I have an old Laserwriter II NT. Like it a lot. But now I have a Compaq Presario, with a HP deskjet 3650.
Question: Can I somehow connect the Laserwriter to the Compaq so that I can print documents? It was so much nicer having tons of toner available and being able to print large quantities so easily.

If you have XP, the drivers are already included in the OS:
http://support.microsoft.com/?kbid=293360

I am talking about physically connecting the printer to the computer. It's a whole different type of connection. Can it be done, I am wondering?

Hmmm... you may this: http://www.interconnect-solutions.com/32787-tv3p.html (Bi-Directional Serial (RS-232)/Parallel Converter )

I think it can be done, however, most things can be done given enough time and money. Having said that here are some suggestions on what to try:
- You would need to create a printer in windows that prints to the serial interface (usb or a db-9 or db-25 on the back of the box) or the parallel interface with a parallel to serial converter like what's mentioned above.)
- Next, you need to build a cable that converts the serial connection from RS-232 to RS-422 (what the printer will speak.) See this link for how to do that: http://francis.courtois.free.fr/jc1/serial/main.html - a lot of good info there.

The physical conversion is probably the biggest pain.

Your other option is to find a motherboard from a version of the laserwriter family that supported ethernet or RS-232 from a 25 pin connector like the Laserwriter IIg and replace it. Look here for one example: http://macnstuff.com/

I hope this helps.