Microsoft open sources 6502 BASIC, a key piece of computing history

[Alfonso Maruccia]

Home Computer Archeology: Few early Microsoft products left as lasting a mark as 6502 BASIC. The interpreter introduced millions of people to computers and programming, shaping the next generation of software developers. Redmond is now releasing the original software, letting developers explore the code or even build something new from it.

A few months after releasing the Altair BASIC source code, Microsoft has shared another cornerstone of its early software success. The company announced that 6502 BASIC is now open source, giving programmers and archivists access to the official product after decades of relying on "unofficial" copies and fragments.

Microsoft recently released the code designed for the MOS Technology 6502 CPU, an influential 8-bit microprocessor introduced in 1975. A small team at MOS designed the 6502 as a simplified, less expensive, and faster alternative to the Motorola 6800.

Along with the Zilog Z80, the MOS chip formed the foundation for some of the most influential computing devices that fueled the home computer revolution in the early 1980s. The 6502 and its variants powered iconic machines such as the Atari 2600, Apple II, NES, Commodore 64, and many others.

Bill Gates and Ric Weiland ported 6502 BASIC from the original Altair version, and Commodore licensed it for a $25,000 flat fee, incorporating it into the VIC-20 and Commodore 64. Microsoft notes on the software's GitHub repository that the BASIC interpreter introduced millions of people to computers and programming through its approachable syntax.

Many programmers who later became leaders in the IT industry cut their teeth on Microsoft's BASIC, which became the de facto standard for computer programming. The 6502 version also played a key role in Microsoft's history, demonstrating the viability of software as a standalone business separate from hardware products.

Microsoft learned valuable lessons from porting BASIC to the 6502. The company notes that its multi-platform approach and development techniques later informed the creation of MS-DOS and Windows. The GitHub repository includes BASIC version 1.1, which incorporates additional fixes contributed by Commodore in 1978.

The new 6502 BASIC open source release took considerable effort to make happen. Microsoft collaborated with Michael Steil, who documented and rebuilt the original for multiple target systems. The GitHub release draws on Steil's work, providing the full BASIC interpreter in its most complete form.

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Microsoft open sources 6502 BASIC, a key piece of computing history

 

[ferrellsl]

Microsoft never gives anything away unless they've found it to be worthless. And the ROMs containing BASIC were dumped and disassembled decades ago so there are no secrets to uncover in this open source repository. This is merely a publicity stunt to make Microsoft look as if they've become open source "friendly".

 

[unoficialoficial]

The classic 8-bit 6502 CPU had roughly 4,000 transistors that are visible to the naked eye and running at about 2 MHz. By today's standards, it might seem underwhelming. However, its performance is comparable to the CPU that powered the Apollo 11 mission's Apollo Guidance Computer (AGC), which guided astronauts to the Moon and brought them safely back—all with that modest amount of processing power.

 

[Liranan]

The classic 8-bit 6502 CPU had roughly 4,000 transistors that are visible to the naked eye and running at about 2 MHz. By today's standards, it might seem underwhelming. However, its performance is comparable to the CPU that powered the Apollo 11 mission's Apollo Guidance Computer (AGC), which guided astronauts to the Moon and brought them safely back—all with that modest amount of processing power.

Not everything requires a massive data centre to run, a lot of things run on very basic chips as that's all they need.

 

[guillejp]

It's a very cool museum exhibit, that's it. It's 50 years old, it doesn't have to have any practical use today and in fact that's why they're ok to release it, but no need to overthink it. Just enjoy it as the historical piece it is.

 

[llamapanda]

It's a very cool museum exhibit, that's it. It's 50 years old, it doesn't have to have any practical use today and in fact that's why they're ok to release it, but no need to overthink it. Just enjoy it as the historical piece it is.

And yet there are enthusiast groups out there still making new games for historic hardware to this day. It has a practical use via entertainment and education even if you see no direct commercial value. The release is valuable as it legitimises people using it who previously had to reverse engineer or hack it out of things. It may not be as big a deal as if Nintendo suddenly decided to allow emulation but it's still an important step.

 

[guillejp]

And yet there are enthusiast groups out there still making new games for historic hardware to this day. It has a practical use via entertainment and education even if you see no direct commercial value. The release is valuable as it legitimises people using it who previously had to reverse engineer or hack it out of things. It may not be as big a deal as if Nintendo suddenly decided to allow emulation but it's still an important step.

It's an extremely niche use case... Do you wanna raise the case for an extremely nice use case? Okay, raise the case for an extremely niche use case. Good? Mkay.