# BIOS

> common firmware system used to initialize hardware when a computer boots

**Wikidata**: [Q226264](https://www.wikidata.org/wiki/Q226264)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/BIOS)  
**Source**: https://4ort.xyz/entity/bios

## Summary
BIOS (Basic Input/Output System) is a firmware system used to initialize hardware during a computer's boot process. It acts as an intermediary between a computer's hardware and its operating system, ensuring components like the CPU, memory, and storage are ready for use.

## Key Facts
- BIOS is a type of **computer firmware** that initializes hardware when a computer boots.
- It was invented by **Gary Kildall**, an American computer scientist (1942–1994).
- BIOS is a **de facto standard** for IBM PC-compatible systems and was used by early operating systems like **CP/M** and **Atari ST**.
- It is stored in **programmable read-only memory (PROM)** or **erasable programmable read-only memory (EPROM)**.
- BIOS has been largely replaced by **Unified Extensible Firmware Interface (UEFI)** in modern systems.
- Major manufacturers include **Phoenix Technologies** (founded 1979) and **American Megatrends (AMI)**.
- Variants include **AMIBIOS**, **Award BIOS**, and **SeaBIOS** (an open-source implementation).

## FAQs
### Q: What does BIOS stand for?
A: BIOS stands for **Basic Input/Output System**, a firmware that initializes hardware during computer startup.

### Q: Who invented BIOS?
A: **Gary Kildall**, an American computer scientist, is credited with inventing BIOS.

### Q: What replaced BIOS in modern computers?
A: **Unified Extensible Firmware Interface (UEFI)** has largely replaced BIOS in modern systems due to its advanced features.

### Q: What is the purpose of BIOS?
A: BIOS ensures hardware components (CPU, memory, storage) are properly initialized before the operating system loads.

### Q: Can BIOS be updated?
A: Yes, BIOS can be updated (flashed) to fix bugs or add support for new hardware, though this process varies by manufacturer.

## Why It Matters
BIOS played a crucial role in the early development of personal computers by providing a standardized way to initialize hardware before the operating system takes over. Without BIOS, early PCs would have required manual hardware configuration, making computing far less accessible. It bridged the gap between low-level hardware and high-level software, enabling the rise of IBM PC-compatible systems. While largely replaced by UEFI today, BIOS remains foundational in understanding how computers boot and interact with hardware. Its legacy persists in embedded systems and older devices, demonstrating its enduring impact on computing architecture.

## Notable For
- Being the **first widely adopted firmware** for IBM PC-compatible systems.
- Enabling **plug-and-play hardware initialization** before modern operating systems.
- Serving as the **predecessor to UEFI**, which now dominates modern firmware.
- Having **multiple implementations** (AMIBIOS, Award BIOS, SeaBIOS) by different manufacturers.
- Being **stored in non-volatile memory** (PROM/EPROM), allowing persistence without power.

## Body
### **Definition and Function**
BIOS is a **firmware** system embedded in a computer's motherboard. Its primary function is to:
- Perform **Power-On Self-Test (POST)** to check hardware integrity.
- Initialize and configure hardware components (CPU, RAM, storage).
- Load the **bootloader**, which then starts the operating system.

### **Historical Context**
- Developed in the **1970s–1980s** for early personal computers.
- Originally used in **CP/M** and **IBM PC-compatible** systems.
- **Gary Kildall** is credited as its inventor, contributing to its integration with early operating systems.

### **Technical Details**
- Stored in **PROM, EPROM, or flash memory** (later versions).
- Uses **BIOS interrupt calls** to communicate with hardware.
- Includes **setup utilities** (accessed via keypress during boot) to configure hardware settings.

### **Variants and Manufacturers**
- **AMIBIOS** (American Megatrends) – Widely used in PC motherboards.
- **Award BIOS** (Award Software) – Another major BIOS firmware.
- **Phoenix BIOS** (Phoenix Technologies) – Developed by a leading firmware company.
- **SeaBIOS** – Open-source implementation for x86 systems.

### **Decline and Replacement**
- **UEFI** (Unified Extensible Firmware Interface) replaced BIOS due to:
  - Support for **larger storage devices** (beyond 2TB).
  - Faster boot times and **secure boot** features.
  - Modern graphical interfaces and networking capabilities.

## Schema Markup
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  "@type": "Thing",
  "name": "BIOS",
  "description": "Common firmware system used to initialize hardware when a computer boots.",
  "sameAs": [
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## References

1. [Source](https://github.com/JohnMarkOckerbloom/ftl/blob/master/data/wikimap)
2. Freebase Data Dumps. 2013
3. Quora
4. National Library of Israel Names and Subjects Authority File
5. KBpedia
6. [OpenAlex](https://docs.openalex.org/download-snapshot/snapshot-data-format)