                  100 IRE(1/2)

An IRE is a unit used in the measurement of
composite video signals. Its name is derived from
the initials of the #YInstitute of Radio Engineers#Y.

A value of 100 IRE was originally defined to be
the range from black to white in a video signal.

A value of 0 IRE corresponds to the zero voltage
value during the blanking period. The sync pulse
is normally 40 IRE below the zero value, so, peak
to peak, an all white signal should be equal to
140 IRE.

                                    #C(cont...)#C
                  100 IRE(2/2)

The reason IRE is a relative measurement (percent)
is because a video signal may be any amplitude.

You can use the R and L triggers to change between
100 IRE to 0 IRE in steps of 10 IRE.

The #CDreamcast#C is slightly above the 713.4 #YmV#Y white
but you can toggle between the #CDreamcast#C 0-800 #YmV#Y
values and simulated 0-714.3 #YmV#Y ranges with #GY#G.

Press #GX#G to for 10, 5, 2 and 1 IRE steps.

With #GA#G you can change the range to 100 and 140 IRE
in 5 IRE steps.
