Handheld PC!!!

Post by **gannon** » Mon Jan 03, 2005 6:11 am

yeah, just buy a 12VDC atx power supply. Most of them will even run good off of 11V

Epicenter · Post by **Epicenter** » Mon Jan 03, 2005 1:53 pm

Your best bet IS the VIA C3. It emits almost no heat, which means no need to extraneous cooling and noisy fans and so forth. It uses very little power as well. If you MUST have extreme speed in a homemade handheld you're probably a little screwed, because a P4, if an ITX board for one exists, will emit a huge amount of heat to get rid of and suck up power like there's no tomorrow .. an Athlon XP will also use a great deal of power and produce quite a bit of heat (not as much) to get rid of .. and though the Athlon 64 emits only about 35-45w of heat (far less), I don't think any ITX boards support it yet.

As for "a Doom 3 Portable", it's pretty unlikely you'd be able to shoehorn an AGP graphics card of any sizable mass like the GeForce 6xxx series or Radeon series into it. Plus then there's cooling of that to worry about.

So. Your best bet would be the VIA C3 and onboard video, audio, LAN, etc. A wireless ethernet device is only about $20 (get a USB one and just hardware it in), so I don't think it's as expensive as you think it is. Add a low-power consumption notebook hard disk and you're about set.

Despite prior posts in this thread to the contrary, don't try to run your machine on 11v. You'll have massive instability, and run the risk of data loss or other annoying problems. Your supply should be at least 200w really, and provide proper, stable 12v, 5v, 3.3v rails, and they should not wobble around. Batteries .. that won't go over too well, methinks.

Good luck, this could be interesting.

HK-47 · Post by **HK-47** » Mon Jan 03, 2005 1:57 pm

Unidentified Assilant wrote:And for it to be truly portable, I need batteries, how do I get a PC to run from battries, its impossible.

Than how is a laptop powered? Oh yeah, BATTERIES!

Guest · Post by **Guest** » Mon Jan 03, 2005 7:45 pm

Hey
I have been looking into the same thing.. but your telling me that batteries can not run one of these mini itx boards? why is that can you explain?

what about sceens?

SgtBowhack · Post by **SgtBowhack** » Mon Jan 03, 2005 8:06 pm

It can be powered by batteries. Someone just said something silly. With the proper voltage regs, anything can be run off of batteries. If you have a 24v LiIon battery, you can use a pair of 12v regs like this:
input output ground
24v 24v 12v

input output ground
12v 12v 0v

So basically what you're doing here is hooking up the 24v positive voltage to the input of the first reg, and putting the ground of the first reg into the input of the second reg. The difference between output and ground is 12v, so the first reg will think 12v is ground. This is fine. You want this. Because now you take that 12v and call it ground. From there you can get -5v by adding a 7v regulator to the lower reg (in other words, +7v becomes your -5), you have -12 already, it's the ground from the battery. And then 17v (using a 5v regulator) becomes your 5v. The problem is finding regulators that can handle the amperage you'll need. But that's the theory behind getting all the voltages... you'll also need 3.3v too probably. Anyway, using a lot of regulators you should be able to get all of your voltages

Most likely what you'll need is some sort of inverter attached to a mini-ITX power supply though

In short, it's not impossible, but it'll be so huge that buying a laptop would be the better option.

Realistically, it is beyond consumer capabilities to produce a laptop-type thing. Something like one of these or these (if they ever come out) might be your best bet- they already are set up for low power and size. I know it's not quite as cool as building your own, but until VIA does something smart and adds a +12v in version of their nano-ITX boards (and why not?) the ability to make your own portable with them is severely limited.

HK-47 · Post by **HK-47** » Mon Jan 03, 2005 8:11 pm

Dont forget oqo! http://www.oqo.com/

someone · Post by **someone** » Mon Jan 03, 2005 8:29 pm

those things are SOOOO slow its not even funny.

HK-47 · Post by **HK-47** » Mon Jan 03, 2005 9:34 pm

Its running at 1 ghz with a 20 gig hard drive and 256 meg of ram... The computer im using now is only a bit better than that.

someone · Post by **someone** » Mon Jan 03, 2005 9:35 pm

no. the processor is clocked fast enought, but it runs slowly is what the review i read said. (if they are to be trusted)

SgtBowhack · Post by **SgtBowhack** » Tue Jan 04, 2005 2:25 am

Well, a 1GHz P3 or Athlon (not even mentioning PowerPC) is gonna run a lot faster than a 1GHz Crusoe or C3. 1GHz Crusoe processors sometimes get whomped by like, 400MHz Intel and AMD processors in certain apps... and the C3 is usually safe to be compared to processors that run about half the speed too by the big three.
A 1GHz Crusoe is fine for web browsing and all that fun stuff, but for playing games it licks nuts. I don't think it's a native x86 platform even... it uses some virtual machine software crapola.
In any case, yeah. My computer is 450MHz right now but I'd say it probably whomps some of these tiny PCs in certain apps because it has a nice speedy architecture and robust chipset and all that good stuff.

jellywerker · Post by **jellywerker** » Tue Jan 04, 2005 4:16 pm

have you seen those little 1.8in hdd's? they go up to 40gb I think, low power cunsumption too.

someone · Post by **someone** » Tue Jan 04, 2005 7:13 pm

jellywerker wrote:have you seen those little 1.8in hdd's? they go up to 40gb I think, low power cunsumption too.

actually toshiba is building an 80GB one and they already make a 60GB

Post by **Black Six** » Tue Jan 04, 2005 8:14 pm

someone wrote:
jellywerker wrote:have you seen those little 1.8in hdd's? they go up to 40gb I think, low power cunsumption too.
actually toshiba is building an 80GB one and they already make a 60GB

Yep, that's what's inside the iPod. They have an even smaller one for the mini.

SgtBowhack · Post by **SgtBowhack** » Tue Jan 04, 2005 9:19 pm

I thought the Minis just used some internal CF or some such? They've got CF up to like 8GB now.

Post by **Black Six** » Tue Jan 04, 2005 9:24 pm

I'm pretty sure it's just a small hard drive. Knowing Apple they'd sell the mini for $400 if it was solid-state, for that fact alone. Grrr.
Personally I'm holding out for the iPDA or iPad or whatever they're gonna call it.