in 8-bit video mode, however the data bus has been connected to the wrong pins.
The bus [7:0] has been used rather than [15:8]. Is it possible to get a YCbCr
output on the [7:0] bus so that I do not have to modify the PCB?
Unfortunately the answer to your question is no. 8-bit data can only be fed out
on the pins[15:8]. You will need to modify your PCB.