Questions about HP laptops

miwise · 10-08-2006, 12:37 PM

Hi, I am interested in building a car computer (been wanting to do so for about 5 years but never had the guts to start one, been observing this sight for quite some years now). I have a few questions about the hardware I have:

I have a couple of old P2 and P3 laptops that I'd like to use (broken screens, need ram). The p3 is 450 mhz and the p2 is 350 mhz. Would either of these or both of these run both navigation and play mp3/dvds well? I was thinking of a windows 2000 professional setup since it doesn't need as much ram as windows xp. I'm no software engineer, but I am capable of running my own wires and whatnot (try to tap into my cars existing wiring. . .1996 lexus sc400). The tape deck crapped out on me and now I must resort to fm modulator to input my ipod. I've looked at many aftermarket systems, but i don't like how most of them stick out or how gaps are left either. Custom car computer seems logical to me. I've read about startup times and whatnot. . .using a flash drive, cdrom, etc to start windows98 from. My main concern is getting the thing up and running within about 20 or 30 seconds from key turn to music playing.

I've read about the opus power supplies and whatnot, but my laptop already has a good enough power supply. Next question is how do I get the automatic startup and shutdown to work? Here's what I was thinking, tell me if I'm wrong:

The laptop has a battery, so wire the power straight into the ignition wire in the car so that the laptop gets no power when the car is off. Windows will then take over and turn the power to the laptop off based on the setting I specify in the power management (control panel). (tell me if my theory is flawed).

The problem is with engaging the laptop. I want it to turn on automatically when the car is on...how do I do this? Is it as simple as shorting two wires or what?

v8 scimitar · 10-08-2006, 04:24 PM

you say you have been reading here for years but you seem to have missed a hell of a lot of information.
Your laptop isnt going to handle DVD or even video very well its just too slow. GPS probably but your going to have to get some ram in there.
Start up shutdown on a laptop, an opus or any power supply the same as that just isnt going to work as they are ATX power supplies. The battery idea will work but your going to have to open the case up and solder connections onto the power switch of the laptop. You will then either have to use a manual switch or build a circuit to pulse on these connection. Have a search there is a circuit in here somewhere to do it. Alternatively you can make a fake UPS again search for the circuit. Old laptops might be the cheap solution but they are far from the best and for your furst time round will complicate things a lot.

miwise · 10-08-2006, 04:59 PM

There's so much information, it is overwhelming. I have been looking into (off and on) over the last 5 or so years. Just as a past time to try and figure out how I could integrate something like this in my car. I thought that the laptop would be the best solution for me, but I am starting to rethink this hypothesis. Also, I have forgotten most of the information I read on here. i used to have the schematic on how to build a startup and shutdown controller from scratch, but I misplaced it. I may wait until next summer to tackle this when school lets out (no more grading papers and such). I didn't want to invest in a super expensive system either, so that pretty much rules out those micro atx boards. I had an empeg that had one of those in it, pretty advanced for its time. I may just try and find a good motherboard and mount everything in the trunk where the cd changer was. I don't want to start it until I have a detailed plan, though. Anyways, thanks for the input.

v8 scimitar · 10-08-2006, 05:55 PM

Finding something like an old 1gig pentium or something like that might be a good way for you to go. It wont take too much power but will still be usable for what your wanting to do. Most important for you by the sounds of it is that it will be cheap to do as well. You don't have to spend vast fortunes to get something usable.

miwise · 10-08-2006, 06:27 PM

Sounds good, will start looking. Hopefully I can use my factory amps and volume attenuator to control the sound. Thanks again.

miwise · 10-09-2006, 09:33 PM

Here's what I'm going to do: I'll use my computer at home that don't use very often (athlon xp 2000+). It should hopefully be powerful enough. I'm probably going to play with the bios settings to get the most reliable setting that produces the least heat and power consumption. . .ie, reduce the cpu speed (and maybe voltage if possible). I would think this should make it run pretty cool together with my fan it has. I used to have some heat problems with it so I installed a cooler master 15000 rpm fan with heat pipe technology and its now pretty stable. Hopefully if I reduce the speed it should remain stable in a hot car environment. Would windows xp or windows 2000 be best with this setup? I plan on using a 40 gigabyte maxtor hard drive, but I also have a few other choices. . .80 gig western digital or 80 gig ibm drive. I really want to choose the one that will be most reliable and least susceptible to heat (I live in louisiana and it gets pretty hot from May to September). I'll plan on tweaking my install so that I get the best startup time by removing anything I can think of and a fresh reinstall. I'm going to look into installing windows 2000 on a compact flash or sd card and hopefully make the installation read only. I'll have to research this, though as i've never attempted anything like this. I really like windows 2000 and xp b/c they are a lot more reliable than 98, even though 98 loads a lot faster.

miwise · 10-09-2006, 09:38 PM

How do I determine the wattage that my system draws?

miwise · 10-09-2006, 10:10 PM

correction, I believe it is maybe a 7500 rpm fan b/c the bios says it runs around 7600 rpm. Keeps it around 40 degrees celcius.

Rafster · 10-09-2006, 10:29 PM

I use a Dell 700 PIII Laptop and it's fast enough for all I have to do...

I only have 256MB or Ram because that's the maximum that the laptop will take. What I would suggest is put as much ram as you can into the laptop (you can check the maximum limit at http://www.crucial.com).

I would also suggest that you use Windows XP, but use a lite version. Look up Tiny XP and you'll be ok I thyink for GPS DVD and MP3.... I was playing DVDs just fine on my PIII 333MHZ with a 2X DVD drive and a 2MB Video card so, I don't see why you shouldn't be able to do the same with a 450MHz....

Peace,

Rafster

miwise · 10-09-2006, 10:38 PM

I actually took it apart and it is a 500 mhz. The max it will take is a 256 sodimm. I ordered it already. My main question if the laptops workout (ideal) is if anyone makes a device that can be hard wired onto it to force it to turn on when the car turns on (and not get confused by the on off on off etc that occurs when starting up or whatever else that might occur). In other words, if the computer is running or on, it shouldn't try to cycle the power switch. This is the only thing that keeps me from choosing the laptop. I'd prefer it since it is smaller and uses a lot less power. I used to use an athlon 750 and was very satisfied with the speed of it, so I think the 500mhz p3 should be close to that. I don't think I can do dvd and gps at the same time, but who would want to. as long as it can do at least one thing at a time. Is there a way to hook a normal size hard drive to its ide port? I wouldn't mind sending it off to have it soldered or whatever (I'm not very good at soldering, unsteady hands). Thanks!

Rafster · 10-09-2006, 10:46 PM

Quote: Originally Posted by miwise

I actually took it apart and it is a 500 mhz. The max it will take is a 256 sodimm. I ordered it already. My main question if the laptops workout (ideal) is if anyone makes a device that can be hard wired onto it to force it to turn on when the car turns on (and not get confused by the on off on off etc that occurs when starting up or whatever else that might occur). In other words, if the computer is running or on, it shouldn't try to cycle the power switch. This is the only thing that keeps me from choosing the laptop. I'd prefer it since it is smaller and uses a lot less power. I used to use an athlon 750 and was very satisfied with the speed of it, so I think the 500mhz p3 should be close to that. I don't think I can do dvd and gps at the same time, but who would want to. as long as it can do at least one thing at a time. Is there a way to hook a normal size hard drive to its ide port? I wouldn't mind sending it off to have it soldered or whatever (I'm not very good at soldering, unsteady hands). Thanks!

I would suggest that you do some searching, there are several things you can do to laptops for "Start up/Shutdown controller" like featuers

Peace,

Rafster

miwise · 10-09-2006, 10:52 PM

will look, thanks!

Rafster · 10-09-2006, 10:53 PM

Quote: Originally Posted by miwise

will look, thanks!

No prob..... the

button is always your friend.....

Peace,

Rafster

turbocad6 · 10-09-2006, 11:17 PM

you CAN use ANY startup/shutdown controller for this, EVEN an atx supply like an opus, or better yet, a carnetix p1900, which will probably even give you the right voltages to run your latop diectly off this....

it's just a matter of hard wiring it... if you can hack the switch, you can make any startup/shutdown controller work....., no problem...

miwise · 10-10-2006, 10:33 AM

carnetix p1900 looks like a viable solution as my laptop requires 18 volts input. Sound perfect. Thanks for the advice. As soon as I get my 120 volt psu to test the laptop in the mail, I'm going to buy one from mp3car.com.

Thanks for the pointers!