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WA: cheap SBC?

Started by Buddy Smith January 23, 2004
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.