IBM, the computer giant of the time, initially dismissed the concept of the personal computer, but soon realized their mistake and in 1983 rushed out their PC. Crucially, and in stark contrast with Apple's policy, they opened up the system architecture. Anyone could build a PC, but only Apple could build an Apple or a Macintosh. Control of the technical specifications was more relaxed, leading to beneficial competition but creating difficulties of compatibility that are still acute today. That single decision, with Apple's dogged determination to keep tight control of manufacturing for their platform, led eventually to the dominance of the PC and the Windows platform. Large business installations could be delivered far more cheaply.
The original Macintosh computer, introduced in 1984, integrated all components except the keyboard and mouse into one small, elegant housing. Even without a hard drive (which was internal to the more powerful SE which followed in 1987), it was able to deal with anything that a home computer user might need at that time. By 1990, demands were increasing rapidly, particularly as music and pictures were arriving on the desktop. The Macintosh box and display screen became too small, and computers began to have more varied configurations reflecting the needs (and the wealth) of the owner. The Mac cost real money, thanks to their monopoly on manufacturing and a large profit margin, but they offered a reliable, user-friendly product which remained dominant in media areas while the PC took over business departments thanks to its low price held down by ruthless competition between hardware manufacturers.
The
processor is the heart of the matter, often referred to as the 'chip'. The
speed of a chip is the number of basic calculations (the change of
electronic state mentioned in The
Very Basics) that it can perform in a second, measured as a frequency.
For example, MHz stands for megahertz, a million changes per second;
one Hz is one cycle per second. The Windows platform is inextricably
intertwined with Intel chips, giving the
'Wintel' term reflecting the current monopoly that has drawn the interest
of the US government. Having used the Motorola G4 and then G5 chips for years, contemporary Macs use Intel chips
at speeds up to around 3GHz (gigahertz, 1000xmegahertz).
Chip speed is an increasingly unreliable guide to speed, as specialist
areas are created within chips to deal, for example, with multimedia
or to hold frequently-used instructions. In general, a Mac running at
the same nominal speed as a PC works considerably faster.
Closely connected with the central processor is the random access memory, or RAM. It is here that active applications and files are stored while the machine is running. These could, and used to be, stored on the internal hard disk, but the response of an electronic chip is many times faster. RAM is 'volatile', that is to say that when the power goes, so does its tiny mind. DRAM is functionally the same as RAM, although with different internal routines. The PowerPC chips introduced the racy 'backside cache', which is a small area of the chip that stores commonly accessed application instructions. There are also smaller, specialist chips embracing 'PRAM', which are user-adjustable but which can hold their memory when the power is turned off, retaining settings such as your highlight color and monitor size setting.
When buying a computer, never skimp on RAM. The more you have, the more applications you can have open at a time. It now costs just cents per MB (depending on how much you buy), down from 300 dollars in the late eighties. Don't hesitate to get more. The company that sells you the memory will be happy to advise on the model and what you should do. Some computers are very easy to fix yourself, but some need technical service. In general, PCs are far less easy to deal with than Macs.
Large,
complex applications will still need to access a disk for some functions,
particularly those which use large files such as for music, photographs and video.
'Virtual memory' is a method of extending the RAM's capacity by treating
the hard drive as a pretend chip. The downside, as mentioned above,
is that it's much slower, because you write information to a disk much
less quickly than to a chip. Although the home computer is fully
centered on the main processor chip, other specialized functions have
been broken out recently. Computers for heavier industrial applications
use 'parallel processing', whereby several chips operate in parallel
with computational tasks split between them. The programming needed can
be enormous in big installations, but desktop versions have been around since around 2001. The tremendous computation
needed by a color monitor is handled by separate video-RAM, or VRAM. Such
specialized breakouts will become more common as computers and entertainment
centers continue their much-hyped convergence.
Now, with the continuing convergence of traditional entertainment, communications and the computer, massive new demands are made on storage and processing. It has become more important to understand the different components and their interrelated functions: who does what and to whom.
History
of Apple Computer
Museum
of Obsolete Computers
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The
Big Help Desk
in
suggested reading order (links
are provided between pages)
all
photos by Jonnie Miles
Other
useful pages:
How to play music
Music playback options at the Stereo Society
Audio quality
Mono compatibility
MP3
Software Player Review (2001)
Surround
Sound: An Introduction
We encourage shopping:
Why our universal CD price is so low
What you get in packaging
Why CDs sound better
Why you get almost instant satisfaction: wait just three days for REAL quality
We give away HUGE chunks of music so you can REALLY check it out
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