If you want to use PDO_OCI and get proper russian windows-1251 codepage, just add charset=CL8MSWIN1251 to your DSN.
$dbc = new PDO('oci:dbname=192.168.10.145/orcl;charset=CL8MSWIN1251', 'username', 'password');
Ðlso setting apache/registry/system environment variable NLS_LANG to RUSSIAN_CIS.CL8MSWIN1251 may helps you.
If you get the error: TNS: could not resolve service name
Remember that the PDO wants to use the default client, which will only use the tnsnames.ora in %ORACLE_HOME%\network\admin. Check that file and make sure your service is defined in there.
BTW, there is a bug with pdo_oci8 with 9i - don't use it. Make sure you just use pdo_oci.dll.