Re: A89: Me distributing roms.
[Prev][Next][Index][Thread]
Re: A89: Me distributing roms.
Miles, one of the things manufacturers do is mess with the numbers.
Hard drive companies do NOT use base two to specify their HD capacity,
likewise telecom companies DO NOT use base two to spec ALL of their line
capacity.
A 3.2GB hard drive is exactly 3,200,000,000 bytes of info. It is NOT
3.2 x 2^30, as one would expect on a computer. This is why, once the
drive is formated, people call the manufacturer and say, "The computer
reports the drive as a 2.98GB HD (2.98 x 2^30), not a 3.2GB!!!
WAHHHHH!"
It is the same way with ethernet. 10baseT runs at EXACTLY 10 million
bits per second, or 10 x 10^6, NOT 10 x 2^20. Why is that, you ask? It
is easier and cheaper to use and purchase crystal oscillators on even
intervals of 10MHz than just about any other frequency. It is the same
with 100baseTX.
Modems are EXACTLY the same way. 56k refers to 56000 bits per second.
It has to do with the baud rate generators in the UART chips that drive
the modems, which, again, are based on nice round frequencies (the
following are all in bits per second, which should not be confused with
BAUD):
150
300
600
1200
2400
4800
9600
19200
38400
76800
115000
There are other bit rates available depending on which UART and clock
you are using, and I suppose you could go to the trouble of basing all
the frequencies completely on base 2, but why? Because you want to sell
a more expensive, less standard product?
Oh, and don't pick apart the fact that I use K and k interchangably, as
well as other prefixes. While there are many who would like a standard
system (K = 10^3, k = 2^10, etc) there is no such international standard
in place (which is why the HD companies can get away with it...)
-Adam
Miles Raymond wrote:
>
> A few things. A 56Kbps modem is not the same as a 5.6KBps modem.
>
> b = bit
> B = byte
> K = kilo
> M = mega
> G = giga
> p = per
> s = second
>
> 8b = 1B
> 1024B = 1KB
> 1024KB = 1MB
> 1024MB = 1GB
>
> 8Kb = 8192b = 1024B = 1KB
> 8Kbps = 1KBps
> 56Kbps = 7KBps
>
> A 1mbit cable line would NOT be 100kilobytes per second, but rather 1024Kbps
> (kilobits per second), or 128KBps (kilobytes per second).
>
> > I may not know how to do anything but hello world in asm but networking I
> do
> > know =]
>
> Maybe you should get to know it a little better then...
>
> -Miles Raymond EML: m_rayman@bigfoot.com
> ICQ: 13217756 IRC: Killer2 AIM: kilier2
> http://www.bigfoot.com/~m_rayman
>
> ----- Original Message -----
> From: "Serial" <Serial@earthlink.net>
> To: <assembly-89@lists.ticalc.org>
> Sent: Thursday, January 13, 2000 8:09 PM
> Subject: RE: A89: Me distributing roms.
>
> > I believe his math is wrong. The OC256 that at&t is laying across the
> > atlantic to connect the 2 continents is a 2 gbit line which would roughly
> be
> > ~200meg/s
> > the quick conversion for (g)(m)(k)bits/s is to just add 2 zero's and
> reduce
> > to a lower letter if nessessary.
> > for example. a 56kbit modem like an x2 is really 5.6 kilobytes max
> > downstream
> > and a 384k/s downstream dsl would be ~38.4 kilobytes /s
> > a 1mbit cable line would be 100kilobytes per second. etc.
> > I may not know how to do anything but hello world in asm but networking I
> do
> > know =]
References: