Computer Fundamentals and System Concepts

The Dynabook was conceptualized by Alan Kay at Xerox PARC in 1968 as the first portable personal computer concept. While not commercially produced then, it established the laptop form factor. HP, Dell, and HCL came later as manufacturers.

An Operating System (OS) is system software that manages computer hardware and software resources, providing services for computer programs. It controls all resources including CPU, memory, storage, and input/output devices.

Netbooks are a category of small, lightweight, and inexpensive laptop computers designed primarily for web browsing, email, and basic computing tasks. Their key characteristics are portability (lightweight) and connectivity (suitable for wireless communication), which distinguishes them from traditional heavier laptops.

The Intel 8251 is a programmable communication interface specifically designed as a Universal Synchronous/Asynchronous Receiver/Transmitter (USART). It handles both synchronous and asynchronous serial data communication. 8085 and 8086 are microprocessors, not communication peripherals. 8279 is a keyboard/display controller.

A retro virus is specifically designed to attack antivirus software and security programs to avoid detection. Unlike regular viruses that may avoid detection passively, retro viruses actively target, disable, or corrupt the antivirus programs themselves. Worms replicate across networks, trojans disguise themselves as legitimate software, and 'ghost virus' is not a standard classification. The key feature of a retro virus is its offensive action against security software.

A Trojan (or Trojan horse) is malicious software that disguises itself as legitimate software but does not replicate or copy itself. Unlike worms and viruses, Trojans rely on user deception to spread and typically create backdoors, steal data, or damage systems once executed. Joke programs are harmless, worms actively replicate, and hoaxes are false warnings about non-existent viruses. The defining characteristic of a Trojan is its non-replicating nature combined with malicious payload delivery.

RISC stands for Reduced Instruction Set Computer, a CPU design philosophy that uses a small, highly optimized set of instructions rather than a large complex set. RISC processors execute simpler instructions more quickly, typically in one clock cycle, leading to better performance and efficiency. The other options (Remodeled Interface System Computer, Remote Intranet Secured Connection, Runtime Instruction Set Compiler) are fabricated expansions that don't represent real computer architecture concepts.

A GPU (Graphics Processing Unit) is a specialized electronic circuit designed to rapidly manipulate and alter memory to accelerate the creation of images in a frame buffer intended for output to a display device. GPUs are essential for rendering graphics, video processing, gaming, and increasingly for parallel computing tasks like machine learning. The options Grouped Processing Unit, Graphical Portable Unit, and Graphical Performance Utility are incorrect expansions of this standard industry term.

The firewall is the security measure designed to protect systems, while Trojan Horse, Worms, and Virus are all types of malicious software (malware) that attack systems. A firewall is a defensive security tool, not an attack mechanism like the others.

The Intel 4004, released in 1971, was the first commercially available single-chip microprocessor. It was designed by Federico Faggin and had 2,300 transistors.

Intel's first financially successful product was the 3101 SRAM (Static Random Access Memory) chip introduced in 1969, which generated significant revenue and saved the company from bankruptcy. The 4004 was their first microprocessor, the 8085 was a later 8-bit processor, and the 4040 was an improved version of the 4004. The SRAM memory products were crucial to Intel's early success.

ENIAC (Electronic Numerical Integrator and Computer) was the first general-purpose electronic digital computer, completed in 1946 at the University of Pennsylvania. ABACUS is an ancient mechanical counting device, not electronic. Babbage designed the Analytical Engine in the 1830s, but it was mechanical and never completed. APPLE is a computer company, not the first electronic computer.

Using the multiplication principle of counting: multiply independent choices (4 monitors × 2 keyboards × 4 computers × 3 printers = 96 total combinations). Each component choice is independent of the others.