  We use current cosmic microwave background data to constrain cosmological
parameters. The results are presented as confidence regions in the
($\Omega$--$H_o$) -- plane for both open and flat geometries, and are based on
a $\chi^2$ minimization to the power spectrum. Although such an approach does
not strictly apply to power spectrum estimates, the results should nonetheless
be indicative. We find that purely open, low--$\Omega$ models are strongly
disfavored, due to the position of the ``Doppler Peak'' at high $l$; flat
models are less strongly constrained. The parameter space explored is the
largest to date, covering $\Omega$, $H_o$, $n$, $Q$ and $\Omega_B h^2$.
