VIPER microprocessor facts for kids

The VIPER was a special kind of microprocessor designed in the 1980s by a group called the Royal Signals and Radar Establishment (RSRE) in the United Kingdom. It was made to be used in very important systems where safety was the top priority, like the computers in airplanes (called avionics).

What made VIPER unique was that it was the first commercial microprocessor design that was "formally proven" to be correct. This means that engineers used special math and logic to show that the chip would always work exactly as it was supposed to, without any hidden errors. This was a really big deal at the time!

What is VIPER?

VIPER stands for "Verified Integrated Processor for Enhanced Reliability." It was a 32-bit microprocessor, which means it could handle information in chunks of 32 bits at a time. Think of it like a tiny brain for computers, designed to be super reliable.

How Was VIPER Made?

The design for VIPER was finished in 1987. The RSRE first built a version of it using a technology called a "gate array." Later, a company named Marconi Electronics got a license to use the design. Marconi then created their own version called the MAS1908 VIPER-1. They used special manufacturing methods, including "CMOS" technology, to make the chips.

What Made VIPER Special?

VIPER was created specifically for "safety-critical" systems. These are systems where a mistake could be very dangerous or cause serious problems. For example, the computers that control an airplane's flight or manage power plants need to be incredibly reliable. VIPER was designed to meet these high safety standards.

How Did VIPER Work?

VIPER was a 32-bit processor. It could access up to 4 megabytes of memory and also 4 megabytes of "I/O space," which is where it talked to other parts of the computer. Even though its instructions looked simple, like those in some modern computer chips, the time it took to complete each instruction varied. Some instructions took 6 clock cycles, while others took up to 26. This was different from many newer chips that tried to complete one instruction every single clock cycle.

Programming VIPER: Newspeak

To make sure programs for VIPER were also very safe, a special programming language called Newspeak was created in 1984 by Ian Currie of RSRE. The main idea behind Newspeak was that any unexpected problems or "exceptional behavior" in a program had to be found and fixed when the program was being written, not when it was actually running. This helped ensure that the software running on VIPER would be as reliable as the chip itself.