I remember the LaserJet 4000 and the 4550 (color beast, the startup sequence sounded amazing with all those motors and the always-on fans). Worked flawlessly for hundreds of thousands of pages.<p>It had expandable RAM, and you could send files to the print queue inside the printer via LPT or Ethernet, and it did PostScript rendering inside, which was quite convenient when printing lots of stuff (reduced the amount of data you had to send, and no issues with interrupted printing). I guess that&#x27;s why it needed its own processor.