On Mar 20, 2:38 am, wrote:
On Mar 20, 3:17 pm, wrote:

For $500 you can get a new laptop with twice the disk space and twice
the procesor speed, and a 15" screen. (frys.com, or your prefered
discounter)
I would not in-dash-mount a computer, as you arel likely to replace it
from time to time. Plus, you might like it to be portable sometimes.

Hi Chris;
I see two advantages of a VIA solution for onboard PC over a laptop;
power consumption and fanless, so the motherboard can be isolated from
the marine environment.

Cheers, Jim

Hi Jim,

power consumption is a function of the price (and year) of the
laptop. In the $500 range I wouldn't expect huge differences between
laptop and the VIA box, they will both run on the same (cheap) parts.
[As others said, the screen is by far the largest power draw; included
in the specs you get for the laptop, but not for the box, if I
understand correctly.]

Fanless is nice, but unless you waterproof the box _and_ the sreen,
there is no real advantage over a laptop. You can't douse either
system with sal****er. (Remember, the motherboard is probably cheaper
than the screen. )
Btw., the the laptop fan is not blowing over the motherboard, just
through the heatsink of the processor. (At least in the last one I
took apart.)

I totally agree with Jeff: For ease of use and economics: A laptop.
For high fail safety at a reasonable price: Two cheap laptops, keep
one sealed in plastic as a backup.
For the joy of tweaking and optimizing a neat system: The VIA box.

Have fun,

Chris

Thanks Jeff, Chris, Wayne;
Your opinions have altered my course; I'm looking in the laptop
direction now. One for use and one sealed as a spare. I've always
built my own computers and as you said, a VIA box would be fun to
build but with a critical application (like running navigation
software) you have to be practical. I'm building a 35' steel
pilothouse cutter and haven't calculated my power requirements yet,
but I'm considering a towed generator. The monitor will be housed in
the pilothouse, where it will be dry.

A navigation solution that will work in the cockpit is another issue!

Cheers, Jim

Another View:

Basic Question: Are you planning to be able to "use" the computer from
the helm position?? If so, you will not want to put a typical laptop
in that location. How do you see the screen and operate the laptop?

IF you want a helm-position usable computer for navigation,
monitoring, and possibly onboard controls, then I think the VIA and
similar machines are the way to go. The system mounts in a protected
position, but runs sealed/fanless for high reliability in Salt Air, a
LCD Display (lots of issues and variants and prices) is viewable at
the helm, and some variety of hands-on control (again, many
possibilities) are at the helm position.

The newer VIA units have MP4 video acceleration in the chipset and can
play DVD movies successfully. At Anchor! Unless you want to watch and
listen to Victory At Sea while underway :-)

I'm researching the possibilities and will build some system like this
starting in late May when I get back to the US.

There is a new "WIKI" section of www.boatdesign.net and I'm helping
put together a "Onboard Computers" section. You're invited to drop in
there (http://boatdesign.net/wiki) and help out!
There a discussion section (Tab at the top) so please say hello...

I haven't followed this group, but I will from now on.. Obviously the
only reason for all this stuff is to Get Out There.

* wrote, On 3/22/2007 3:58 PM:
Another View:

Basic Question: Are you planning to be able to "use" the computer from
the helm position?? If so, you will not want to put a typical laptop
in that location. How do you see the screen and operate the laptop?

You simply use a screen and keyboard, the same way you do with the Via
box. Every laptop I've ever seen supports that; USB and Bluetooth
makes it trivial.



IF you want a helm-position usable computer for navigation,
monitoring, and possibly onboard controls, then I think the VIA and
similar machines are the way to go. The system mounts in a protected
position, but runs sealed/fanless for high reliability in Salt Air,

Sealed??? How does that work? The only way it can run fanless is
with good ventilation.

a
LCD Display (lots of issues and variants and prices) is viewable at
the helm, and some variety of hands-on control (again, many
possibilities) are at the helm position.

Anything you can do with the mini-itx box you can also do with a laptop.


The newer VIA units have MP4 video acceleration in the chipset and can
play DVD movies successfully. At Anchor! Unless you want to watch and
listen to Victory At Sea while underway :-)

Most laptops you buy now do the same. My fist DVD player was an IBM
Laptop bought in 2000. But the economics are such that having a
portable DVD player is better. Or a DVD/TV combo. There are lots of
combinations that work.



I'm researching the possibilities and will build some system like this
starting in late May when I get back to the US.

There is a new "WIKI" section of www.boatdesign.net and I'm helping
put together a "Onboard Computers" section. You're invited to drop in
there (http://boatdesign.net/wiki) and help out!
There a discussion section (Tab at the top) so please say hello...

I'd like to see the possibilities. But the truth is I can buy a used
laptop for less money than a mini-itx motherboard with memory, so
there's no way the economics favor the homebuilt.


I haven't followed this group, but I will from now on.. Obviously the
only reason for all this stuff is to Get Out There.

"Jeff" wrote in message
. ..
* wrote, On 3/22/2007 3:58 PM:
Another View:

Basic Question: Are you planning to be able to "use" the computer
from
the helm position?? If so, you will not want to put a typical laptop
in that location. How do you see the screen and operate the laptop?

You simply use a screen and keyboard, the same way you do with the Via
box. Every laptop I've ever seen supports that; USB and Bluetooth
makes it trivial.



IF you want a helm-position usable computer for navigation,
monitoring, and possibly onboard controls, then I think the VIA and
similar machines are the way to go. The system mounts in a protected
position, but runs sealed/fanless for high reliability in Salt Air,

Sealed??? How does that work? The only way it can run fanless is
with good ventilation.

Heat sink principle with surface area heat radiation. Duh!

Wilbur Hubbard

* Wilbur Hubbard wrote, On 3/22/2007 5:24 PM:

Sealed??? How does that work? The only way it can run fanless is
with good ventilation.

Heat sink principle with surface area heat radiation. Duh!

So why don't you explain just how you would do this with a VIA
motherboard.

No, forget it, please don't. It would be too embarrassing for you.

I'd like to see the possibilities. But the truth is I can buy a used
laptop for less money than a mini-itx motherboard with memory, so
there's no way the economics favor the homebuilt.

The thing is with crictical systems we want redundancy (backup), and
this includes PC's.
Besides navigation, PC's can be used for a number of 'black box'
applications, including AIS and fish finder to name a couple. Also,
there is the SSB radio interface with a PC. So a back-up system is
even more vital.

So you really need to double the cost differential between a laptop
and other options when you're calculating the economics of it.
Roughly, you can buy two laptops for the cost of a single mini-itx
system. The laptops will be slightly faster and use slighlty more
power. Many laptops seem to survive ok in the marine environment
without being sealed even if it was possible to do. Of course another
option is to have a mini-itx with a laptop backup(-:.
Cheers, Jim

On 22 Mar 2007 17:51:54 -0700, wrote:

Besides navigation, PC's can be used for a number of 'black box'
applications, including AIS and fish finder to name a couple. Also,
there is the SSB radio interface with a PC. So a back-up system is
even more vital.

Yes. I have one laptop more or less dedicated to navigation - chart
plotting and track logging, and a second laptop used most of the time
for SSB or internet communications - WiFi, Sprint Aircard, Winlink,
EMAIL, Weather FAX, NAVTEX, etc. On extended cruises we also bring
along the admirals laptop which can back up either of mine or be used
with WiFi when in port.

I typically by laptops that are used/off lease/reconditioned/etc.,
rarely paying more than $300. My present navigation workhorse is a
Panasonic Toughbook which is built to near military standards and has
an exceptionally bright screen. That one was a bit over $400.

Sealed??? How does that work? The only way it can run fanless is
with good ventilation.

Sure you can, several of the newer home theatre types of PCs use extended
heat sinks to dissipate the heat from their CPU, video and I/O chipsets. So
while that particular case and motherboard might not lend itself to such a
setup, it's certainly "possible" to do it. But that doesn't change the fact
that unless you're planning on a helm installation it's often cheaper to
just buy two used laptops instead.

* Bill Kearney wrote, On 3/24/2007 10:42 AM:
Sealed??? How does that work? The only way it can run fanless is
with good ventilation.

Sure you can, several of the newer home theatre types of PCs use extended
heat sinks to dissipate the heat from their CPU, video and I/O chipsets. So
while that particular case and motherboard might not lend itself to such a
setup, it's certainly "possible" to do it. But that doesn't change the fact
that unless you're planning on a helm installation it's often cheaper to
just buy two used laptops instead.

Yes, I should have been more specific that what I meant by "it" was
the Via board in a mini chassis. There are certainly a number of ways
to remove heat, but I don't think they fall within the design
parameters of this system.

I have followed a company that builds embedded supercomputers for use
in military and other applications. While in the beginning the
engineering challenges were digital hardware, and then software
design, the problem evolved into a mechanical problem, namely, how do
you remove heat from the system.