Laptops at sea?

[Pericles]

Does anyone know the commands to invert the screen image on a laptop please?

Pericles

[slomotion]

seafox -

What rebel heart was talking about was your external power supply. You don't need a spare one of these unless the one you rely on fails. And, external power supplies for laptops, printers, LCD flat panels, etc. are prone to failure - especially in a hot humid marine environment. The handiest spare to have is a universal unit with multiple output jacks and adjustable voltage settings. Obviously, this is not very important if you rely exclusively on DC/DC conversion to run/charge your laptop and other external source devices. I have no experience with DC/DC converter failure rates - but the ideal cruising vessel has a spare for everything (until it becomes overloaded).

The answer to your other question is basically, yes. Regardless of how you divide the volt*amp equation, if the product is 120W, you will draw 10 amps from a 12 volt bank plus any additional power required for associated conversion devices.

BTW - you have a rather hungry laptop. My IBM/Lenovo Thinkpad is 3.25 amps @ 20 volts.

[W32PAMELA]

Seafox, 6.93 amps@19vdc is the maximum rating of your power brick, not what your laptop draws. You probably draw less than 1/2 that which is still well above what you could get with a more efficient processor. A DC/DC converter won't be more efficient than the AC/Dc power brick but they can produce much less RFI.

Pericles, When you say "invert" do you mean rotate the screen image? If so you can usually get to this option by right clicking on the desktop. It depends on the graphics adapter in your laptop.

Bob Stewart
IslandTime PC

[hellosailor]

Seafox-
Power cords, like big AC power cords, are pretty robust. But for some laptops with proprietary connections on the power cord...It is better to have a spare cord AND supply, whether that's AC or AC/DC. Cords break, get lost, get twisted.
One PITA from Lenovo (Thinkpad, ex-IBM) is that every unit comes with an AC-only power adapter. Oh, they MAKE a perfectly good AC/DC unit that can plug into either AC or DC to be used as a direct DC/DC power adapter, but you can only order it as an accessory, not a replacement for the stock AC adapter.
So that's one more reason to buy a direct DC/DC supply. If it fails, you can always use the old AC supply plugged into an inverter.

Jef-
"How do you actually "navigate" with your GPS plotter or laptop? What tasks do you typically do?" In cruising mode I don't. My GPS is an older GPS, no plotting, no intention to upgrade anytime real soon. Well, it will draw a plot but just on a screen with range circles--no mapping. My laptop is just fine, but I prefer not to be bothered by electronics and would rather it was stowed away in a safe dry place. I'm fine with some paper charts--even printouts from the nav software sometimes will do.
Then again...the first time I took a boat up through the East River and Hellgate was well after midnight with no charts at all, just knowing "that's where the big boats go". < g >

OTOH if I'm racing, I'll lay in course lines on the nav software to approximate "best course" from point to point. And let the GPS position run on top of that, and make sure there's enough battery to feed the thing all the time because the GPS plot won't be there if the computer shuts down.

Along the way I'll look at how the course would better be run, ignoring the route plot in favor of the reality of best wind/current and adjusting for real time, etc. Still, seeing all the information in real time helps to figure things out ahead of time, and especially helps to see if we've been steering "this way" and the current has been putting us "that way" making a course correction advisable. (Not just from moment to moment using the GPS display, but looking at the plot to see things like "Gee, every time we get three miles out, the current hits us, let's make sure we tack before we hit that line next time".

Paper is nice, but sometimes you can play "what if" and factor in more information on the computer. You can also graphically overlay tide/current information, to see what's going to be hitting you hours down the course, depending on where you are. Sometimes that affects the choice of "stay in or go further out?"

I suppose somewhere out there is newer better software that factors in all these things and just issues advisories and orders, too.<G>

[seafox]

Thank you for all the answers above.

Seafox, 6.93 amps@19vdc is the maximum rating of your power brick, not what your laptop draws.

the 6.3amp 120watts is on the plate on my Asus 2500h. It is a real hungry pc.

BTW - you have a rather hungry laptop. My IBM/Lenovo Thinkpad is 3.25 amps @ 20 volts.

Yep. All the new ones use heaps less. I want to upgrade but the new ones dont support my pmca sierra wireless aircard. I need a usb aircard. The telecom contract I am in expires in March and I can then resign and get a usb aircard on the new contract. If I do it now I will have to pay retail for the card.
Bit of a pain really as I would love one of those laptops with 9 cell bats and processors that last 4 hours. I will also buy a spare batt when I upgrade.
My current battery only lasts 45 mins. It was a new battery 6 months ago.
Even when the laptop was new I barely got over an hour out of it.

[hellosailor]

"the 6.3amp 120watts is on the plate on my Asus 2500h. It is a real hungry pc." Yes it is. It is also a classic example of a laptop built with a DESKTOP CPU, against Intel's direct orders. They literally told the builders not to use that chip in laptops because of the power consumption, to wait for the mobile versions.

But...you know how marketers are. Wait? And lose sales?! Hell no, rush a faster machine out the door. Lots of vendors did it.

[Pblais]

I will also buy a spare batt when I upgrade.
My current battery only lasts 45 mins. It was a new battery 6 months ago. Even when the laptop was new I barely got over an hour out of it.

Lithium Ion batteries die from the day they are born. Buying a spare now won't pay off down the road.

[Weyalan]

I tend to buy cheap as chips laptops from eBay and throw them out when they break. My latest one is a Toshiba Tecra that has survived 2 years so far and is still going fine (it cost $AUD120 which is about $US100, including a licensed copy of XP).

I also purchased a little gizmo on eBay for about $10 that converts 12v DC to 13,14, 15, 16, 17, 18, 19 & 20v DC. It plugs into a cigarette lighter socket at the nav station and the Toshiba doesn't seem to mind.

[seafox]

Lithium Ion batteries die from the day they are born. Buying a spare now won't pay off down the road.

It will get me two lots of battery time on the boat for the life of the two batteries. For $120 that seems good to me.

[Alan Wheeler]

including a licensed copy of XP).

How the heck do you get a licensed copy of XP for $120, let alone the laptop included. Me smells a fish and it ain't fresh.

[hellosailor]

Wheels-
"a licensed copy of XP for $120,"
No foul needed. The version of XP that ships (legally) with any computer is an OEM-version that is tied to that hardware. It cannot, and often will not, install and run on anything else. It looks for a BIOS string identifying the motherboard, and won't run on much else. It is also non-upgradeable and non-transferable, in most cases and most countries.
So, what is it worth? A whole lot less than a retail version. That's the way MS wants the game to be played.

[seafox]

Alan,
I think he means he is buying 2nd hand ones on Ebay. You can get some pretty cheap laptops on trademe 2nd hand too.

[2divers]

After reading the replies so far, I guess I'm in for it!

To be able to move aboard, I need to be able to take my job with me (which I can fortunately). That job requires a computer with some pretty decent processing power, ram and video card. (I'm a Civil Engineer and I need to run Autocad for those who know what that program is.)

Now my last laptop is 6+ years old and still going strong. The new one (Dell) will come with me and will have a pretty good power draw (being an XPS M1710). But hey, I figure I can put up with an increased power draw if it pays the bills and I can stay longer where ever I happen to be cruising at.

Now I did get the 12V auto/air extra power cord, mostly so I could have a little more variety of places to use it. I will be purchasing a pelican case for it before we move aboard (business expense).

Sounds like I need to make sure I have the cash available and the software on disk to replace the laptop if needed every couple of years. But hey, it's a business expense at that time.

[Inkwell]

I use a mac ibook with GPSNavx software. No problems with coastal sailing. Keep it out of the rain. I keep it on the chart table with a strap to secure it. The battery life is about 4-5 hours, then recharge with an inverter while underway. The software keep a GPS track and the computer sleeps when not needed. Never had a problem.

[seafox]

Hi Inkwell, how long does your laptop take to charge on the inverter?