Re: Homebrew STG card

[Jon Elson <jmelson-at-artsci.wustl.edu>]

stratton-at-mdc.net wrote:

> > With regards to the Xilinx FPGA chips, I have access to computers that
> > can program them if people want.  I would need a bit of help though.  I
> > also have Xilinx on my personal computer, but don't have the hardware.
>
> This borders on tangential, but there are types of FPGA's that use
> RAM based configuration cells that must be intitialized after each
> power on.  Usually this is done with a little 8-pin serial EEPROM, but
> the configuration data can be sent from a computer as well.

The Xilinx XC95xx family have EEPROM cells distributed throughout
the chip, and it is programmed by a very simple serial interface, called
the JTAG bus.  It would be VERY easy to program these chips through
a parallel port.  Xilinx in fact sells a parallel port adapter that isn't
much
more than a couple of driver chips.

Jon