Old enough that it isn't supported with Mac OS X Mountain Lion 10.8.x

The speed quality and performance of new $100 printers or printer-scanner-copier-fax make a new one a good value.

You can run Windows 7 or 8 on your Mac or in a VM if you want as well.

http://h10025.www1.hp.com/ewfrf/wc/document?cc=us&lc=en&dlc=en&docname=c01856359

https://www.macupdate.com/find/mac/hp%20printer

https://www.google.com/#sclient=psy-ab&q=hp+deskjet+6122+driver+mac+os+x&oq=hp+d eskjet+6122+driver+mac

Direct you to the proper forum for MacBook :

MacBook Series Forums

https://discussions.apple.com/community/notebooks?view=discussions

http://www.apple.com/support/macbookpro

Mac OS X Forum

https://discussions.apple.com/community/mac_os?view=discussions

This forum deals with a desktop/tower 65lb Mac Pro

http://www.apple.com/support/macpro

Driver for HP Destjet 6122 for MAc is here:

http://h10025.www1.hp.com/ewfrf/wc/softwareCategory?cc=us&lc=en&dlc=en&product=8 3027

Users guides as well.

HP Deskjet 6122 Color Inkjet Printer Troubleshooting

HP Printers Not Supported in Mac OS X v10.6 Snow Leopard, OS X v10.7 Lion, or OS X v10.8 Mountain Lion

Introduction

If you use any of these Mac versions on your computer, consider upgrading to a newer printer that supports Snow Leopard, Lion, and Mountain Lion. The majority of HP printers on the market support these operating systems. Click here for information on which HP printers support Mountain Lion, Lion, and Snow Leopard.

Installing older HP drivers and software on a Mac running these operating systems might create conflicts.

Included in Snow Leopard are third party Gutenprint drivers that provide basic print functionality. Drivers are also available for Lion and Mountain Lion. Click here to obtain the drivers. Gutenprint is a collection of open source printer software, including PostScript Printer Description files (PPDs), that is part of Mac OS X v10.6. It was formerly known as Gimp-Print. When Mac OS X v10.6 sets up the printer, it tries to locate the PPD file for your printer. If it cannot find the PPD file, you can use the Gutenprint PPD file.

Please note that Gutenprint drivers are not supported by HP or Apple. For more information about printers supported with Gutenprint drivers, click here .