I got this from Hewlett Packard. It is for the 690 series but works very well for the 680 series. Disk 2 of 3. This is a self extracting exe file. Just double click of the file icon to extract.
The following files are found inside the driver download file.
|Hpftrl16.dlz||233.7 KB||30 Jun 1998|
|Hpftbx16.exz||87.7 KB||30 Jun 1998|
|Hpfwin16.dlz||118.1 KB||30 Jun 1998|
|Hpfimg16.dlz||1.0 MB||30 Jun 1998|