HP 2600n - can't print landscape mode?

Unfortunately, you can't have it both ways. All laser printers read an escape code at the start of the print job to tell it which orientation to use. Usually, there is a setting at the printer, which can be overridden by a driver setting.. but you can override both with the data sent as part of the print job... controlled by your software application. If you software is formatting data that would fit best on landscape (like long text lines) and not sending the right command.. the place to fix this is at the software application level. That being said, try setting the printer up to print the first page in portrait and print it out and then set the printer up to landscape mode for the second page and then print it out. This is done through the Print function of whatever software application that you use to print like MS Word, MAC Paint, etc.