THE IMPRESSIVE PARTS

PAPERFEED MECHANISM
A roller picks a piece of paper from the input tray an d passes it to an anti-skew, heavy-friction roller. From there, it passes an aligning roller, and then a metering roller. It then goes through the EP engine, where it gets the image impressed onto it. From there, it goes through to the fusing hot roller. Finally, it heads through rollers that escort the end product to the exit bin.

PAPER TRAYS
Think carefully of all the types of paper you might need your printer to handle. If capacity is important, check the Roll Call on page 168 for maximum paper-capacity ratings.

ELECTROPHOTOGRAPHIC ENGINE
The EP engine receives the bit map from the RIP and, using a low-power laser, transfers the image by coating the photoconductor drum with toner. It then transfers that image onto paper.

LCD PANEL
Before you buy a printer, test-drive the user interface that monitors and controls print jobs. Software programs that you install on a PC are increasingly replacing printers' LCD me nus.

RASTER-IMAGE PROCESSOR
The RIP comprises a BIOS, an emulator, and a band-building system. The BIOS receives input from an incoming port and buffers that data, transmitting it at the highest transfer rate that it and the processor can sustain. The emulator scans the data and determines its PDL (page-description language), parses it, and then renders a full-page bit map. The band-building system quickly creates a series of bands, which it then hands off to the EP engine.

INTERFACES
The more interface options a printer has, the better. Parallel ports should be high-speed and bidirectional, with support for the IEEE 1284 standard. SCSI connectors should be SCSI-2, preferably fast and wide. For a network printer, look for fast Ethernet, LocalTalk, and/or Token Ring. You might need an SNMP-compliant interface, but be wary of anything proprietary. Good network printers can receive data from all ports simultaneously; look for "multiprotocol, multi tasking" models.