P112 question - what can you run that uses 1MB of RAM?

Actually no. To do that you need to be able to process the data rapidly enough to lay down dots as the drum rotates. The key thing for Laser printing (or any page printer) is the bit image need to exist before the paper moves or at least be preprocessed so that the raster image processor can fill a "band buffer" . The Video dot rate for a DEC LN01 (xerox 12PPM engine) was about 7mhz. The early character only version use a 12mhz 80186 with 8089 to keep up, The system IO to the host was handled by the 8089. Oddly the 8PPM LN03 Ricoh based engine was not much slower on the video clock. In the late 80s there were two lasers often those that were band buffer and generally limited to text and limited graphics and a higher priced version that had enough ram to buffer the page so the image could be composed before the paper was even moved.