[Linux-parport] OxPCIe952 EPP
elson at pico-systems.com
Tue Apr 12 17:58:56 PDT 2016
I saw your post on linux-parport from Dec 2014 about the
Oxford 952 chip.
I have been selling motion control boards using the parallel
port in EPP mode since 2001.
I have been using roughly the same code to drive the
parallel port all that time, from
ISA multi-I/O chips through PCI to PCIe. I have only tried
a couple PCIe parports.
I just discovered the same problem you had with reading at
the PC end. I did use a logic analyzer to observe the
problem. To read, bit 5 of the ctrl reg is set to 1, and
then the parport chip will not produce a pulse
on the DATASTB/ pin when the EPP data port register is read
with an INB instruction.
I don't know how Oxford Semi. could have screwed up this
badly! They have been making PCI multi-I/O chips for at
least a decade and they all worked. I used to recommend
SIIG PCI parallel ports as the most reliable, and they all
used Oxford chips. As far as I can tell, these PCIe chips
will not work with any printer or scanner that actually uses
I'm amazed that there aren't more people having problems
I found the Syba boards with the NetMos 9900 chip work fine
with my code and my boards.
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