README.fbcalc


You may need to adjust the values if they
do not fall on the correct boundaries (see the table in the manual).
Here are the parameters:

fbcalc width height <A> <D> <E> <B> <C> <S> <P> <Q>

Where

<A> - horizontal period in usec
<D> - horizontal active area in usec
<E> - horizontal front porch in usec
<B> - horizontal pulse width in usec
<C> - horizontal back porch in usec
<S> - vertical front porch in msec
<P> - vertical pulse width in msec
<Q> - vertical back porch in msec

Plug in the values and fbcalc will give you the fbconfig command to
use, for example on a 640X480 display:

% fbcalc 640 480 31.778 26.058 .318 3.813 1.589 .064 .064 .793
fbconfig -n ? 640 480 24.5606 8 94 39 2 2 25

You now need to do several things. Replace the "?" with a new
configuration mode number, and make sure that the values in the
fbconfig line comply with the requirements of the table in the manual
(~ page 157). For example: 94 (hsync), 39 (hback) do not comply because
they are not divisible by 4.  Also add whatever flags your monitor
requires. For example, Sun monitors require composite syncing ("c"
flag). The "r" flag indicates read only, so only use it AFTER you
finished tweeking the numbers.


Regards,


Tadpole Customer Support