Letter 2 - Owning a Personal Computer in Silicon Valley
This was the second article I wrote for ASCII DOS/V
Hello Again from Silicon Valley. Last issue I talked about my work. This issue, I'd like to talk about how I use computers at home.
Owning a Personal Computer in Silicon Valley
In addition to using computers at work, I also like to play with computers at home. (My wife says I sometimes spend too much time on computers. But I think it is better than watching TV!)
One of the benefits of living in Silicon Valley is easy access to the latest computer technology. We don't have anything to rival the grandeur of Tokyo's Akiabara district, but we do have a lot of computer stores with very good prices.
Probably the most famous computer stores in Silicon Valley are the "Fry's Electronics" stores. Each of these stores is decorated in a theme. One store looks like an Egyptian tomb. Another looks like a Wild West (American Cowboy & Indian) town. And the biggest one looks like a giant computer. (The front door has an "Enter" key. The exit door has an "Esc" key. Inside there are huge circuit boards with giant models of computer chips, diodes, capacitors, and resistors. It is silly, but fun.) In addition to selling all kinds of computers, software, and video equipment, Fry's Electronics also sells snack food, magazines, and soft drinks. People joke that it's the only store a computer nerd ever has to visit.
"Fry's Electronics" has good prices, but there are even better deals at some of the smaller computer stores. My current home computer is a 200 MHz Pentium Pro with 64 Mb of RAM and a 4Gb hard disk. One local computer shop here currently sells this kind of system, with everything except a monitor, for around US $2,300.
I am always thinking about adding to my system. (After all, it's cheaper to dream about a new component than to actually buy it. The longer you wait, the lower the price will drop!) The latest thing I bought was a special ultra-quiet power supply and ultra-quiet CPU fan. I bought these so that I can leave my computer on all the time without it making too much noise. I want to leave my computer on all the time so that I can use it as my own world-wide-web server.
At Home with a Cable Modem
At work I spend most of my time working within my company's own local-area-network. But at home, I surf the public Internet. I am lucky, because I can surf using a high-speed cable modem. Cable modems are a new kind of modem that are much faster than regular modems. Regular modems use the phone system's wiring to communicate. In contrast, cable modems use the same cables that transmit cable-TV. The cable modem signal is transmitted on unused cable-TV channels. Because cable-TV uses high-capacity coaxial cable instead of the telephone system's twisted-pair copper wire, it can transmit much more information than telephone wires.
The exact speed of the cable modem varies depending upon the system. Like any other way of accessing the Internet, the speed also depends upon the time of day, the speed of the computer you're talking to, and how many other users are accessing the same site. The cable modem is so fast that the speed of the other computer you're talking to usually becomes the limiting factor. In general, a cable modem is about 10-20 times faster than an analog telephone modem.
My cable modem looks like a 1980s-era regular modem. It is a rectangular gray box, about the size of two VHS Cassette tapes stacked together, with the addition of a large heat sink on top. It has two connectors on it: one for the cable-TV cable, and the other for an Ethernet cable. You hook the ethernet cable to your computer. And you configure your computer as if it were talking to a regular Ethernet LAN. Using Ethernet between the cable modem and the computer means that cable modems are compatible with any computer (PC, Macintosh, or Unix) that has an Ethernet connection. There's no special software drivers or other special interface cards required.
When you use a cable modem, you're connected to the Internet all the time. Unlike a regular telephone modem, or even a high-speed ISDN modem, there's no connection delay when you want to start using the Internet. It's just like using a local area network. In fact, if you are willing to leave your computer turned on all the time, it is possible to host your own web site out of your own home. As I mentioned above, that's something I'd like to do!
Here is a diagram of how a cable modem system works:
Probably the main drawback of cable modems is that you have to buy the service from your local cable-TV company. If you don't have cable-TV in your area, or if your cable-TV company doesn't offer this service, you can't take advantage of it. It requires a lot of money to upgrade an older cable-TV system to support cable modems. So even if cable-TV modems become popular, it may be many years before all cable-TV systems offer cable modems.
A second drawback is that cable modems have a potential security hazard. Like a LAN, all the data sent to or from your cable modem is visible to your immediate neighbors. In a company that's not so bad, since presumably everyone in the company is working together. But with a cable modem, it is important to use encryption software to prevent unscrupulous (or just plain curious) neighbors from listening in on your network conversation. Most other modem technologies, such as regular analog modems, don't suffer from this drawback.
Table of different Modem Technologies
Here is a table comparing different high-speed modem technologies. I put it together from various documents available on the Internet. If you are interested in learning more about high-speed modems, one good site to look at for more information is: http://plainfield.bypass.com/~gzaret/hiband.html
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About the table:
"In" means from the Internet to you. "Out" means from you to the Internet. Speeds are in bits per second. Costs are approximate, and in dollars, for Sunnyvale, CA in January, 1997. Start cost includes hardware, software, and setup charges. Cost per month includes communications and Internet Service Provider charges.
Modem Technology In Out Start per month
Normal Analog 33,000 33,000 $80 $35
1/2 digital 55,000 33,000 $150 $35
One channel ISDN 64,000 64,000 $300 $40
Dual channel ISDN 128,000 128,000 $400 $50
Satellite 400,000* 33,000 $750 $70
ASDL 6,000,000 640,000 $2500 $600
Cable modem 27,000,000* 768,000* $150 $35
"*" means that the bandwidth is shared between all the subscribers using the same service. So if 100 people are using the same cable at the same time, each would only get 1% of the total bandwidth.
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