Re: question on LED clock operation

I particularly like the definition from the people who provide
operating systems.

From our good friends at Microsoft: Any device capable of processing
information to produce a desired result. No matter how large or small
they are, computers typically perform their work in three well-defined
steps: (1) accepting input, (2) processing the input according to
predefined rules (programs), and (3) producing output.

From Micro2000uk: An electronic device for the storage and processing
of information.
From Teladesign: In general, a device that uses digital technology to
process and manipulate information.

From Euro Ecommerce: An "electronic device that accepts information in
digital or similar form and manipulates it for a result based on a
sequence of instructions.

From MCC: A device or system that is capable of carrying out a
sequence of operations in defined manner. The operations are frequently
numeric computations or data manipulations, but also include data input
and output.

New Zealand Economic Development: a programmable machine comprised of
hardware, including electronic components for the storage and
manipulation of digital signals and devices for storing, inputting and
displaying digital information.

And from our good editors at Wikipedia: A computer is a machine for
manipulating data according to a list of instructions, or program.
Computers take numerous physical forms. Early electronic computers were
the size of a large room, consuming as much power as several hundred
modern personal computers. [1] Today, computers can be made small
enough to fit into a wrist watch and be powered from a watch battery.
Society has come to recognize personal computers and their portable
equivalent, the laptop computer, as icons of the information age; they
are what most people think of as "a computer". However, the most common
form of computer in use today is by far the embedded computer. Embedded
computers are small, simple devices that are often used to control
other devices-for example, they may be found in machines ranging from
fighter aircraft to industrial robots, digital cameras, and even
children's toys.



Jack Denver wrote:
You're wrong - at best this makes them a "calculator". See for example
wikipedia:

"The ability to store and execute programs-that is, programmability-makes
computers extremely versatile and distinguishes them from calculators."

http://en.wikipedia.org/wiki/Computer

"John S." <hjsjms@xxxxxx> wrote in message
news:1166212387.498626.248780@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Jack Denver wrote:
I believe most definitions of "computer" imply the ability to execute
stored
programs - you need memory addresses for data and programs, a logical
instruction set, a command interpreter.

It has a program, albeit a very simple one to allow the storage and
manipulation of a simple repetitious dataset. And storage and
manipulation of data is what computers do.

Heck that little clock even has a monitor of sorts with a simple
display. May be more simple minded than an ADM3 dumb terminal.




An LED clock has none of those.

It most certainly does.

A clock is certainly an electronic digital
device and is capable of doing simple repetitive counting (so you could
argue that it is a form of single purpose "calculator") but I don't think
it's fair to call it a "computer" in the generally understood sense of
the
word.






"John S." <hjsjms@xxxxxx> wrote in message
news:1166198214.095272.216410@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Most definitions of a computer are some variation on it being able to
store and manipulate data. And indeed an electronic clock does store
and manipulate data, much like the simple built-in computers in a lot
of other consumer devices. A $5.00 LED clock from Wal Mart has a
monitor of sorts.


Jack Denver wrote:
You're wrong - there is no "computer" inside a simple LED clock -
there
are
just simple decade counter chips that divide the frequency of the AC
signal
and the only "clock" is the 60 hz line frequency. The only thing the
clock
needs to "compute" is whether a certain # of pulses have gone by -
its
basically an electronic version of counting on your fingers .
Commodore
64
was a full blown programmable digital computer that could do graphics,
word
processing, etc. - primitive by today's standards but still a far cry
from
a simple clock.

More on the basics of digital clock design here:

http://electronics.howstuffworks.com/digital-clock5.htm



<me@xxxxxxxxxxx> wrote in message
news:C5CdnYqW_LSYvh_Y4p2dnA@xxxxxxxxxxxxxxx


mcesar wrote:

I have dismantled in the past some of these LED clocks and, in my
experience, they use to use the 50/60 Hz mains frequency as the
clock
signal
of the digital circuitry (this 50/60 Hz even controls the LED
display
multiplexing).

Too slow. Even an old commodore 64 needed a million clock cycles
per second. 60 clock cycles in a second are not enough to run the
little computer inside the LED clock.





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