1. Team 4 Project 1 Presentation Mapping Parallel Ports to LPT’s & USB Host Controller Interfaces Tom, Jen, Curtis, Ashley, Scott

2. Mapping Parallel Ports to LPTs

3. What is a LPT port?  LPT (Line Print Terminal) is the common parallel port interface on a computer that connects the printer to the computer.  More commonly used in legacy systems

4. Mapping

5. Select Printer Type

6. Types of Parallel Ports  Unidirectional – Computer sends data to printer  Bidirectional- Printer and computer communicate  Enhanced Parallel Port (EPP)- Like bidirectional but with increased performance  Extended Capabilities- Came out shortly after EPP. Includes data compression for better throughput  IEEE 1284- Ensured compatibility and optimum performance with almost any parallel peripheral

7. USB Host Controller Interfaces

8. USB Host Control Interfaces  One of the original intentions of USB was to reduce the amount of cabling at the back of your PC.  USB uses tiered star topology like 10BaseT Ethernet, requires a hub, adds expense, cables, and boxes, but now devices have built-in hubs like keyboards & monitors  Benefits: monitored power to each device, both high and low speed devices can be supported, up to 127 devices can be connected on one USB bus with the ability to add more port/host.

9. USB Host Control Interfaces  USB 1.1 - 2 host controller interface specifications - UHCI (Universal Host Controller Interface) burden on software companies & Open Host Controller Interface (OHCI) which puts burden on hardware.  USB 2.0 - EHCI (Enhanced Host Controller Interface) one interface standard means 1 driver  USB uses 4 shielded wires - 2 for power, 2 are a twisted pair, it uses NRZI (Non Return to Zero Invert)

10. USB Host Control Interfaces  Dynamically loadable and unloadable drivers - uses Product ID/Vendor ID combinations to load appropriate driver, fee for VID, but standards organization provide extra VID for non-commercial  USB supports control, interrupt, bulk and isochronous transfers.

11. Questions?