[O] Modify sorting order of agenda (newest scheduled todos first)?

[M]

Hi,

I want to change the sorting order in the agenda (the standard seems to be
that overdue items are sorted by date so that the oldest ones are shown
first) to get the items listed in the following order:

* as a first list:
todos with a deadline today or before today,
sorted by priority (descending), then sorted by due date, starting with
today and the oldest todo at the last position.

* then a blank line with "a customized text" in it

* then as a second list todos scheduled today or before today,
sorted by priority (descending) and then sorted by scheduled date, but the
newest ones first


e. g.

DEADLINE TODO [#A] re-configure org-mode
DEADLINE TODO [#B] read org-mode manual
in -3d   TODO [#B] do this
in -10d  TODO [#B] do that
a customized text
SCHEDULED TODO [#A] learn LISP
SCHEDULED TODO [#B] understand Emacs
SCHED.1x  TODO [#A] What I should have done yesterday
SCHED.1x  TODO [#B] What I might have done yesterday
SCHED.2x  TODO [#A] What I should have done the day before yesterday
...
SCHED.20x TODO [#A] What I should have done 20 days ago
SCHED.30x TODO [#A] What I should have done a month ago

IF there are examples for such a configuration of the agenda, please send me
a link. I did not find anything in the manual, but maybe I've overlooked it.

Kind regars

Martin