, the 6809 was widely used in the industry.
Later that year, Intel released the 8088 16-bit microprocessor. Like the Motorola 6809, this device processed data internally using 16 bits, but only had a data path that was 8-bits wide.
Zilog also introduced a 16-bit unit, the Z8000 microprocessor.
Motorola released its version of a 16-bit microprocessor late in 1979. Called the 68000, it was far superior to other 16-bit microprocessors and programmers loved the ease of debugging and the simple addressing of up to an incredible (for its time) 16 Megabytes of memory!
The 68000 was first deployed in UNIX-based computers in late 1981 and earlyu 1982, then found its way into Apple 2 microcomputer boards. Later, Apple deployed the Lisa and MacIntosh computers using the 68000.
The IBM PC was introduced in 1981, using the 16-bit Intel 8088 microprocessor. The 8088, as mentioned earlier, could process data in 16-bit chunks, but only had a 8-bit data path (bus). Trade-offs between performance and cost resulted in a design that almost immediately proved to be trouble for IBM.
Intel released the 80186 microprocessor was similar to that of the 16-bit 8086, but with significant improvements in hardware design and integration. Tandy launched the Model 2000 in 1983 based upon this microprocessor. These PCs would run faster than IBM, with IBM compatibility, and lower cost!
The design of the IBM PC resulted in many functions that were decentralized and incorporated as "plug-in" modules, such as video, memory, and I/O ports. This created a huge peripheral market and perhaps more importantly, an "open" understanding of the hardware and bus architecture. While most competitors utilized the 8088, there were some manufacturers that could provide significantly improved performance through the use of the Intel 8086 and 80186 microprocessors. Also, the more specialized manufacturing capabilities of "clone" manufacturets could result in more savings to the customer.
Intel introduced the 80286 microprocessor. While still a 16-bit unit, the 80286 could address 16 Megabytes of memory with its 24-bit address bus! It also offered a new mode of memory addressing, called protected mode. It would boot in the 8088/86 mode (called real mode), but could switch to protected mode if instructed to access the additional memory. However, its inability to rapidly switch from protected mode to real mode inhibited its ability to support multitasking Operating Systems such as Windows or OS/2.
National Cash Register (NCR) was among the first manufacturers to produce a 32-bit microprocessor. This microprocessor processed data in 32-bit chunks, but only had a 16-bit data bus.
Motorola joined the list of 32-bit microprocessor manufacturers with the release of the 68020, which could access 4 gigabytes of RAM. A first for microprocessors, the 68020 had a 256 byte cache for instructions.
Subsequent development by Motorola of the 68000 family provided the second generation 68030, with 256 byte instruction and data caches. The 68040 increased the cache sizes from 256 bytes to 4 Kilobytes each and also included an onboard math coprocessor and memory management circuitry. The newest member of the 68000 family, the 68060, is a superscaler design that has multiple instruction paths; instructions can be processed even before completion of the previous instruction.
Intel released the 80386 microprocessor in 1985, a 32-bit unit. This also took advantage of a scalar architecture, meaning that it offered multiple instruction pipelines and could start working on a new instruction before the last instruction was completed.
The 80386, like the 80286, boots up in real mode but offered efficient switching between real mode and protected mode. It could even support multiple real mode (virtual) sessions.
Intel takes a step backward in 1988. releasing the 80386SX microprocessor. This was basically the same as a 80386 but had a 16-bit data bus, versus the 32-bit data bus of the 80386. This resulted in lower costs, and increased use of the processor family.
In 1990, Intel released the 80386SL. This was virtually the same the the 80386SX, with a 16-bit data bus. However, the 80386SL incorporated power management features which allowed it to be more readily used for portable computer applications.
Intel also released the 80486 32-bit processor. This processor also contained an onboard static RAM cache that reduced memory access times. It also include an onboard Floating Point Processor (also known as a "math coprocessor"), an improvement over the 80386.
Intel also introduced an upgrade philosophy called Overdrive. This program was a microprocessor design structure that could allow increased internal clock rates (and thus, increased performance) without any impact upon bus clock compatability.
In 1991, Intel released a cheaper version of the 80486, called the 80486SX. Instead of halving the data bus (as in previous microprocessor versions), the Floating Point Processor was excluded from this variation of the microprocessor.
Also, Intel released the 80486DX/50, a 50 MHz version of the 80486 (which ran at 25 MHZ and 33 MHz).
Intel introduced cheaper versions of the 80486DX running at 50 and 66 MHz internally. Cost savings were achieved by running external bus operations at 1/2 the internal rate (25 MHz and 33 MHZ respectively. These microprocessors were called the 80486DX2/50 and the 80486DX2/66.
Also, a low power variant of the 80486 microprocessor was introduced. This microprocessor, called the 80486SL, incorporated power management functions and found its way into portable computer systems.
Motorola released the MPC601, or Power PC. This was a high performance, 64-bit processor. Designed for operation at very high clock rates, the system also supported a superscalar architecture capable of processing 3 instructions concurrently. The Power PC also was the first use of RISC (Reduced Instruction Set Computing) in personal computers. The development of the MPC601 also included IBM and Apple.
The Intel 80486DX2/40 was another Overdrive processor, designed for use in systems with 20 MHz bus structures.
Intel's 80486SX/SL and 80486DX/SL basically obsoleted the existing 80486SL microprocessor.
The 80486DX4 family introduced in 1994 are clock-tripled, Overdrive devices, designed to give a high performance boost for 25 MHz and 33 MHz systems.
The 80486DX4-75 is a clock-tripled version of the 25 MHz 80486DX. The 80486DX4-100 is a clock-tripled Overdrive version of the 33-MHz 80486DX microprocessor.
The Intel Pentium processor probably would've been called the 80586 had not Intel wanted to employ a name that was more easily trademarked. It retained the 32 bit address bus from the 80486, but doubles the data bus to 64 bits. It also employs a dual pipelined or superscalar architecture for concurrent processing of instructions.
| Home | History | Multiplex | Xmission | Networking | Switching | Modulation |
comphis.html, ©1998 All rights reserved
Tampa Bay Interactive, Inc.
Last Revised on: Monday, 25-Oct-2004 19:45:13 EDT