Part 1 Tech Specs 1 of 3 Tech Specs 2 of 3

So here we are, the last of the foundation articles in the series. So far we have covered a lot of ground and this time we have a little more to go before we put it into practice. No, there will not be a quiz at the end of the article, but there will be something of a practice exercise for you. First let’s finish the ports and abbreviations.

USB – Universal Serial Bus is the de facto connection these days for peripherals. You can find keyboards, mice, speakers, wi-fi cards, printers and more that will connect through the USB. There are two versions of the protocol USB 1.0 and 2.0. Version 2 is much faster and is the standard these days.

You can find it everywhere from MP3 players to video game consoles now. You can stack or daisy-chain USB devices to one controller and connect up to 127 of them including the bus or connection on the computer itself. Generally a computer will have more than one controller allowing for more devices than you will ever need at once. There are multiple plug formats called A and B. A is the standard oblong shaped plug while B is the almost square plug with two corners cut diagonally (see image). USB2.0 is capable of transferring up to 480Mbit/s or about 60 Megabytes per second.

Firewire– Firewire (by Apple) is also known as IEEE 1394 or i.Link (by Sony) is another serial bus interface used for high speed data transfer. The connection is usually a small rectangular 4-pin plug or a 6-pin version that is larger and longer with one rounded end (see image). There are two speeds 400 and 800 (with a 9-pin connector). The first is capable of 100, 200 or 400 Mbit/s data transfer while the latter is capable of up to 786 Mbit/s and is compatible with the FW400 6-pin connector. This adapter can be used for ad-hoc networking and allow for fast data transmission for computer/computer or computer/device networks.

Parallel – Commonly called the printer port, centronics port or IEEE 1284. This port is rapidly disappearing from use thanks to USB. It is technically a legacy port, a port that is completely or partly obsolete. The parallel port consisted of a 25 pin connector called DB-25 (see image) and is often listed as LPT in most operating systems. Parallel ports were bi-direction meaning they could transfer data in both directions. Due to the large number of wires used for connecting devices the cables were often hard to work with.

Serial – Serial communications ports or RS-232 ports consist of a DE-9 connection (see image) with 9 pins. They connected to a UART (universal asynchronous receiver/transmitter) that translated the data and managed all communications. It takes bytes and changes them into bit streams so that they can be sent as electrical pulses. Serial ports work on bit rates with the larger the rate the more data that can be transferred at one time. Modems commonly are rated in Baud Rates which are nearly the same as bits per second or bit rate. Rates range from 110 to 2,764,800 bits/second. Serial ports are also becoming legacy ports as USB is replacing them as well. Serial ports required a lot of configuration to work properly and include settings like speed (bit rate), data bits (the number of bits of data), parity (an extra bit used for error detection), stop bits (send to signal the end of a byte), flow control (handshake or transmission protocol. A collection of ‘signs’ for the control of the data flow) as well as IRQ and Base Port address. IRQ being the interrupt request or way for the computer to know where each device is and what data to send to it and base port address being the input/output address assigned to specific service or device. So you can see why they have falling out of favor and being replaced by the plug-and-play USB.

Yes, I know it’s all very technical and confusing which is probably why they are becoming obsolete. The ability to just plug in something and have it install properly and work is a great time-saver and benefit to everyday computing. So let’s take a look at a standard listing for a computer now and put all this jargon and information to use.

Intel Pentium D 3.0ghz, 1GB DDR2 RAM, 250gb SATA HD, 4 USB, 2(x8) & 1(x4) PCI-E, 2 64-bit 133MHz & 1 64-bit 100MHz PCI-X, 6 SATA Ports, 2x RJ45 LAN ports, serial port, parallel port, 6 PCI, 1 ISA, and one AGP 8X/4X/2X slot