Let L denote the discrete Dirac operator generated in ?2 (N,C2) by the
non-selfadjoint difference operators of first order (an+1y(2)n+1 + bny(2)n
+ pny(1)n = ?y(1)n, an-1y(1)n-1 + bny(1)n + qny(2)n = ?y(2)n, n ? N,
(0.1) with boundary condition Xp k=0 (y(2)1?k + y(1)0 ?k)?k=0, (0.2)
where (an), (bn), (pn) and (qn), n ? N are complex sequences, ?i; ?i ? C, i =
0, 1, 2,..., p and ? is a eigenparameter. We discuss the spectral
properties of L and we investigate the properties of the spectrum and the
principal vectors corresponding to the spectral singularities of L, if ??
n=1 |n|(|1-an| + |1+bn| + |pn| + |qn|) < ? holds.