Information Technology

VAX In the mid 1970 Digital Equipment Corporation (DEC) developed a minicomputer called VAX. It was made on Instruction Set Architecture (ISA). VAX 11/780 was, introduced in October 25 1977, was first of a range of popular computers built on that architecture. VAX has been known as very essential equipment, because of its very large number of programmer-friendly addressing modes and machine instructions and instructions for complex operations such as queue insertion or deletion and polynomial evaluation. Its processor had 32-bit of address bus also having CISC and virtual memory architecture. It had its native operating system called VAX it was renamed as Open VMS in 1991 or early 1992.

PDP-8 In 1965 Digital Equipment Corporation (DEC)  Introduced PDP-8, and sold more than 50,000 systems. It was a very low cost computer and its availability in large volume of units made new people accessible for their use. PDP-8 had only eight instructions and two registers (a 12 bit accumulator, AC, and a carry bit called the "link register", L). It used magnetic core memory with a cycle time of 1.5 µs , so that a typical two cycle  (fetch, execute) memory reference instruction ran at a speed of 0.333 MIPS.

IBM 7090 This computer was built by IBM in 1959. It was designed for large scale scientific and technological applications. The 7090 used a 36 bit word length, with an address space of 32K (32,768) words. It operated with a basic memory cycle of 2.8µs. This was built using transistor circuits. It had a processing speed of around 100K flops the 7090 was six times faster than the 709 (early version of IBM which used vacuum tubes and was  costly to rent) and can be rented for half the price. It was widely known to be transistorized version of the vacuum-tube-logic 709 computer. It was redesigned to be compatible by Sylvania who was the data processing subcontractor    BMEWS   missile warning radar network, which was under a mandate to use transistor computers.Couple of this unit were used for American Airlines SABRE real-time airline reservation system. It was intended mainly for scientific computing, but it was also suitable for business and administ...

Universal Automatic Computer (UNIVAC-I) In 1951 AD, Dr. John William Mauchly and John Presper Eckert had developed the first general purpose electronic digital computer for commercial users. It was based on the EDVAC design. It could handle both numbers and alphabet characters. It had mercury delay lines for strong programs. A magnetic tape was used for data input and output. It contained 5600 vacuum tubes, 18000 crystal diodes and 300 relays.

Electronic Delay Storage Automatic Computer (EDSAC) In 1949 AD, Prof. MauriceWilkes and his team developed the first practical stored -program electronic computer at the university of Cambridge Mathematical Laboratory in England. It is called EDSAC. It contained 3000 vacuum tubes and used memory delay lines for memory. The programs were input in the EDSAC by using paper tape and outputs were displayed through the teleprinter (Electromechanical Typewriter). Pic:   Creative Commons   Attribution 2.0 Generic

Electronic Discrete Variable Automatic Computer (EDVAC) Dr. John William Mauchly, John presper Eckert and John von Neumann had developed the first stored program computer called Electronic Discrete Variable Automatic Computer (EDVAC). It was based on binary number system. It had stored program, central processor and memory for both data and programs. The memory device used in it was magnetic tape. It contained almost 6000 vacuum tubes and 12000 diodes.

Electronic Numerical Integrator and Calculator (ENIAC) Dr, John William Mauchy and John Presper Eckert developed the first general purpose computer, Electronic Numerical Integrator and Calculator at university of pennsylvania's Moore School of Electrical Engineering, USA in 1943 AD. It was 1000 times more faster than other computers.The ENIAC was based on the decimal number and contained 18000 vacuum tubes. It was faster than previous machines. It could perform many complicated arithmetic operations in less than a second.   Creative Commons   Attribution 2.0 Generic