The Microline 3320 9-pin printer driver is a software program that allows your computer to communicate with your Microline 3320 printer. The driver allows you to send print jobs to your printer, as well as configure various printer settings.

To download the Microline 3320 9-pin printer driver, you can visit the OKI website. On the OKI website, select the "Support" tab and then click on "Drivers & Utilities". Next, select the "Dot Matrix Printers" category and then click on the "Microline 3320" link. On the Microline 3320 page, scroll down to the "Drivers" section and click on the "Download" button next to the 9-pin printer driver.

Once you have downloaded the 9-pin printer driver, you will need to install it on your computer. To install the driver, double-click on the downloaded file and follow the on-screen instructions.

After the driver is installed, you can configure your printer settings by opening the "Printers and Faxes" window (in Windows XP) or the "Devices and Printers" window (in Windows 7 or later). Right-click on the Microline 3320 printer icon and select "Properties". In the "Properties" window, you can configure various printer settings, such as paper size, print quality, and duplex printing.

Here are the steps on how to install the Microline 3320 9-pin printer driver:

1. Download the 9-pin printer driver from the OKI website.
2. Double-click on the downloaded file.
3. Follow the on-screen instructions to install the driver.
4. Open the "Printers and Faxes" window (in Windows XP) or the "Devices and Printers" window (in Windows 7 or later).
5. Right-click on the Microline 3320 printer icon and select "Properties".
6. Configure your printer settings in the "Properties" window.

I hope this helps!