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New Rev 4 Board |
A newer version (Rev 4) of
this circuit board is available. Rev 4 includes a faster CPU,
more memory, more I/O and an optional LCD. We recommend you use
Rev 4 for new projects. Even though this older board is no longer
available, we are keeping these old pages on-line for reference
to assist people who purchased or build the older version.
Now Available
The rev 4 board is available.
See this page for ordering details.
The information below, about the prototype, is out of date.
The Rev 3 Prototype Version (obsolete)
The information in this section is obsolete. The
Rev 3 version described here was replaced with Rev 4.
The new board design is finished, but there will be a delay
until they have been manufactured and constructed. Here is a
photo of the prototype (the actual boards will be professionally
manufactured boards, with green solder mask, silk screen, and
plate-through holes). This is just a prototype, to verify that
there are no routing errors and that all the parts fit well.
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Figure 1: New Board Design, Prototype Only. Actual boards will feature green solder mask, silk screen, and plate-though holes. |
This new board changes the AM28F256 (which is now obsolete and
probably won't ever be available anymore) to a SST39F512. Other
modern flash rom chips should also work. The new flash chip
does not require 12 volts. A five volt regulator was added,
with room for a heatsink, which is not necessary for the board, but may
be needed if power hungry circuits are added in the prototype
pad area. This allows the board to run on unregulated power, and
a diode is included to protect against reverse wiring.
The new board also includes more power supply decoupling capacitors,
and a better arrangement of the components so that they fit well.
Like the older board, high resolution images of the artwork, and a
full schematic will be provided for free on this website.
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