by Joe Waters

Another great new feature introduced on the PSR-3000 is a USB port that allows you to connect USB devices. There are two USB ports on the back of the keyboard. One is labeled TO HOST and the other is labeled TO DEVICE. You can buy a USB cable to run from your PC to the 3000 and connect to the TO HOST port. You would do this if you wanted to play a midi file on your keyboard and have the sound come out of your PSR-3000. The other port is new, and unique, to the PSR-3000. It allows you to connect one or more USB devices to your PSR and this opens up the storage options enormously. (Note that trident symbol under the words USB. It is the USB standardization mark and found on all USB devices.)

What is USB?

Anyone who has been around computers for more than two or three years will understand what kind of a headache it was to connect devices to your PC. PCs came with a parallel port and one or two serial ports. The printer connected to the parallel port and modems used the serial port. But as new devices appeared, like the zip drive, they, too, wanted to use the parallel port. And then we had things like palm drives and digital cameras that wanted to use that serial port. Devices that needed faster connections came with their own cards, which had to be installed in card slots within the computer's case and configuring the software for these devices was often a major challenge.

The goal of the Universal Serial Bus (USB) was to put an end to all of these headaches by giving PC users a single, standardized, easy-to-use way to connect up to 127 devices to a computer. Just about every peripheral made now comes in a USB version and that includes devices that can read and write to flash memory cards. If you are interested in learning more about how USB ports work, there is an article on this topic at the howstuffworks site.

USB Connections

Connecting a USB device to a computer is simple matter of finding the USB port on your computer and plugging the USB connector into it. On newer computers, one or two USB ports are often located on the front panel of the computer. If the port is on the back of your PC, it is unlikely that you will want to be plugging a device in and out of this port. You can, however, simply get a USB cable and plug that into the back of your PC. The other end can then be used to plug your USB device into your PC. If it is a new device, the operating system auto-detects it and asks for the driver disk. If the device has already been installed, the computer activates it and starts talking to it. USB devices can be connected and disconnected at any time.

Many USB devices come with their own built-in cable, and the cable has an "A" connection on it. This "A" connector, shown here, plugs into your PC or the back of your PSR-3000. A USB device may not have a cable permanently attached. A separate cable would be used with one end plugged into the PC(or PSR) and the other plugged into the USB device. In this case, the device has a socket on it that accepts a USB "B" connector (shown below).

The USB standard uses "A" and "B" connectors to avoid confusion:
- "A" connectors head "upstream" toward the computer.
- "B" connectors head "downstream" and connect to individual devices.
By using different connectors on the upstream and downstream end, it is impossible to ever get confused -- if you connect any USB cable's "B" connector into a device, you know that it will work. Similarly, you can plug any "A" connector into any "A" socket and know that it will work

Running Out of Ports?

Most computers that you buy today come with one or two USB sockets. The PSR-3000 has only one USB "To Device" socket on the back. With so many USB devices on the market today, you could easily run out of sockets very quickly. For example, if you have a new USB printer, a USB scanner, a USB flash memory drive, and a USB network connection, how would you use these all at the same time with only one USB port?. The solution is simple. You can purchase an inexpensive USB hub. The USB standard supports up to 127 devices, and USB hubs are a part of the standard.

A hub typically has four new ports, but may have many more. You plug the hub into your computer, and then plug your devices (or other hubs) into the hub. By chaining hubs together, you can build up dozens of available USB ports on a single computer. A hub can also be used on the PSR-3000 and this would allow you to have both a USB floppy disk drive and a USB flash drive attached if you wanted.

Hubs can be powered or unpowered. The USB standard allows for devices to draw their power from their USB connection. High-power device like a printer or scanner will have, of course, their own power supply. Low-power devices, like mice or digital cameras, can get their power from the bus. The power (up to 500 milliamps at 5 volts) comes from the computer. If you have lots of self-powered devices (like printers and scanners), then your hub does not need to be powered. If you have lots of unpowered devices like flash memory drives, mice, and cameras, you probably need a powered hub. A powered hub has its own transformer and it supplies power to the bus so that the devices do not overload the computer's supply.

You can support multiple device on your PSR-3000 by using a USB hub, but it must be a self-powered hub and the power must be turned on. Only one hub can be attached. The first device you attach will be called USB1. The second device will be called USB2; the third, USB3, on up to USB20. Note that if you attach a flash memory drive and then a floppy disk drive, the flash memory drive would be USB1 and the floppy USB2. But if you disconnect these and then reconnect them again, but plug the floppy in first and then the flash drive, the floppy will now be USB1 and the flash drive USB2. The number assigned depends on the order in which you attach devices. Note that USB devices are hot-swappable, which means you can plug them into the bus and unplug them at any time -- you do not have to power down your PC (or your PSR).

Now, that you understand a bit about USB, the next lesson will revisit the question of how to get information from your PC to that SmartMedia card.