gEDA-user: Single board computer - was Printing your artwork

[Darrell Harmon <mail@xxxxxxxxxxxx>]

Dave McGuire wrote:

> On Aug 9, 2005, at 12:51 PM, Darrell Harmon wrote:
>
> > 100x100mm SBC running GNU/Linux:
> > http://dlharmon.com/sbc.html
>
>
>   Hey, speaking of this...This looks like a great design; I'm 
> interested in building one.  Have you had a chance to correct the few 
> small issues with your 20040720 etch rev?
>
>            -Dave
>
> --
> Dave McGuire             "I wonder what 'Error Code 1' means. That's
> Cape Coral, FL            what it said when it started smoking."  
> -Jonathan Patschke
The errata are not too bad to fix.  In fact I just used some blue wires 
which can be seen in the pictures.  It would only take a few hours to 
fix the files.  There are a few other issues with the design that I 
don't like.  The first is the 2mm pitch connectors.  They are bad for 
signal integrity, and they also like to wick solder into the receptacle 
side ruining the connector.  I also don't like the PQFP package FPGA 
(Signal integrity).  These are the main reasons I don't just simply fix 
the bugs (2 Mirrored SOT23-5 footprints, mirrored crystal oscillator).  
I have been getting a lot of interest in this board lately, and am 
considering a complete redesign keeping compatibility with DSPCARD.  I 
would remove the DSP and NET2272 from the DSPCARD and replace it with an 
AT91RM9200, 64MB SDRAM (32 bits wide this time) and 256MB of NAND 
flash.  The only thing lost would be the CF slot, and that could be put 
on the daughtercard if desired.  Between USB flash drives and the 256MB 
NAND flash, the CF should not really be necessary.  The size would be 
about 80x80mm.  One other thing that would be lost would be the ability 
to assemble it entirely with a soldering iron due to the BGA FPGA.

I have 2 other projects going right now, so time is tight. I have the 
time to get the schematics how I want them and lay out the board, but I 
don't really have the time that would be necessary to improve the 
bootloader and Linux drivers. The bootloader is currently a hack that 
really needs some time spent on it.  A NAND flash driver for Linux also 
needs to be written.  If someone would be willing to handle the software 
side, I would handle the board.

This is really offtopic for geda-user, so please respond to the dlhsbc 
google group which I created long ago, but have never used.  We can 
discuss where this project should go there:
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send an email to dlhsbc-subscribe@xxxxxxxxxxxxxxxx

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--
Darrell Harmon
100x100mm SBC running GNU/Linux:
http://dlharmon.com/sbc.html