  In this paper, we relate the feedback canonical form \textbf{FNCF} of
differential-algebraic control systems (DACSs) with the famous Morse canonical
form \textbf{MCF} of ordinary differential equation control systems (ODECSs).
First, a procedure called an explicitation (with driving variables) is proposed
to connect the two above categories of control systems by attaching to a DACS a
class of ODECSs with two kinds of inputs (the original control input $u$ and a
vector of driving variables $v$). Then, we show that any ODECS with two kinds
of inputs can be transformed into its extended \textbf{MCF} via two
intermediate forms: the extended Morse triangular form and the extended Morse
normal form. Next, we illustrate that the \textbf{FNCF} of a DACS and the
extended \textbf{MCF} of the explicitation system have a perfect one-to-one
correspondence. At last, an algorithm is proposed to transform a given DACS
into its \textbf{FBCF} via the explicitation procedure and a numerical example
is given to show the efficiency of the proposed algorithm.
