forums.ps2dev.org

Ok, rather than sit on this info until I had a working prototype,
I decided I am better off sharing all of this so others can look
at it in the mean time. A couple of side problems have stymied me,
as I will explain later.

Essentially, the gist of it is that DEV9 has an RS232 serial port.
In theory, it probably exists on all versions of the Broadband
Adapter, but only the North American one likely has anything
connected to it. Whats connected to it on the NA adaptor ? Well,
the modem of course!

In fact, on the NA adapter, the Modem is wholly on a daughtercard
that snaps onto the main adapter board. It snaps on with an unusual
20-pin (2 rows x 10 pins/row) connector. It is this connecter through
which the RS232 signals transit from DEV9 to the Modem. Just remove
the modem board, and voila! There is a serial port just waiting to
be used! The modem board could in theory be used elsewhere too,
more on that later.

The key to DEV9 serial is figuring out which line is which. There
may not be a datasheet on DEV9, but you can find one on the ASIC
used in the modem daugherboard. Tracing the lines back through
the connecter to the DEV9 gives us what we can use.

I have been able to visually determine the following:
The first seven RS232 lines above would be the ones you can use
to pinout a 9-pin serial cable. I plan on using a CAT5 cable to lead
out of the PS2 unit terminated with a RJ-45 connector. This allows
easy use of RJ45-DB9 converters.

Now, if you really want, you can still make use of that modem board!
Snap a RJ-11 phone jack on one end for a telephone, and a RS232
cable on the other end, and voila! Instant external modem! It probably
could even be powered off the serial line from the host! There are
even pins on the modem ASIC for an external speak (or cellphone
connections for that matter, hunt down the datasheet for the gory
details!).

So how does one use this once it put together ? The quickest way to
give it a spin is if you have a PS2Linux kit, since it already has
serial drivers available for this. You will need to download the serial
modem kernel patch and kernel module from playstation2-linux. The dev9
register addresses are in the source too for building a ps2dev SDK
driver.

The reason I am stymied are twofold:
1. I am bad at soldering. These traces and vias are WAY too close
together. Instead of soldering the board directly, I am going
to try to find compatible connectors. I think I actually found
a back alley shop in Akhihabarra that has a ton of these connectors.
I am going back this weekend.

2. Since I want to see if the non-NA broadband adapter might have
any of these lines traced out, I will need to pop the DEV9
chips off of both kinds of broadband adapters, since the traces
run underneath the chips. I already destroyed my modem board for
the same reason, the only way I could follow things to figure
their functions was to pop off chips and connectors. So in the
mean time, I will have no working broadband adapters, at least,
not a working NA BB adapter. I do have a 3rd BB JPN adapter
without the modem.

I have a co-worker visiting the country next week that I will ask to
bring another NA network adapter. In the meantime I will have hopefully
obtained connectors for a "no solder" (on the PCB boards that is)
method of hooking things up.

If I get any more progress, I will make more updates. We may finally
have an IOP SIO! Well ok, its not the same as a true SIO, but it will
be an SIO thats accessible from both EE and IOP (the PS2Linux drivers
are EE-side drivers), so it would make a great console terminal for
programs on both sides. You would also have a small external modem
in the bargain!

Gorim

gorim wrote: The first seven RS232 lines above would be the ones you can use
to pinout a 9-pin serial cable. I plan on using a CAT5 cable to lead
out of the PS2 unit terminated with a RJ-45 connector. This allows
easy use of RJ45-DB9 converters.

Why use cat5 to get it out? Why not build the db9 directly into the network adapter? Unless yours is wildly different than mine, there is plenty of room for the small bits of wires and it would only take a small bit of time with a dremel tool to make a nice mounting spot for the db9 connector, the internal casing of the network adapter would work great for holding the db9 in place as well... (I've been thinking of mounting a db9 in the network adapter for a while...)

Now, if you really want, you can still make use of that modem board!
Snap a RJ-11 phone jack on one end for a telephone, and a RS232
cable on the other end, and voila! Instant external modem! It probably
could even be powered off the serial line from the host! There are
even pins on the modem ASIC for an external speak (or cellphone
connections for that matter, hunt down the datasheet for the gory
details!).

You could probably leave the modem semi-intact inside the network adapter, and worse case find a fancy enough switch to control if the modem or db9 is connected.

Drakonite wrote: Why use cat5 to get it out? Why not build the db9 directly into the network adapter?

Hey, thats another way to do it! I didn't consider that, but then I am
squeamish about gory surgeries on my hardware. My intent with the CAT5
is that I could route the cable through the then-unused phone jack easily
enough without making physical alterations. Ideally, I could find a
dual RJ-45 socket block to replace the RJ11/RJ45 combo already there.

Drakonite wrote: You could probably leave the modem semi-intact inside the network adapter, and worse case find a fancy enough switch to control if the modem or db9 is connected.

Hmm...not sure about that...the modem sits flush pretty much against
the back. Any mods would not be able to protrue far in. There is a metal
bracket/shield between the modem and the plastic wall of the adapter,
which *could* be removed, but that still wouldn't leave much space.

I think most ppl would not actually use the modem. It is easy to remove,
and easy to put back in. Some might find it more convenient to build
out an external modem than can either still be used with the PS2
(externally) or with other equipment. Once removed, there is mucho
space inside the adapter for other things.

But hey, choice is good. There is a variety of ways people can approach
this once they have the information they need to muck around. :)

Gorim

gorim wrote:There is a metal
bracket/shield between the modem and the plastic wall of the adapter,
which *could* be removed, but that still wouldn't leave much space.

Dremel a hole into the metal shield, thats what I've been planning to do. :)
I've confirmed that, at least on the network adapter I have, there is enough room to add a db9 and a switch (and maybe enough for a homemade sio board if it was cut to size...). (The board on the back doesn't cover the entire adapter)
The tricky, and maybe impossible, part of what I was saying would be rigging a way to switch off the modem enough that it doesn't interfere with the serial port.

Oh well, if anyone gets this setup and the software side ready, I'll probably play around with an interesting hardware hackup for it, but until then I'll just get my EE SIO done and enjoy it :)

Go Dremel go! (I will pass on that with respect to my own, I already
destroyed two adapters beyond repair figuring things out! :(

Actually, switching off the modem may be easier than you might think.
There may be a relevant pin on the Conexant modem ASIC that will
do it. For example, there is a reset line going all the way out to the
connector. If held at a certain state, it might have the effect of shutting
things down (the datasheet will say). There may be other things.

Or...you might want to experiment :) There are speaker lines, AMPS
cell phone lines, even GSM lines (need extra logic to really use them).
Lots of fun things!

I don't have the datasheet for the Conexant modem ASIC on my work
computer, but if you would like me to send it to you later I can. Its
non-trivial to find and download on the net, but if someone wants to
host it and other related information on dev9 serial i/o tricks that would
be great!

Gorim

Just to be clear, it's not DEV9 that has a serial port, but the North American network adapter has a built in serial port. You can easily verify this by looking at a SPEED (the name of the ASIC found on the network adapter) register. It contains bits for each device supported by the ASIC. On my PS2/Linux network adapter, only the HDD and ethernet bits are set.

Again, you can only pull this off with a North American network adapter, the one that includes the modem.

The PS2/Linux SMAP and modem sources are a good place to locate this register and the function bits.