1 CS402 PPP # 1 Computer Architecture Evolution

2 John Von Neuman original concept

3 Computer Architecture Evolution First computer was known as ENIAC (ELECTRONIC NUMERICAL INTEGRATOR AND COMPUTER). It was invented in 1946 at the University of Pennsylvania. Programming was done via hardwiring. John Von Neuman designed the EDVAC computer (Electronic Discrete Variable Automatic Computer) with the architecture used in today’s computers. It included stored programs and data. The first microprocessor was the Intel 4004 introduced in It was a 4-bit device with an Arithmetic Logic Unit, Control Unit and registers. The clock speed was 108KHz.

4 Computer Architecture Evolution 10 years later (1979 Intel introduced a 16-bit -internal bus, 8-bit- external bus microprocessor known as the The 8088 was used in IBM’s first Personal Computer. Intel's first 32-bit processor, the 386DX, was introduced in It was supplanted by the 486DX in The i486 featured a 32-bit architecture with on-chip data and address caches as well as an on-chip floating point processor. The 64-bit Pentium microprocessor was introduced in 1993 followed by the Pentium Pro, Pentium II (1997) and Pentium III.

5 Computer Architecture Evolution Today the latest microprocessor is Intel’s 2.2 GHz Pentium 4 with 512 MB of Cache memory. THE 5 BASIC COMPONENTS OF A COMPUTER ARE: –INPUT –OUTPUT –MEMORY –DATAPATH –CONTROL Datapath and Control are usually combined to form the processor.

6 Computer Architecture MAIN MEMORY (OFTEN REFERRED AS DRAM) –Bin for holding instructions and data for the applications run on the PC. –The processor grabs the information from this bin as needed and as dictated by the application running. DATAPATH –Performs the arithmetic Operations. CONTROL –Controls the flow of information between datapath, I/O devices, and memory.

7 Computer Architecture CACH MEMORY The cache memory is similar to the main memory but is a smaller bin that performs faster. The cache memory performs faster by accessing information in fewer clock cycles. Operating systems and applications use cache memory to store data or instructions that the processor is working with at the time, or is predicted to work with shortly; this allows the processor to get information quickly from the faster cache memory. The net result is a more efficient and faster running system. To keep the data and the instructions current, the system continuously updates the cache memory, moving information from your system's main memory to the cache memory