WA: cheap SBC?

Hi,

I'm about to start a new project, and am looking for an SBC to use for 
prototyping. I need something with a VGA output and an ethernet interface.  
A CF-type drive or HDD as well. I'd prefer a powerpc board, but it's not a 
requirement. If anyone knows where I could acquire something like this 
at a decent price (<$1k. maybe the $2-500 range), please let me know. 

Thanks,

--buddy

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> prototyping. I need something with a VGA output and an ethernet interface.  
> A CF-type drive or HDD as well. I'd prefer a powerpc board, but it's not a 
> requirement. If anyone knows where I could acquire something like this 
> at a decent price (<$1k. maybe the $2-500 range), please let me know. 

PPC boards (that I know of) are just outside your range, starting
around $650. But there is NO problem at all sourcing an x86-based
board with those peripherals. What physical size, etc?

Lewin A.R.W. Edwards <larwe@larwe.com> wrote:
: 
: PPC boards (that I know of) are just outside your range, starting
: around $650. But there is NO problem at all sourcing an x86-based
: board with those peripherals. What physical size, etc?

Looking for something small - handheld size. It'll eventually be a small 
appliance type device.  

--buddy

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> Looking for something small - handheld size. It'll eventually be a small 
> appliance type device.  

Oh. That's vastly more difficult. Especially since you'll probably want 
it to be battery-powered. I'd look at XScale PDA development systems. 
<http://www.intrinsyc.com/products/create.asp>, 
<http://www.applieddata.net/products_bitsy.asp> maybe.

Lewin A.R.W. Edwards <larwe@larwe.com> wrote:
:> Looking for something small - handheld size. It'll eventually be a small 
:> appliance type device.  
: 
: Oh. That's vastly more difficult. Especially since you'll probably want 
: it to be battery-powered. I'd look at XScale PDA development systems. 

Actually no. It'll be wall powered.  I'm just looking for something that's 
smaller than, say 8x5.

--buddy

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> Actually no. It'll be wall powered.  I'm just looking for something that's 
> smaller than, say 8x5.

Oh! In that case, very easy. Look at www.icpamerica.com and 
www.advantech.com, both of them have a range of SBCs in the same 
footprint as a 3.5" disk drive, both of them will sell you small 
quantities. Different options according to your performance 
requirements, starting at 486-class up to much faster systems (the 
fastest I've worked with in this form factor is 800MHz Via C3; 667MHz 
and 533MHz Eden variants also available). Many are fanless. All of them 
have at least your requirements (and more).

Prices start a bit under $200. The boards I've used the most are the 
WAFER-5820 (ICP) and PCM-5820 (Advantech), which are both 300MHz Geode 
and are just about $230 each, give or take. Single +5V rail, your PSU 
should be rated 5A to allow for a hard disk.

My desktop development unit is a PCM-5820 built up in a housing that 
once contained a 3.5" magneto-optical drive. Overall it's about the size 
of a regular 5.25" CD-ROM/DVD drive, including power supply, hard disk 
and slimline (laptop) CD-ROM drive. If necessary I could swap in the 
667MHz Via board without increasing the overall system size.

"Lewin A.R.W. Edwards" wrote:
> 
> > Actually no. It'll be wall powered.  I'm just looking for something that's
> > smaller than, say 8x5.
> 
> Oh! In that case, very easy. Look at www.icpamerica.com and
> www.advantech.com, both of them have a range of SBCs in the same
> footprint as a 3.5" disk drive, both of them will sell you small
> quantities. Different options according to your performance
> requirements, starting at 486-class up to much faster systems (the
> fastest I've worked with in this form factor is 800MHz Via C3; 667MHz
> and 533MHz Eden variants also available). Many are fanless. All of them
> have at least your requirements (and more).
> 
> Prices start a bit under $200. The boards I've used the most are the
> WAFER-5820 (ICP) and PCM-5820 (Advantech), which are both 300MHz Geode
> and are just about $230 each, give or take. Single +5V rail, your PSU
> should be rated 5A to allow for a hard disk.
> 
> My desktop development unit is a PCM-5820 built up in a housing that
> once contained a 3.5" magneto-optical drive. Overall it's about the size
> of a regular 5.25" CD-ROM/DVD drive, including power supply, hard disk
> and slimline (laptop) CD-ROM drive. If necessary I could swap in the
> 667MHz Via board without increasing the overall system size.

Just remember that "fanless" is a relative term.  If you put even a VIA
677MHz CPU in a small box and don't have ventilation, it can easily over
heat.  I seem to recall that they use about ~10 Watts when cranking. 
That plus a hard drive can make a small box pretty hot.  

My VIA 800 MHz came with a CPU fan.  I tried running it with the fan
unplugged and it got up to 60C or so.  If I had stopped the PS fan it
would have gotten much worse.  That was in a uATX tower.  In a small
case the temperature would have been a problem for sure.

> Just remember that "fanless" is a relative term.  If you put even a VIA
> 677MHz CPU in a small box and don't have ventilation, it can easily over

Via doesn't recommend fanless operation for anything faster than the 
533MHz Eden, and even that requires a pretty large passive heatsink. The 
C3 is AFAIK explicitly not intended for passive cooling. (I'm trying to 
avoid the word fanless, because Peltiers are a possibility).

The 667MHz Via chip gets fiercely hot unless you have either active 
cooling or a very massive heatsink (not a standard product, in the 
main). Advantech's Via-based boards have a very large, thick, heavy 
custom heatsink that covers one entire face of the board and contacts 
all the major chips. They get warmer than you'd think - 40-45 Celsius, 
especially if you're giving the video chip a serious workout.

A couple of vendors have supplied us with sample boards with 667MHz C3 
and a large (2" tall) passive heatsink. These have been barely 
acceptable in free air. I would not install one in a housing that did 
not have some kind of force-fed air.

Geode runs a lot cooler. We haven't encountered any situation where 
active cooling is necessary. Low-profile heatsinks are the norm.

"Lewin A.R.W. Edwards" wrote:
> 
> Geode runs a lot cooler. We haven't encountered any situation where
> active cooling is necessary. Low-profile heatsinks are the norm.

I am curious, how low profile?  I have seen Geode PC/104 boards.  Would
this fit inside a stack (0.435" clear space above board)?  I expect
not.  I guess they have to use these on the top of the stack.  

I will be selecting a CPU to go with some other PC/104 boards and would
like to get one that is not overly hot, but still has reasonable
performance (and all the bells and whistles).

>>Geode runs a lot cooler. We haven't encountered any situation where
>>active cooling is necessary. Low-profile heatsinks are the norm.
> 
> I am curious, how low profile?  I have seen Geode PC/104 boards.  Would
> this fit inside a stack (0.435" clear space above board)?  I expect

The Advantech PCM-5820 meets that requirement. They use a heatsink that 
sits approx 0.28" proud of the top of the PCB. It's a little hard to get 
my micrometer in there to measure it accurately, but that's a reasonably 
close approximation. Anyway, it's considerably shorter than the PC/104 
connector. The tallest parts on this board are the DB9 serial connector, 
the RJ45 Ethernet jack, and the mini-DIN PS/2 connector. I can send you 
a photo to illustrate this if you want. The PC/104 connector is on the 
CPU (component) side of the board, and it is not a "through" connector. 
The reverse side of the board has CompactFlash and SODIMM SDRAM sockets.

ICP's board uses a larger custom heatsink panel with a separate 486-size 
heatsin glued on top. e-valuetech (BCM) boards use an off-the-shelf 
heatsink that sits about 0.75" off the top of the PCB. You couldn't 
stack anything on top of these.

The vendor photos of these devices usually show them nude, so you can 
read the pretty numbers on the chips but you can't guess what heatsink 
will ship on the thing. I hate that. It makes it impossible to gauge 
what will fit where.