On May 12, 7:04 am, MooseFET <kensm...@rahul.net> wrote in
http://groups.google.com/group/alt.c...d03cb57?hl=en&
:
> On May 11, 10:00 pm, Radium <gluceg...@gmail.com> wrote:
> > On May 11, 6:26 am, MooseFET <kensm...@rahul.net> wrote:
> > > On May 10, 10:19 pm, Radium <gluceg...@gmail.com> wrote:
> > > > On May 10, 7:42 pm, MooseFET <kensm...@rahul.net> wrote:
> > > [.....]
> > > > > > 3. Magnetic parts
> > > > > Why would you care if it is magnetic? Non-linear magneto-optical
> > > > > effects could allow very fast logic at extremely low power levels.
> > > > Eventually the signal has to become electric for processing. Why waste
> > > > time converting signals from electric to magnetic [and visa versa]?
> > > I think you missed the point. The signals start out as keystrokes and
> > > mouse clicks and end up as dots on a CRT. We only make them into
> > > electronic signals because we have a very easy way to process
> > > electronic signals. There is no reason to not convert them to light
> > > or magnetic fields if that provides a way to process them very quickly
> > > at low power levels.
> > > [.....]
> > Okay, however, I don't see any advantage to converting electric
> > signals to magnetic signals. Optical, maybe or maybe not, depending on
> > the application. But definitely not magnetic.
> You have ruled out magnetics without having explored everything it may
> bring you. You need to imagine the PC you really want and not how it
> is done.
What are the advantages of magnetics vs. electrics?
> Think of a box with a monitor and keyboard etc plugged into it. You
> can't see into the box all you know is that it does everything you
> neede it to do, there are no moving parts, it draws very little power
> and will have a life over 100 years.
Okay.
> If this is the PC you want, why are you setting limits on whats inside
> it beyond that?
It's a matter of personal preference.
> > > > > > 5. ROM
> > > > > Why no ROM. It is very handy stuff.
> > > > Because I prefer that the info usually stored in ROM, be generated in
> > > > real-time.
> > > The "generated in real-time" step requires hardware that knows what to
> > > generate. How do you propose that the hardware knows what to do.
> > > Remember that logic gates can perform AND and OR operations but they
> > > can't create information. All the information must come from
> > > somewhere.
> > I am starting to understand. In my dream PC the hardware gets its
> > instructions on what to generate in a similar manner in which SB16
> > ISA's FM synth chip gets its instructions on what to generate. So some
> > amount of ROM maybe required here. If so, then yes, my dream PC would
> > use ROM, but only when and where it is mathematically-necessary in
> > order to have an efficient PC with the advantages of other PCs. My
> > dream PC uses as little ROM as mathematically-necessary to have the
> > benefits associated with the world's current best PC. Other than that,
> > my dream PC is virtually ROM-free.
> A PC with the mathematically low amount of ROM would by its nature be
> slow.
Why?
> I'm sure you have "zipped" and "unzipped" files. The process
> of unzipping is converting a lower number of bits into a larger number
> that are easier to deal with in software. It takes a while to do this
> process. This extra time is what you would be adding to your PC.
>
> [....]
I don't use zip, unless I really need to. So far, I've never had to.
Winzip is a pain in the @$$.
> > So what you're saying is that the keyboard is a form of ROM. Do I
> > guess right?
> No, it contains one. The buttons and stuff are there too and they
> aren't ROM.
Is the ROM built into the keyboard?
On May 12, 8:05 am, Stephen Fuld <S.F...@PleaseRemove.att.net> wrote
in
http://groups.google.com/group/alt.c...5830c13?hl=en&
:
> MooseFET wrote:
> > On May 11, 10:00 pm, Radium <gluceg...@gmail.com> wrote:
> >> So what you're saying is that the keyboard is a form of ROM. Do I
> >> guess right?
> > No, it contains one. The buttons and stuff are there too and they
> > aren't ROM.
> Radium, perhaps this simplified example of a keyboard will help you to
> think through what you are talking about.
Okay.
> Let's look at the requirements. You have about 100 switches (keys) and
> when each one is pressed, you want to output a specific 8 bit pattern
> (the ASCII code for the key). The logic for this is pretty simple to
> synthesize. You have 100 circuits, each similar to each other but
> slightly different. Each one, when corresponding the switch is pressed
> enables a pattern of logical highs and lows to the output bus. This
> will work, but now you have 100 separate circuits. If each circuit was
> one one chip, it would take 100 chips. OK, no one would do that - you
> certainly would combine them. But now you have a chip with 100 inputs
> and pins are expensive. So let's say we arrange the switches in a 10 by
> 10 matrix so that what is output when a switch is pressed is the row and
> column of the matrix corresponding to that switch. So now you have 20
> inputs. But with an other simple circuit you can use a 4 bit value to
> indicate which of the 10 rows the pressed key belongs to. Similarly for
> the column. Now we are down to 8 bits. These can be fed into a chip
> that decodes these 8 inputs (again, easy to synthesize) into one of 100
> lines. These in turn select one of 100 patterns of logic highs and lows
> to output.
Interesting. In '90, I had a green monochrome Corona PC. Its keyboard
did not connect to the PC via pins but rather through a cord
resembling a telephone cord. The plugs on both ends resembled that
used for telephones.
> This chip, the one that takes the 8 inputs (AKA address) and
> outputs a particular pattern (AKA data) *is* a ROM.
What are the alternatives to ROM?
> There is nothing
> inherently wrong with ROM, it is just a more convenient and lower cost
> way to do what you could otherwise do with discrete logic.
I am aware that there is nothing objectively wrong with ROM. However,
as a matter of personal preference, I would like other alternatives.
It's like preferring garlic over onions [or visa versa].
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