The B 5000
By now, at least a few of you would probably like to remind me that IBM was not the only company to make a computer since the UNIVAC. Your point is well taken, so let us take a look at a machine from Burroughs, the B 5000. This is a really interesting machine, especially considering that it was announced in 1961. In fact, to this day, UNISYS still supports the software.
The B 5000 was developed for high-level languages, namely COBOL and ALGOL. By this I mean the machine language was created mainly for easy translation from higher-level languages. It contained a hardware stack, segmentation, and many descriptors for data access.
The descriptors had many uses, which included allowing bound checking in hardware, distinguishing between character strings and arrays of words, easing dynamic array allocation, indicating the size of characters, and even whether something was in core memory or not. Why would we need that? In two words, virtual memory. The B 5000 was the first commercial computer with this technology. It also supported multiprocessing and multiprogramming, even with ALGOL and COBOL. In fact, the Master Control Program (MCP), as the operating system was called, handled memory and input/output unit assignments, segmentation of programs, subroutine linkages, and scheduling, which freed the programmer from all these tedious and time-consuming tasks.
Another aspect Burroughs was proud of was the modular nature of the computer. It could be increased or decreased, without costly "reprogramming" of the entire machine.
The B 5000 was not the commercial success IBM mainframes were. In fact, it was sometimes referred to as the machine everyone loves but no one buys. However, its design was nothing less than elegant and efficient. It focused on solving problems within the context of how humans interacted with and related to computers, as opposed to speed for the sake of speed. Perhaps more importantly, some of the technologies it introduced, like virtual memory and multiprocessing, are necessities in present computers, some of which still support this magnificent architecture 48 years after it was introduced.