Github

The GitHub service was developed by Chris Wanstrath, P. J. Hyett, Tom Preston-Werner, and Scott Chacon using Ruby on Rails, and started in February 2008. The company, GitHub, Inc., has existed as of 2007 and is located in San Francisco.GitHub at AWS Summit
The shading of the map illustrates the number of users as a proportion of each country's Internet population. The circular charts surrounding the two hemispheres depict the total number of GitHub users (left) and commits (right) per country.

On February 24, 2009, GitHub announced that within the first year of being online, GitHub had accumulated over 46,000 public repositories, 17,000 of which were formed in the previous month. At that time, about 6,200 repositories had been forked at least once, and 4,600 had been merged.

That same year, the site was used by over 100,000 users, according to GitHub,and had grown to host 90,000 unique public repositories, 12,000 having been forked at least once, for a total of 135,000 repositories.

In 2010, GitHub was hosting 1 million repositories, A year later, this number doubled. ReadWriteWeb reported that GitHub had surpassed SourceForge and Google Code in total number of commits for the period of January to May 2011.[30] On January 16, 2013, GitHub passed the 3 million users mark and was then hosting more than 5 million repositories. By the end of the year, the number of repositories was twice as great, reaching 10 million repositories.

In 2015, GitHub opened an office in Japan, its first outside of the U.S. In 2016, GitHub was ranked No. 14 on the Forbes Cloud 100 list.[34] It was not featured on 2018, 2019, and 2020 lists.

On February 28, 2018, GitHub fell victim to the third-largest distributed denial-of-service (DDoS) attack in history, with incoming traffic reaching a peak of about 1.35 terabits per second.

On June 19, 2018, GitHub expanded its GitHub Education by offering free education bundles to all schools.

Acquisition by Microsoft[edit]

Microsoft was on top of the list of the ten organizations with the most open-source contributors on GitHub in 2016.[39]

From 2012, Microsoft became a significant user of GitHub, using it to host open-source projects and development tools such as .NET Core, Chakra Core, MSBuild, PowerShell, PowerToys, Visual Studio Code, Windows Calculator, Windows Terminal and the bulk of its product documentation (now to be found on Microsoft Docs).

On June 4, 2018, Microsoft announced its intent to acquire GitHub for US$7.5 billion (~$8.96 billion in 2023). The deal closed on October 26, 2018.[42] GitHub continued to operate independently as a community, platform and business.[43] Under Microsoft, the service was led by Xamarin's Nat Friedman, reporting to Scott Guthrie, executive vice president of Microsoft Cloud and AI. Nat Friedman resigned November 3, 2021; he was replaced by Thomas Dohmke.
There have been concerns from developers Kyle Simpson, JavaScript trainer and author, and Rafael Laguna, CEO at Open-Xchange over Microsoft's purchase, citing uneasiness over Microsoft's handling of previous acquisitions, such as Nokia's mobile business and Skype.[45][46]

This acquisition was in line with Microsoft's business strategy under CEO Satya Nadella, which has seen a larger focus on cloud computing services, alongside the development of and contributions to open-source software. Harvard Business Review argued that Microsoft was intending to acquire GitHub to get access to its user base, so it can be used as a loss leader to encourage the use of its other development products and services.

Concerns over the sale bolstered interest in competitors: Bitbucket (owned by Atlassian), GitLab and SourceForge (owned by BIZX, LLC) reported that they had seen spikes in new users intending to migrate projects from GitHub to their respective services.

In September 2019, GitHub acquired Semmle, a code analysis tool. In February 2020, GitHub launched in India under the name GitHub India Private Limited. In March 2020, GitHub announced that they were acquiring npm, a JavaScript packaging vendor, for an undisclosed sum of money.The deal was closed on April 15, 2020.

In early July 2020, the GitHub Archive Program was established to archive its open-source code in perpetuity.

The Intel MCS-51 (commonly termed 8051) is a single chip microcontroller (MCU) series developed by Intel in 1980 for use in embedded systems. The architect of the Intel MCS-51 instruction set was John H. Wharton. Intel's original versions were popular in the 1980s and early 1990s, and enhanced binary compatible derivatives remain popular today. It is a complex instruction set computer, but also has some of the features of RISC architectures, such as a large register set and register windows, and has separate memory spaces for program instructions and data.

Important features and applications[edit]

i8051 microarchitecture

The 8051 architecture provides many functions (central processing unit (CPU), random-access memory (RAM), read-only memory (ROM), input/output (I/O) ports, serial port, interrupt control, timers) in one package:

8-bit arithmetic logic unit (ALU) and accumulator, 8-bit registers (one 16-bit register with special move instructions), 8-bit data bus and 2×16-bit address buses, program counter, data pointer, and related 8/11/16-bit operations; hence it is mainly an 8-bit microcontroller
Boolean processor with 17 instructions, 1-bit accumulator, 32 registers (4×8-bit, bit-addressable) and up to 144 special 1 bit-addressable RAM variables (18×8-bit)[4]
Multiply, divide and compare instructions
Four fast switchable register banks with eight registers each (memory mapped)
Fast interrupt with optional register bank switching
Interrupts and threads with selectable priority[5]
128 or 256 bytes of on-chip RAM (IRAM)
Dual 16-bit address bus; it can access 2×216 memory locations: 64 KB (65,536 locations) each of ROM (PMEM) and external RAM (XRAM), using two memory buses in a Harvard architecture.
On-chip ROM (not included on 803x variants)
Four (three full) 8-bit bi-directional input/output ports, bit addressable
UART (serial port)
Two 16-bit counter/timers
Power saving mode (on some derivatives)

https://lucid.app/lucidchart/e86e4e99-19b8-46aa-a23e-610c466295d8/view?page=0_0#

Typical RFDesignresource Design


 

8051 clones

The Apollo Guidance Computer (AGC) was a digital computer produced for the Apollo program that was installed on board each Apollo command module (CM) and Apollo Lunar Module (LM). The AGC provided computation and electronic interfaces for guidance, navigation, and control of the spacecraft. The AGC was the first computer based on silicon integrated circuits.The computer's performance was comparable to the first generation of home computers from the late 1970s, such as the Apple II, TRS-80, and Commodore PET.

1971
Computer Technology:
Intel releases first microprocessor, the 4004, a 4-bit central processing unit.

The databook offers some ways to use this thing there were not many use cases.

ARM (stylised in lowercase as arm, formerly an acronym for Advanced RISC Machines and originally Acorn RISC Machine) is a family of RISC instruction set architectures (ISAs) for computer processors. Arm Ltd. develops the ISAs and licenses them to other companies, who build the physical devices that use the instruction set. It also designs and licenses cores that implement these ISAs.

Due to their low costs, low power consumption, and low heat generation, ARM processors are useful for light, portable, battery-powered devices, including smartphones, laptops, and tablet computers, as well as embedded systems. However, ARM processors are also used for desktops and servers, including the world's fastest supercomputer (Fugaku) from 2020[6] to 2022. With over 230 billion ARM chips produced as of 2022, ARM is the most widely used family of instruction set architectures.