myq,
it still is not clear, but perhaps we can sort it out.
Linux OS will not make it more expensive. Since it can be
made small, it would be a cost-effective choice.
This organisation is discussing theese issues
(embedded Open OS choices)
http://www.handhelds.org/geeklog/index.php
It look like you are thinking of a custom made hardware?
A handheld device, which would act as a calculator
and also have (wireless?) email? Here are few resources
http://www.airora.com/web/Linux+OS.html
Another choice is Simbian OS
http://www.linuxinsider.com/story/34648.html
http://www.linuxdevices.com/news/NS9400436382.html
or java
http://alllinuxdevices.com/news_story.php3?ltsn=2003-02-19-002-07-IN-BU-TP
Custom hardware usually means custom chips, depending
on how many you need, a custom design and parts.
That can be very expensive, form $1000 to hundreds of $1000.
You would have to come with a real spec, before cost
can be estimated. Here is an example of specs and issues
http://www.wapforum.org/what/technical.htm
Would an existing hardware do? A laptop? Unless You need thousands of them,
you may want to avoid hardware developement and just hack (re-program)
existing device.
For example, better mobiles (cell phones) have built-in calculator
and ability to send email. Some also use OS and can be programmed.
So, chances are, you can make them do what you need. In this case,
bit-mapped display is already built in.The incremental cost of bitmapped
display over character generator based one is small these days.
You save on video memory. Again size (tech spec) would be important to know.
Search terms: mobil calculator GPRS
brings examples of mobiles which have basic fuctions
(GPRS allows e-mail), such as
... a alarm clock, instant messaging or a calculator. GSM/GPRS. ...
www.free-usa-mobile-cell-phones-wireless-cellular-deal.com/ cell-phones.htm
or linux based PDA
www.pdastreet.com/boards/LinuxPDAs/messages/118.htm
.
I would pick one and see what I do in software, before trying to build one.
good luck
hedgie |
Request for Answer Clarification by
myq-ga
on
23 Jul 2004 08:27 PDT
i am afraid my question remains unanswered.
I wanted tknow whether (if one is interested in building a handheld
device from scratch, using a processor etc) would using linux (as
opposed to no OS) mean a substantial increase (how substantial?) in
COMPONENT costs (not development costs)
Someone else (here) has suggested that the problem with Linux is it is
a memory and processor hog Your answer seems to suggest that using or
not using linux (and using or not using a graphical lcd instead of a
character based one) has no implications for the kind of processor
power that is required. If it does have implications, what are they:
i.e by what factor (obviously a very very rough idea is all that is
asked for)
I am not really asking for general links but specific answers to what
I am asking. thanks
|
Clarification of Answer by
hedgie-ga
on
23 Jul 2004 13:44 PDT
myq-ga
I gave you you couple of general links to illustrate how a spec
looks, what factors play role. The way it is now, it is like asking:
what it would cost to build a house? Is it cheaper to use shingles or
tiles for the roof.
To answer that, one would need to see the architects plan for the house.
If you are making a mass produced device, you may spend $10000 to save a $1.
You have to sell 10000 units to make that pay. If you are building
one unit. math is different.
If I you are building one unit, you want to minimize the developepment
cost. Linux can fit on one floppy and allows you to use higher level tools
(like c) then if you would do everything from scratch (no OS).
So, both views can be defended, and answer depends on number of units to be made.
For one unit, or ten, it is best to use exisiting hardware and just program it
to do what you need. Good hardware (a mobil with bit mapped display) sells for
anything between $200 to $600. That is small cost compared to cost of
developement of custom low level (no OS) software. It may save you 20$
in
components costs.
That too would deepend on size of the display - which, so far
was not specified. Bit it should give you order of magnitude estimates.
hedgie
|
Request for Answer Clarification by
myq-ga
on
23 Jul 2004 14:17 PDT
As I explained, I am not interested in the development cost. I am
interested in the component cost alone. That is, the per piece cost of
the hardware itself.
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Clarification of Answer by
hedgie-ga
on
23 Jul 2004 22:14 PDT
OK
Cost of memory .. 8M .. $15
http://www.epinions.com/cmhd-Memory-Readers-All-4_8_MB
8M will store linux OS (1 floppy is 1.4 M) and also
support 200 x 200 bit mapped display.
Here are links for small linux
http://www.superant.com/smalllinux/
Linux is used here in the strict sense
as OS only. In common parlance, people use "Linux" to mean
Linux Kernel plus many applications - as discussed e.g. here
http://www.balug.org/ml/balug-talk/msg02522.html
|
Request for Answer Clarification by
myq-ga
on
23 Jul 2004 22:53 PDT
I am sorry to pester you so (and did not do so in your answer to an
earlier question) but I was interested in COMPONENT costs (not memory
costs alone) you have not mentioned the kind of processor that is
typically required for a mini linux distribution (one, e.g, which will
fit on a floppy)
Or the kind of processor that can handle the power required for a
graphical LCD (very easy tasks but requiring minor drawing of menu
items)
|
Request for Answer Clarification by
myq-ga
on
23 Jul 2004 23:55 PDT
Also, you have given the price for 8MB RAM (it seems) but can linux be
installed on RAM (other stuff , like data, would also be in RAM) Would
it not require ROM or FlashMemory or floppy or hardrive?
As to the processor question, would a z80 clone or variant be able to
handle small scale linux or an lcd graphical display (very very basic
menus). If not what sort of processor would and what is the cost?
If you can answerr, I am prepared to increase the amount (i.e. pay extra)
|
Clarification of Answer by
hedgie-ga
on
24 Jul 2004 12:38 PDT
Hi again Myq
The question was,
is Linux a memory hog, is bit mapped display memory hog,
and will therefore their use make hadheld , networked
calculator significantly more expensive?
Answer is no. Difference in memory as small,
memory is cheap, and other componnents are the same.
How much are the other components?
I have no idea. The device was not designed yet.
Even if you add to the price, I cannot design it since
I do not know what it has to do.
I assume it is handheld and wireless,
but I really do not know. It would be irresponsible to just
pretend that I do.
To post a new question usually works better then promise of a tip and expansion
of an old question. I also suggest you look
at the art of formulating a question first before you post the next one.
://www.google.com/search?hl=en&lr=lang_en&ie=ISO-8859-1&safe=off&q=art+of+question+asking
http://answers.google.com/answers/faq.html#persistentcookie
Good question is half of an answer, and I, I am afraid, can only supply
that second half. You get more for your money if the first half is good.
Linux can run entirely in RAM, but of course, you need some
non-volatile memory to load it.
Which one, that depends on function.
"It" (whatever it is) can be done with Z80, but you may need a crosscompiler.
"...z80as is a Zilog Z80 assembler that I have written. It supports
all documented Z80 instructions, Z180 Instructions, "unsuported" Z80
Instructions, labels, various directives, and many other things. I
have gotten it to compile and function correctly on an x86 GNU/Linux
system as well as an x86 FreeBSD system, and it should compile and run
on any Unix system with the gcc. By hacking the sourcecode a bit, I
was able to get it to compile under Cygwin and MinGW, which means that
there is a windows version. .."
http://z80as.sourceforge.net/
Linux runs on many processors, e,g,
http://www.mlinux.org/projects/present/mlugintro/img6.htm
even tough, one would probably buy a already assembled board, which:
"...By providing ready-to-use BSPs with an integrated support
structure provided by MPC Data, the development of products based on
Embedded Linux becomes easy and uncomplicated".
http://www.electronicstalk.com/news/ren/ren128.html
The uncomplicated is relative.
It is still easier, and best, to use existing product and just program it.
Since I do not understand why such 'common sense strategy' is not aceptable,
I really do not know how I can guess what components may needed.
After your latest clarification, I think best way to get a feel for
cost/function tradeoff of the hradware is to review high end cell
phones. You will see that
price goes up with resolution and color vs B&W display, with amount of memory,
and quality of the built in calculator. You will have to pay for the
same components
mobile designer had to use to achieve those functions.
hedgie
|
Request for Answer Clarification by
myq-ga
on
24 Jul 2004 14:19 PDT
I would simply like to know whether "small scale linux" (i.e. bare
minimum linux but one which can connect to the net. For example, let
us say one simply wants to email to a prespecified address AND NOTHING
ELSE) can run on a z80 variant and how much (ABOUT) would such a z80
variant cost.
Also, would the processor that could run bare-bones linux also do
bitmapped LCD displays (like, say draw a a somewhat variable sized
square, a smiley, and a circle and like select either of the three
figures and show a different prefed message for each)?
Surely the question(s) are well defined now. This is (now) all I am
asking that the system do. The components which matter pricewise are:
the processor, the lcd, the modem chip, the memory.
The address you have given for what Linux runs on does not seem to
have z80 variants. In fact it seems to have high end or medium end
processors. That must mean it is not a bare bones linux they are
talking about
The stuff about the z80as seems irrelevant as I want to know whether
barebone linux can run on a z80 and not whether z80 code can be made
to run on some x86 system.
|
Clarification of Answer by
hedgie-ga
on
24 Jul 2004 20:08 PDT
"I would simply like to know whether "small scale linux" (i.e. bare
minimum linux but one which can connect to the net..."
YES. The one I have on a single floppy will detect network,
runs totally in RAM and provide basic commands, mount, ls, fdisk ..
It is called Toms's rescue disk... Free from the net, but another question.
"..e, say draw a a somewhat variable sized
square, a smiley, ..:
System I mentioned has no X. Graphics would have to be designed but
mobile phones have logos. icons, even tunes., they do not use X though
(a graphic windows which usually come with Linux).
" That must mean it is not a bare bones linux they are
talking about
The stuff about the z80as seems irrelevant .."
It may be necessary to study (or aks another question) about crosscompilers
to undestand how existence of z80 answers your question. That too is beyond
the scope of original question.
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