Punmaster has right that LM1881 has not standard h-sync signal but v-sync ist standard. I looked on the datasheet of the LM1881. On Pin1 the LM1881 output is c-sync (composite sync). Some displays cannot extract h-sync from the c-sync signal. But we can extract h-sync from v-sync and c-sync with a logic circuit.
RGBCV ---> RGBHV
CVH (csync,vsync,hsync TTL-Level)
h-sync has to be high if c-sync high and v-sync low
Now, if we use 7400 (four NAND) we may get h-sync (I dont know if the 7400 is fast enough).
- From LM1881 put c-sync and v-sync to the first NAND.
- The output of the first NAND and c-sync to the second NAND.
- Put the output of the second NAND to the third NAND (to invert the signal).
- The second NAND and the third NAND as intverter then build a logical AND.
at the end of the site for the circuit.
The LM1881 and 7400 are easy to get in many countries by private purchase.
This may be the solution to get hsync and vsync without the internal sync signals of the XBOX.
I am not sure but I think some very old Sun and Apple monitors need the c-sync instead of h-sync.
Excuse my poor english.