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Yeah, sort of, but it's more like this: First, there were computers. There were some that were made to be small enough for a group (IBM 1620, for example), an
by projektfu 4y ago
Yeah, sort of, but it's more like this:
First, there were computers. There were some that were made to be small enough for a group (IBM 1620, for example), and some that were large and intended as the central device for a large organization (IBM 7090). IBM referred to both as a "data processing system". These were delivered as batch-oriented systems.
Large computers like the 7090 often had smaller, accessory, general-purpose computers that handled things like card reading/punch and printing. For example, the PDP-10 had a PDP-11 as its front-end controller.
In the late 60s the term minicomputer appeared. A little while later, it became popular to refer to the large computers as "mainframe" computers. This probably was marketing speak to imply that, while minicomputers can be good for somethings, you wouldn't mini-frame your house, so you had better main-frame your company. I like to think about this time, which was also the heyday of database innovation, as the time when companies thought there would be many integrated applications running on the same data base [two words at the time] operated by a large, reliable computer and accessed by peripheral terminals. Through the 80s, people in companies often referred to "the computer" rather than considering multiple computers as the norm.
Microcomputers appeared with the development of the microprocessor. Certainly, the Altair 8800 started the wave of using a fully integrated microprocessor as the basis for a general-purpose computer. They grew out of calculators and, tellingly, from the project to develop an intelligent display terminal.
Micros often looked like minis in their use - they might be operated by terminals and punched tape, saving onto hard disks, floppy disks and magnetic tape. In my opinion, the distinction was if you used a discrete ALU, like the VAXes or the Xerox Alto, you were still using a minicomputer. Many minicomputers used ECL* to achieve high speeds that were not reachable by NMOS or CMOS logic at the time. Eventually, minicomputers also became microcomputers, for example, the MicroVAX. I think that these articles get it right that the microcomputers are different because they are not considered to be the orchestrator of a system of disks, tapes, terminals, printers, etc. They are at best part of a network with specialized microcomputers helping share resources when needed.
There is trend of data ending up in silos that happens with minicomputers and microcomputers. Applications get written for their own data, they aren't given direct access to other applications' data, and the data itself is geographically distributed.
As time has gone on, we now have the datacenter and virtualization. Data has been moving out of silos and into large, shared databanks. The computing unit is no longer made out of hardware, but rather represented by resources that can be provided in many virtualized ways.
* Emitter-coupled logic, a high-speed discrete logic often used in supercomputers and fast general-purpose computers until CMOS caught up with better power and heat characteristics.
- ghaff 4y agoAt the end of the day, a lot of the classifications are at least somewhat historical. And somewhat dependent on what operating systems they ran as well in addition to morphing in various ways over time. (At some level most modern servers are micros unless you're going to create a new category for them as you wouldn't usually refer to them that way.) You also have "Big Iron" Unix servers in there somewhere. And various specialty scientific computing systems, e.g. all the vector supercomputers etc.
- projektfu 4y agoYup, the categories are very fluid now. Considering how many businesses "run" on some various software packages these days, they all have some sort of mainframe, but it's not likely to be one computer. I think, only the minicomputer is really gone. There just isn't the same sort of way of using the computer that there was in that time.