I got a broken xbox off ebay that had an X-Bit chip in it but no external board to plug into USB with so I hacked it up and got it to work!
Looking at the chip with the two plugs labeled Y and B orient the chip so that the plugs are away from you. Y should be on the left, B on the right. Ignore B as it is intended for use with dipswitches but without the board I can't figure it out without risking killing something.
The pin on the far left isn't used. The one to its right is ground (black), then D+ (green), then D- (white), then 5v (red). Simply solder wires from a USB cable using the color scheme to those pins and it'll show up as a DK3200 dev board. The X-Bit software will let you flash it just fine but it had command problems on my ASUS P5N-D mobo. However my old Dell Inspiron 7500 laptop worked just fine, then again it is 9 years old. Your mileage will vary, if it doesn't work try a different USB chipset.
Also the X-Bit software for the 1.5 chips is rather hard to find due to DMS's website being down.
But you can grab it there. Mine was an older chip and the software is readily available on google.