Your printer has to be enabled with Adobe Postscript technology - of the three printers you mention I would suggest that the HP1220C is the most likely. It would have to be the HP1220C/ps model.
It looks encouraging, because you say that the instructions took you to where Postscript should be - it could be shown just as PS level.
You could try downloading the postscript drivers to update the postscript capabilities - hopefully you are on XP as I don't think it will work on Vista
Good luck in your project