Friday, October 26, 2012
Sunday, October 21, 2012
Modem: a device that converts between analog and digital signals.
When I first became interested in how the computer works, modems were very fascinating.
I had gathered tidbits of info on how the signals are changed from Analog to Digital and then back again. The following is basically what I understood the process to be:
Digital signals, which are used by computers, are made up of separate units, usually represented by a series of 1's and 0's. Analog signals vary continuously; an example of an analog signal is a sound wave.
Modems are often used to enable computers to communicate with each other across telephone lines.
A modem converts the digital signals of the sending computer to analog signals that can be transmitted through telephone lines. When the signal reaches its destination, another modem reconstructs the original digital signal, which is processed by the receiving computer.
If both modems can transmit data to each other simultaneously, the modems are operating in full duplex mode; if only one modem can transmit at a time, the modems are operating in half duplex mode.
To convert a digital signal to an analog one, the modem generates a carrier wave and modulates it according to the digital signal.
The process of receiving the analog signal and converting it back to a digital signal is called demodulation. The word "modem" is a contraction of its two basic functions: modulation and demodulation.
Dennis C. Hayes and Dale Heatherington invented the PC modem in 1977, establishing the critical technology that allowed today's online and Internet industries to emerge and grow.
1978 -- Dennis C. Hayes and partner Dale
Heatherington, working on Hayes’ dining room table, develop first
personal-computer modem and formed a company.
1985 -- Hayes annual sales hit $120 million as
popularity of home computers grows.
1988 -- Hayes and first wife Melita divorce after
six years of marriage.
1994 -- Hayes Microcomputer files for Chapter 11
bankruptcy reorganization.
1996 -- Company emerges from Chapter 11.
1997 -- Company merges with Access Beyond of
Gaithersburg, Md.
1998 -- Hayes Corp. files for Chapter 11.
1999 -- January 6, Hayes shuts down Its
operations.
Hayes-Compatible, in computer science,
an adjective used to describe a modem that responds to the same set of commands
as a modem manufactured by Hayes Microcomputer Products, originators of the de
facto standard for microcomputer modems.
The 56K modem was invented by Dr. Brent Townshend in 1996.
I remember when the 56k modem came out. I was using a 28,800 dial up, upgraded from a 14,400. I thought the upgrade would take me to the speed of sound, but the 56,600 had disadvantages to the new 56k. I opted for the K (for Karen).
I had gathered tidbits of info on how the signals are changed from Analog to Digital and then back again. The following is basically what I understood the process to be:
Digital signals, which are used by computers, are made up of separate units, usually represented by a series of 1's and 0's. Analog signals vary continuously; an example of an analog signal is a sound wave.
Modems are often used to enable computers to communicate with each other across telephone lines.
A modem converts the digital signals of the sending computer to analog signals that can be transmitted through telephone lines. When the signal reaches its destination, another modem reconstructs the original digital signal, which is processed by the receiving computer.
If both modems can transmit data to each other simultaneously, the modems are operating in full duplex mode; if only one modem can transmit at a time, the modems are operating in half duplex mode.
To convert a digital signal to an analog one, the modem generates a carrier wave and modulates it according to the digital signal.
The process of receiving the analog signal and converting it back to a digital signal is called demodulation. The word "modem" is a contraction of its two basic functions: modulation and demodulation.
Dennis C. Hayes and Dale Heatherington invented the PC modem in 1977, establishing the critical technology that allowed today's online and Internet industries to emerge and grow.
They sold the first Hayes modem products to
computer hobbyists in April of 1977 and founded D.C. Hayes Associates, Inc., the
company known today as Hayes Corp., in January of 1978. Hayes quality and
innovation resulted in performance enhancements and cost reductions that led the
industry in the conversion from leased line modems to intelligent dial modems -
the PC Modem.
I always had a Hayes Compatible Modem. They may have been a little cheaper. This probably explains why the Hayes company went out of business in 1999:
TIMELINE:
The 56K modem was invented by Dr. Brent Townshend in 1996.
I remember when the 56k modem came out. I was using a 28,800 dial up, upgraded from a 14,400. I thought the upgrade would take me to the speed of sound, but the 56,600 had disadvantages to the new 56k. I opted for the K (for Karen).
Monday, October 8, 2012
In the beginning...
It was about 1988 when a friend of mine lent me his Commodore 128 Computer with cassette tape for storage. I read a short handbook on programming, I think it was BASIC. I was amused with programming music. I wrote the code for Mary Had A Little Lamb and Twinkle Twinkle Little Star. My fascination beset me and I continued to fill my brain with data!
In 1989 my husband and I bought the kids (then, 6 and 11) an Epson Equity1+. It had a whomping huge 20 MB hard drive and 128k RAM. We also bought an Epson top-of-the-line DOT MATRIX printer with continuous feed paper!
The computer age had arrived and we didn't want the kids to be left behind. In those first few years, I don't remember the kids taking to the computer very much, maybe it was because I was always on it.
Word Perfect and Harvard Graphics were two of my favorite programs. Space Quest III was my favorite game. It was about the time Leisure Suit Larry was becoming popular. I never cared much for Larry, Roger Wilco was my man. I liked space travel.
In 1989 my husband and I bought the kids (then, 6 and 11) an Epson Equity1+. It had a whomping huge 20 MB hard drive and 128k RAM. We also bought an Epson top-of-the-line DOT MATRIX printer with continuous feed paper!
The computer age had arrived and we didn't want the kids to be left behind. In those first few years, I don't remember the kids taking to the computer very much, maybe it was because I was always on it.
Word Perfect and Harvard Graphics were two of my favorite programs. Space Quest III was my favorite game. It was about the time Leisure Suit Larry was becoming popular. I never cared much for Larry, Roger Wilco was my man. I liked space travel.
Thursday, October 4, 2012
My first entry for Nikki's awesome class
So, I hear about Skype, Magic Jack Plus,
and other voip concepts.
My goodness, the communication possibilities seem endless. You can see and talk around the world.
My cousin was studying in France and she would talk to her Nicaraguan cousins using the Magic Jack I gave her. She even had voicemail with it.
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