Okay, I don't know a whole lot about computers, or programming, but what I do know will be posted here as time permits. It will
mostly be notes, tips, and links that I think are useful - if for nothing other than to give me a place to look when I forget stuff! - Roger J. Wendell
There are 10 types of people in this world: Those who do know binary and those who don't.
"Despair leads to boredom, electronic games, computer hacking, poetry, and other bad habits."
|Click Here for my UNIX page...|
|Click Here for my PERL page...|
An Energy Efficient Computer
"The energy comsuption of personal computers (PCs) is finally becoming a topic of interest outside the mobile and laptop computing cricles. And it's about time. In the United States alone, computers and information technology equipment account for 2 to 3 percent of our annual electricity consumption, to the tune of US$8 billion. According to the U.S. Energy Information Administration, domestic electricity demand is projected to grow at nearly 1 percent annually, mostly to power computers, electronic equipment, and appliances." - Mike Chin, an Energy Efficient Computer, Home Power Magazine 114, August & September 2006 p. 22
Raspberry Pi 4B with the New Ice Tower Cooler
The Raspberry Pi remains my favorite computer, ever! Not only does it solve the aforementioned energy problem but it's just plain fun to use. The Raspberry Pi is a series of credit card-sized single-board computers developed in the United Kingdom by the Raspberry Pi Foundation with the intention of promoting the teaching of basic computer science in schools and developing countries. The price, at the time of my purchase, was $35.00 USD for the basic board and model. The original Raspberry Pi and Raspberry Pi 2 were manufactured in several board configurations through licensed manufacturing agreements with Newark element14 (Premier Farnell), RS Components and Egoman. The hardware is the same across all manufacturers. I purchased (and experimented with!) my first Raspberry Pi (The Model "B" that you see in the photos below) in early 2014 and continued "upgrading" to 4B in early 2021 when I updated this entry. In short, although not as powerful as a "regular" computer, laptop, or smartphone the Raspberry Pi remains a ton of fun that has also had a lot of practical applications in my personal office space and amateur radio shack.
|Click Here my YouTube video installing a SATA drive into a gaming case...|
Some Computer History:
Concept Home Computer, 1954
IBM System/360 - 1964
Intel co-founder Gordon E. Moore, in a 1965 paper, described a long-term trend in the history of computing hardware where memory and/or computing capacity of integrated circuits doubles approximately every two years. Specifically, the number of transistors that can be placed inexpesnively on an integrated circuit has increased exponentially since 1958. This has continued since the invention of the integrated circuit, in 1958, and is expected to continue another decade beyond my entry here in 2008...
Punch cards (also called Hollerith or IBM cards) were a piece of stiff paper that contained digital information represented by the presence or absence of holes in predefined positions. They were first used in the 19th century for controlling textile looms - we saw something similar while visiting silk looms in India. In the later part of the 20th century punch cards were used for computer inputs, processing, and data storage.
I scanned these examples, at left, from my wife's high school key punch class work in 1975. Of course data entry and key punch, for computers, were well out of use by the time I created this web page in the early 2000s. However, during the early 2000s punched card systems were still in use for certain kinds of voting machines throughout America - a controversy worthy of a whole web page of its own someday...
(No, by "networking" I don't mean job hunting (!) but, rather, two or more computers
connected together and communicating with one another for a common purpose...)
Some network history:
Most people agree that the concept for the first practical network evolved from some now-famous research papers on the complexities of creating a workable network in the 50s. ARPA (Advanced Research Projects Agency) was created in 1958 by President Eisenhower - creator of that other famous transportation network, the Interstate Highway System.
ARPA later became DARPA (Defense Advanced Research Project Agency) which it is know by today and still accessible at www.darpa.mil.
The earliest version of ARPANET successfully interconnected four mainframe computers in late 1969. Initially FTP (File Transfer Protocol) and Telnet (a way to control another mainframe computer from a remote location) were the only types of data transfer available.
By the time the first PCs (Personal Computers) became available, in the early 80s, the idea of networking had been around for well over a decade. However, PC networks were first interconnected in physical groups we now call LANs (Local Area Networks) at a time when mainframes were communicating via ARPANET. By the mid-1980s ARPANET had evolved into the Internet. It wasn't until the mid-1990s that PC network makers developed software that enabled PCs to connect to the Internet. It was at about that time, when commercial operations appeared on the Internet, that it became the "World Wide Web." And, as they say, the rest of the story is history!
OSI Seven Layer Model
OSI Stands for Open Systems Interconnection initiative and is a layered, abstract description of computer network communications protocol. The OSI model, from the top layer to the bottom, is made up of Application, Presentation, Session, Transport, Network, Data Link, and Physical layers. A layer consists of related functions that provides services to the layer above it and receives services from the layer below it.
This all came about because in the early days of networking there were all kinds of networks that were using all kinds of systems and protocols that were unique to themselves. The International Organization for Standardization (ISO) proposed the OSI model that's in use today (or at least at the time I created this page in the mid 2000s!). I think it's important to remember (for those times when we need to think outside the "box") that the OSI Seven Layers are not laws of physics - if anyone ever wants to invent or design a new network protocol they can - and, there are certainly other network architectures out there, even now, that have protocols that don't fit nicely into the seven layer model...
TIA/EIA 568A Standard
TIA/EIA 568B Standard
UTP and RJ-45 Connectors
Although a few networks still use coax cable (RG-58 "Thin" Ethernet, RG-8 "Thick" Ethernet, and RG-62 75 Ohms) the vast majority of networks nowadays (as I write this in the mid 2000s, at least!) use unshielded twisted pair (UTP).
Currently CAT5E and CAT6 are the best you can get and handle bandwidths and throughputs of up to 100 MHz/1,000 Mbps and 200-250 MHz/10,000 Mbps, respectively. Both are connected using RJ-45 connectors (similar but larger than the RJ-11 historically used for telephones) that should be wired to either the 568A or 568B standard (the choice is yours, as long as you stay consistent within your own network!).
To the left are illustrations of how I, myself, like to view RJ-45 for proper wiring. Although I've reversed the images they're still exactly the way the Telecommunications Industry Associations/Electronics Industries Alliance defines the industry standard for correct crimping of four-pair UTP. I've reversed the images because that side of the actual connector has a clearer view of the small, 24 gauge wires for my half century old eyes! The "normal" view you usually have, of an RJ-45 connector, has a bit of extra plastic in the way that is the little locking device that holds the connector firmly in place. A much needed feature except it blocks my view of the tiny wires!
|My Own Technological Experience:|
You will be disappointed to learn that I was never a programmer, software engineer, or even a computer repair person - my interest in computers was similar to my "love" for the telephone in that they're devices that help me accomplish work - not things I wish to work on. Nevertheless, as time went along I found the need to learn a bit more about computing than just using a spreadsheet or word-processor.
In the early 70s, while a high school student in Colorado, I had the good fortune to experiment with a "dumb terminal" connected to a local university's mainframe via telephone lines. Now, three and half decades later, I can't remember for sure if we used a primitive modem (where the telephone handset actually sat inside a padded cradle) or there was a more sophisticated hardwire device. Also, I believe the dumb terminal itself was nothing more than a surplus military teletype machine (similar to the model 28s I later used as a Coast Guard Radioman) - Either way, at the time it all seemed like state-of-the-art equipment and I only wish I had photographed it! Oh, what did I use that high school dumb terminal for? My clearest memory is that I'd punch in a few linear equations to get the teleprinter to display a primitive graph on paper output. I also remember that the system, at the end of the project, would automatically send me a message explaining how much CPU time I had used (in thousandths of a second) and charging a few pennies to my school!
Moving on, in 1982, while trying to finish up my degree, I took an Information Systems course and learned a lot about BASIC. I even wrote a program that allowed two matrixes to be multiplied together - no small feat for a business major!! I believe the college computer we were using, back then, was a VAX mini computer but I'm not sure...
In the early 80s I also learned a lot about the RSX11M operating system for the PDP-11 minicomputers we used for industrial applications at my job. For a time, at that job, we also used a couple of Apple computers for machine control but to this day I don't know why... Anyway, a few years later I became well-versed in MS DOS both on the job and at home. By the late 90s I had HTML pretty well figured out and was creating web pages for myself, some small businesses, and various environmental and non-profit organizations. To this day I still use MS NotePad to create all of my HTML documents - maybe someday I'll learn to use Dreamweaver or other web development tools, but, for now, it's just going to be HTML by memory...
In the early 2000s, as an "old" man in my 40s, I took part (my day job got in the way of completion...) of a UNIX course and began playing around with Linux. By 2005 I was teaching myself PERL, with the help of my son, and decided to create these reference pages 'cuz I started forgetting stuff quicker than I was learning it! In 2008 I took some networking classes, the first part of which was mostly a reminder about a lot of stuff I was already familiar with (Wiring RJ45s, OSI, IEEE, terminators, coax, CAT6 UPT, etc.) in addition to a lot of new stuff about MACs (Media Access Control addresses), frames, CRC (cyclic redundancy check), TCP/IP internet protocol, etc.
So, that's pretty much the extent of my computer experience. However, in defense of myself, I still have a ton of technical expertise in other areas: I have extensive knowledge and experience in RF communications - including antennas, amplifiers, transmission lines and associated equipment. I'm also pretty good with household and industrial electrical circuitry and am somewhat experienced in DC applications that relate to solar and wind applications.
So, there you have it! I hope you didn't come to my website looking for answers to some tough computer problems or even installation questions! Most of what I'll post on my site, as time permits, will be various references, techniques, or simple reminders to keep the handful of computers in my life running smoothly so that I can continue to accomplish work as opposed to just working on computers!
- Roger J. Wendell
Fall, 2005 (edited spring 2008)
A bit o' HTML Code and cmd line stuff:
Here's a circular page refresh:
<META http-equiv="Page-Enter" CONTENT="RevealTrans(Duration=2,Transition=3)">
Here's a fuzzy page refresh:
<META http-equiv="Page-Enter" CONTENT="RevealTrans(Duration=1,Transition=12)">
|In 1998 the Sierra Club's Rocky Mountain Chapter Web Committee was honored with the 1998 Webby Award as the "Expert's Choice" winner for best use of the Internet for advocacy. I received this nice certificate for my work on the Chapter's Outings web pages at that time. Friend and fellow activist Charlie Oriez was the driving force behind the very large and succesful Rocky Mountain Chapter website that was also noted as one of the "100 Top Web Pages of Colorado" by the Rocky Mountain News that year.|
Memory Capacities and Calculations
In March '09 I purchased a 1.5tb drive and was impressed with its storage capacity (as time goes on I'm sure 1.5tb will be considered quite small - but, in early 2009 it was state-of-the-art stuff for home computing!). Anyway, my friend and coworker Gary and I were discussing the different ways memory is accounted for. Here's what Gary had to say:
But unlike RAM which is like rows and columns and will come out exactly at 1KB or 1MB or 1GB or 1TB. Disks are very different, with cylinders, heads and sectors of non-binary (power of 2) sizes. This gets even more twisted because of what they call Zone Bit Recording. Since there's more real estate under an outer diameter track than an inner diameter track the frequency is raised and more sectors are recorded on the outer tracks than the inner tracks. The od to id ratio can be nearly 2:1. The number of zones varies, but it's likely to be 8 or more. You can see the effect of this if you have a disk drive utility and read and write from different areas on the drive and measure throughput."
Here's a little spreadsheet Gary put together about the subject:
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