It's 50 years since IBM launched the first System/360 mainframe.
The S/360 was a landmark that marked the arrival of modern computing. It introduced processing techniques that would become commonplace, such as lookahead pipelining, branch prediction, multitasking, memory protection and generalised interrupts. It's a reminder that many architectural tricks used inside chips today date back to before man landed on the moon.
But perhaps more importantly the System/360 achieved the modern reality of a general-purpose computer that could be easily upgraded.
Before the System/360, computers were usually replaced rather than upgraded, as different generations of machines didn't mix. New systems were generally incompatible with older models, with each machine usually relying on a bespoke OS, peripherals and software. Mainframes were also usually designed to tackle a specific task - for example, a particular scientific or commercial job.
The System/360 family of machines were upgradable, sharing software, OS and peripherals and able to tackle a range of workloads - paving the way for the adoption of mainframes throughout the worlds of business, industry and science.