  The $D$-dimensional $(\beta, \beta')$-two-parameter deformed algebra
introduced by Kempf is generalized to a Lorentz-covariant algebra describing a
($D+1$)-dimensional quantized space-time. In the D=3 and $\beta=0$ case, the
latter reproduces Snyder algebra. The deformed Poincar\'e transformations
leaving the algebra invariant are identified. It is shown that there exists a
nonzero minimal uncertainty in position (minimal length). The Dirac oscillator
in a 1+1-dimensional space-time described by such an algebra is studied in the
case where $\beta'=0$. Extending supersymmetric quantum mechanical and
shape-invariance methods to energy-dependent Hamiltonians provides exact
bound-state energies and wavefunctions. Physically acceptable states exist for
$\beta < 1/(m^2 c^2)$. A new interesting outcome is that, in contrast with the
conventional Dirac oscillator, the energy spectrum is bounded.
