Originally posted by: Ymmy
wow, so basically it's close to impossible to build a laptop
No it's not. It's just expensive.
I built one of those breifcase thingies, too. But I sucked at it, and it sucked.
Right now my idea is to build a machine out of a Mini-itx board.
I want to design it to last as long as possible on batteries, so here is my design:
Laptop harddrive.
MII6000 Mini-itx motherboard, with the 600mhz cpu.
It has a daughtercard for PCMCIA cards and flash cards. It also has a optional LVDS-based plugin for a daughterboard to support certian laptop-style LCD displays.
It has USB 2.0 and optional firewire.
Trouble is:
1. Laptop displays suck. They have no smarts built into them, and need a special controller that has scanlines and stuff like that to controll the LCD display. These are embedded into laptop vid cards or motherboards and are useless for anything else. They also require inverter (dc-ac) cards to light them up.
This is expensive, and has limited options. Via LVDS-01 module only support 8 different types of displays out of hundreds that are aviable, and those are only used in certain laptops. Those laptops also have different displays used in the same models that are incompatable.
Desktop-style LCD displays use to much power.
2. The Eden 600mhz cpu is slow. It's about equal to a 400 celeron in cpu power. It uses very little in the way of watts, but...
3. The motherboard and other componates aren't so nice. Together going full force a motherboard + 600mhz cpu + ram + IDE device uses close to 26 watts. Laptops use less then 20watts for "real" notebooks, (not the desktop replacement type). I want to get 10 hours of usable battery life out of it. Nimh battery pack can do that, but will weigh close to or over 2 pounds and extra weight sucks. Using a normal Laptop battery you'll get about a hour and a half out of it.
4. Price, total around 500-600 for the complete package.
You can go and buy a 700 dollar laptop and a extra 100 bucks on a battery pack and get 10x the performance.
Plus there is no garrentee that it will realy work. I could solder something wrong or spend a hundred bucks on the wrong display and then I would be screwed.
If you want a do-it-yourself setup, check out the "Desknote" series of laptops from ECS. These are cheap laptops that you buy and it will take desktop CPU's and memory, among other things. You can find these cheap, but they have no internal battery. External one is optional, but costs, and only lasts around a hour.
But they are truly portable desktop computer. But they are no laptop or notebooks.