Okay, now that I've got the mailing list going, let's see how we can
collaborate. By the way, I'm going to assume that Connectix is
listening and/or watching, so let's NOT have any discussion of
disassembling their software. Reverse-engineering is legal in spite
of any shrink-wrap terms prohibiting it, so it's okay to look at the
outside of the boxes.
I've got a web page at http://www.crynwr.com/qcpc with everything I
know right now. Does anyone know anything more than that? The basic
architecture of the device seems to be a Macintosh Quickcam connected
to a Microchip PIC processor embedded in the connector. Has anyone
probed the pins to see where the serial data is carried? I've got a
logic analyzer connected to the pins of the parallel port. The
parallel port has the ability to generate an interrupt to the system.
I don't think they use the capability. I think that the system and
camera interaction is fully handshaked. That is, the system sends
commands, and waits for data. The camera sends its data and indicates
that the data is there. When the system is driving the camera, it
runs all the time, and never does any kind of I/O wait. This has
significant implications for a multitasking system like Linux
Oh, by the way, there are at least two modes of operation here: dumb
parallel port, and EPP parallel port. An EPP parallel port acts like
an 8-bit I/O port. It generates a read/write strobe whenever the data
port is accessed. For the dumb parallel port, the system has to
generate its own strobe signals. For the highest possible speed in
dumb mode, it's best to use each edge as its own strobe. I haven't
checked to see if that's what it does.
It's going to be the easiest to learn how the box interacts on a
machine with an EPP parallel port, because you don't need to figure
out how the dumb handshaking is done.
Anyone have anything to contribute?
-russ <firstname.lastname@example.org> http://www.crynwr.com/~nelson
Crynwr Software | Crynwr Software sells packet driver support | PGP ok
11 Grant St. | +1 315 268 1925 (9201 FAX) | This isn't rocket science.
Potsdam, NY 13676 | Or if it is, we're getting better at rockets. -lwall