Computer Learning

[lostcowboy]

Hi Muell, First let me correct a misconception of my own first. There are eight data bits and a stop bit in the (now common) data stream from a modem. So one should multiply by nine. If anyone is interested in Asynchronous Serial Transmission you can look here. http://www.howstuffworks.com/framed.htm?parent=modem.htm&url=http://www-scm.tees.ac.uk/users/a.c...
Note this article talks about the start bit, seven data bits, a parity bit, and a stop bit.

Now Muell, from your reply, I am not sure that you were aware that I was replying to a message that was talking about modem throughput speed testing. Here is the message http://www.investorshub.com/boards/read_msg.asp?message_id=638542 When I read that message I thought that there was some confusion between the kilobytes that the speed test was talking about and the kilobits that these high speed modems, and ISP's like to brag about. Some people were thinking that they're dsl modems were testing out slow, due to the fact that the test said that it was for cable modems. If the test is designed properly it will give good results, no matter the speed of the modem. It looks to me that test is giving accurate results.
Here is the speed test that they were talking about http://www.cable-modem.net/features/oct99/speed.html

Now about the history of computers, I am thinking that we used to use another word for the four bit words. But I can't remember it right now. I think you are talking about the hexadecimal numbering system. http://www.computeruser.com/resources/dictionary/noframes/nf.definition.html?bG9va3VwPTIxNjA=

I never worked with it but did work with the octal numbering system http://www.computeruser.com/resources/dictionary/noframes/nf.definition.html?bG9va3VwPTM0NDE= which used only three bits. And the binary number system of course. http://www.computeruser.com/resources/dictionary/noframes/nf.definition.html?bG9va3VwPTc5NA==

I am not totally sure what you are talking about here.

The two extra bits you are mentioning are included with a data stream of bytes and are there to identify which computer peripheral wants the attention of the microprocessor so the uP knows where to send the reply. They are called the Most Significant bit and the Least significant bit and the spacing between pulses is the identifier.

Unless it is about the hardware interrupts and the hardware ports. Anyway it was not what I was trying to talk about.

One of these days we will have to get together and talk about the old electronics. I got out of the navy in 1992, and that was the last time I got to talking about digital electronics to this depth.

May you have a happy new year, and lets pray that next year will be better than this year was.