Note from bleemer2 - I
didn't write this, I'm not even sure who did. I don't know how to use it,
or any software to use with it. Could this be a key to ripping GDroms?
I don't know. If you have any more info on software and what can be done
Email
me Thanks
This page describes how to build an adaptor for
the Dreamcast serial port that will allow you to connect it to any computer
using a standard 9-pin DSUB connector. The main component is a MAX voltage
converter, since the Dreamcast serial port uses CMOS (3V) voltage levels,
whereas normal RS232 uses +/-12V levels. If you are having trouble finding
the MAX chip, you may want to consider ordering it from ELFA.
This serial adaptor has been designed,
built and tested by me. It works prefectly for me, but I will not
be held responsible if it fries your DC, your computer, and/or your hair.
Also, please note that you will probably only find this interface usable
if you're running your own software on the DC. I don't know of any "standard"
software that communicates anything of interrest to a computer on the serial
port.
Here's what you need:
One DC<->NeoGeo link cable (you can get it at David
Console Shop for example)
One MAX3222CPN line driver / voltage converter
Four 0.1µF capacitors
One 9-pin DSUB connector (male)
Some bits of insulated wire
Optionally: A pair of 6-pin connectors (DIN/whatever)
The reason I've used the DC<->NeoGeo
link cable is that it provides the right type of connector for the DC serial
port, removing the need to solder directly on the DC. It also contains
a full set of line drivers, reducing the risk of damaging the DC if you
make a mistake. So what I did was to get the NeoGeo link cable, and cut
the NeoGeo-end in half. This leaves a set of colored wires hanging that
can easily be soldered as needed. You can either connect the cables directly
to the MAX, or do as I did and solder on a connector of your choice (i
used a DIN6 connector), allowing you to easily separate the voltage converter,
and reconnect the NeoGeo connector cable end should the need arise. A third
alternative is to remove the NeoGeo cable altogether, and connect directly
to the CON1 connector on the link cable circuit board. This is the method
pictured on the blueprint below, but the cable colours are also provided,
if you want to use another option. Below is a picture of the DIN6 variant
(the thing just behind the right of the DC is a VGA box, and not part of
the serial adaptor):
Now, the first thing you have to do
is get a +3.3V feed. The CON1 connector (and therefore the NeoGeo cable)
has all the neccessary signals, except the voltage needed to drive the
MAX chip. Fortunately, there are several easily accessable locations on
the NeoGeo link cable circuit board where you can tap off the +3.3V. Open
the black box and locate the diode marked D1 (it's right in the center
of the right half of the board, surrounded by resistors and transistors).
Just to the left of this diode, there should be a small hole. This is a
through hole for the +3.3V (it passes from the bottom side of the board
to the top side). This is an ideal spot to attach a wire, just put it thouth
the hole and solder it at the opposite side. Then make a small hole in
the side of the plastic box and you can extract the other end of the wire.
In the picture above, you can see a thin green wire coming out of the box
in this way. Note that this wire is the reason I used 6-pin DIN connectors,
and not 5-pin.
When you have the +3.3V and the CON1
wires, all that remains is to solder everything together.
To connect the adaptor to a computer,
you should use a crossed cable (0-modem). To connect a modem (no idea why
you should want to do that, but hey... :) use a straight cable. The adaptor
has RTS/CTS, so you can use hardware handshaking. The MAX3222CPN is guaranteed
to handle bitrates up to 120kbps.
