Here Come the Clouds

Once upon a time, I had a Cathode Ray Terminal (CRT -- similar to old televisions) that was connected to a MODEM (MODulator DEModulator -- a box that converted digital signals to/from analog signals on a phone line) which connected to a "mainframe" (very large -- for those days -- computer). My terminal, an ADM 3A, was a monocolor screen with a keyboard. No local processor, no local storage. When I logged into my account on the mainframe, I had my own set of files and access to any applications that had been installed on the main computer.

Now, with the computing clouds, I can have a computer (possibly without a disk drive/local storage) of, perhaps, limited computing power connected to the Internet which gives access to one or more main computers and multiple storage areas. I can connect via different devices and from different locations and get access to my own set of files and make use of various applications installed on those devices/computers.

It sounds very similar between 1981 and 2012 doesn't it? It certainly does to me. What are the differences that exist and what makes those differences?

The first is access speed. In 1981, connections were slow. A person could type in a set of commands (no Graphical User Interface (GUI)) and expect to receive back sets of words or numbers -- possibly some crude pictures made up of typeable characters. The terminal would allow some movement of the "cursor" (think of the marker from the mouse) after receiving special characters that would be interpreted specially. But, basically, it was for sending and receiving text.

In 2012, expectations of connection speed are FAST or FASTER. This means that the user can use a GUI and can receive back all forms of data including video, music, and multiple windows of information.

The second difference is primarily on the "mainframe" side. Via the Internet, the user has access to many different computers, different environments, and a multitude of applications. Thus, the user can treat the "cloud" environment as their own individual computing setup. Plus, since the computer that one uses usually has its own memory (even without a disk), work can be divided between the local computer/PC and the cloud devices.

From an outside point of view, 1981 and 2012 seem rather similar. The effect of access speed and the Internet's capability of hiding where and what is happening creates a very different experience.

The next blog will go into greater details on the advantages (and disadvantages) of the cloud environment.

New and Future Memory

I've got a few more ideas to talk about, but I thought it best to come through with what I said I would do next.

There are two trends going on with memory (for computers -- there is also some fascinating research going on about human memory) nowadays. The first trend is putting it elsewhere (in the "clouds") and the second trend is to eliminate the mechanical aspects of data storage and access.

I will push off the discussion of clouds to the next blog. We'll concentrate on the second trend.

There are a lot of excellent disk drives at the moment. The manufacturers have increased storage capacity, decreased the time to get to (access) the data, and greatly improved reliability.

Most improvements on disk drives have been associated with data density -- how many bits can be packed into the smallest area. The data density helps both storage capacity and transfer rates (the amount of time that is needed to move data from the storage device to working memory (or vice versa)). Blu-Ray disks work with a higher-frequency laser than do DVDs and DVDs use a higher-frequency laser than Compact Disks (CDs). The higher frequency means that the data density can be higher. Thus, Blu-Ray disks can hold more data than DVDs and DVDs more than CDs.

Further improvements are being made on materials, optics (the part that actually reads optical disks such as Blu-Ray), Wikipedia is a great source for more on specific formats and improvements.

What do these disks have in common? They have to move. In order to read (or write) the data, the reader ("sensor") must be over the datum. Usually, this means spinning the disk while the reader stays in the same place. Some magnetic hard disks have speeds exceeding 7800 revolutions per minute. However, movement means something to move it with and mechanical devices just will not work forever no matter how great the quality and design.

We now have many different electronic items -- phones, cameras, tablets, toys, and so forth that make use of non-moving memory. There are a lot of different categories for this, so lets just call them "flash" memory. In this case, there are still lots of data to access -- but the access method is built into the design of the memory device. Let's take a game cartridge as a simple example. The cartridge will contain data which can be addressed. It also has leads (usually copper) that connect to the game player. The game player makes use of these leads to address, and transfe,r the data. No physical movement (except for connecting the cartridge to the game player) is required. Another common example is a "memory card" which is inserted into a camera. Some printers allow photos to be directly printed from that memory card (taking the card out of the camera and inserting it into the printer).

Direct access memory devices are (currently) more expensive that disk drives -- but the cost continues to decrease as they become more popular and it is my opinion that they will take over for local storage eventually. Personally, I am still hoping for holographic cube storage as was seen in Star Trek.

Let it be so.

Old Memory

Yes, I walked a mile through the snow to school. But, that really wasn't such a big deal (still isn't). I lived in a small town where walking was quite safe and there were sidewalks in front of almost every house.

But, in terms of computers, I started programming when the main input media was punched cards (I saved a lot of them for shopping lists for a number of years). When I started college, I worked on a "personal" computer that used punched tape along with toggle switches on the main processing unit. The main storage devices for the larger computers (IBM 360 at first, migrating to IBM 370s before I left) were huge disk drives.

However, memory (as mentioned before) can be categorized into temporary working memory and long-term storage memory. Working memory at that time was core memory -- little magnets that looked like donuts and linked together with copper wires. We still call it core memory after the memory of those days. Most working memory of today is now located within DIMMs (Dual In-line Memory Modules -- see Wikipedia) or, for older systems, SIMMs.

The memory modules have great advantages over old core -- speed, size, and capacity. They also generate much less heat which is both an energy savings as well as a design improvement.

Storage memory is another category which has moved from technology to technology. The first was paper (well, the VERY first was probably clay tablets or chiseled stone). For people, writing or drawing stored the data/information and reading brought it back. It's kind of funny, but efforts have been quite intense over the past twenty years to allow computers to do the same thing that humans have done -- to be able to directly make use of printed text and images.

For early computer systems, it was not possible for the computers to directly use text or drawings. They needed a way to detect a contrast between spaces. This usually meant holes. The holes allowed light, or a mechanical probe, to move through the paper. The areas without holes blocked the light or probe. In this way, the computer could read the "bits" (present/non-present, on/off, 1/0) and save it.

Next came magnetic methods. These were primarily on discs and tapes. The technology of disk drive design has developed enormously over the past 30 years such that a portable disk can hold the same data that a room of luggable, replaceable disks did way back when.

Currently, we are moving farther and farther along to making working memory cost-effective to use as storage memory -- which will lead to the next post on "New and future Memory".

The tree of data connectivity

The goal of data connectivity is to allow people to communicate with everyone else. The form of the connection may be voice, text, video, files, or some other type of data. However, the ideal is that it can transfer between any two (or more) people.

So, how does that happen? Well, the actual form of the data is in files that have some type of format. These formats, or organized forms, are standardized so that it can be created and transmitted, and then received and used. Examples of these are Adobe PDF files, Audio MP3 files, and Video MPEG-4 files. Voice is usually digitally encoded using one of the International Telecommunication Union (ITU) standardized formats such as G.711 or G.729.

Once a file has been created, it is transferred to the desired recipient. The current dominant types of transferring may be classified into wireless and landline. Wireless includes cellular data (and voice), Bluetooth, and Wi-Fi. Landline (using a physical medium for transfer such as a cable or fiberoptic line) makes use of many different protocols.

Wireless is the current popular option for the "end user" -- the person who is making use of the device that allows them to transfer data (remember that voice is just one form of data). However, wireless has significant restrictions. These restrictions are distance and/or speed. Companies are now marketing devices called "femtocells" (the actual brand and name of the device may not include this name) which are placed in homes or businesses to allow faster transmission by reducing the distance between the cell phone or Wi-Fi device and a landline.

Yes, a landline. Because of transmission requirements (which go beyond the scope of this current blog), it is just impossible to handle all of the data needs without going to a landline. A landline is self-contained for bandwidth (data capacity) while wireless must compete with all other wireless activity. So, landlines will (in my limited ability to read a crystal ball) always be needed and they form the trunks and branches of the tree of data connectivity with the wireless devices now being used as the leaves.

Hackers are positive people

I was looking around at the movies coming up and looked into "The Social Network" which led me to Wikipedia for Mark Zuckerberg.

Once upon a time, I wrote a book about how computers work -- meant for the everyday person and trying to explain/show how the various parts of computers worked together. Although unpublished (and probably unnecessary anymore), one of the chapters dealt with hackers. According to Wikipedia, Zuckerberg said that hackers are people who aren't afraid to break something in order to make it better.

Personally, I would go a bit further. I would say that hackers are people who are curious about how software works, aren't afraid to break it, and who want to make it better (in the past, this often meant more efficient and faster, nowadays it more often means more features). At any rate, it is a positive purpose -- Bill Gates Jr., Wozniak (also a hardware tinkerer), and others are all hackers. I am also a hacker and proud of it.

So, why does the word "hacker" have such a negative connotation? Leave it to the sound bite. It sounds good and the media, rather than going into more detail as to what was actually done (which might bore a majority of their viewers/readers) just lumped all people working on software as hackers. This includes a sub-group of hackers which does NOT have such benevolent motives -- the "crackers". Crackers work to exploit the inherent weaknesses of software structure to allow misuse.

Crackers are a pain in the rear -- they do things for their own egos and pocketbooks and make the rest of us have to deal with their behavior. Hackers have made the fusionfalls (a current favorite of my kids), the facebooks, the Linuxes, and the spreadsheets possible (among thousands of other software programs). Hackers have found a home in the open source community but, for the most part, remain in individual obscurity.

Where did they go?

Well, I decided to be inspired by one of the Blogs I follow -- "The Retirement Bubble" and accept the fact that I just am not going to be a daily blogger. So, I headed to my blog and "ZAP", my last blog was no longer there. In fact, my stat counter for visits (which I watch not go up very fast ) went backwards from 184 to 121.

I'm sure that things of this nature happen to you, also. What can the reason be?

Well, first, of course, there is the jello-like consistency of memory. I could have just imagined that I posted a blog entry last month. People look at memory as the chronicle of the past but it just doesn't really work that way. If you think about doing something enough times, with enough detail, it will blur the boundary between "memory" and "dream". Given an amount of elapsed time, that boundary may easily disappear. I know people who have very fixed "world views" and you can tell them "yes" to a question and, because they just "knew" you were going to say "no", they will HEAR "no" and remember "no". This is a bit more severe of a split between "memory" and "dream". The bottom line is -- one cannot really rely on memory

But, do I think that is what happened? No. Of course it could be vanity -- "other people may not remember correctly but I certainly do". No, the main reason I don't think that was the case is because of the stat number. Everyone has certain areas where their memory is well exercised and more reliable. My stepdaughter can remember what someone wore for a given date within the past few months and practically forever about what SHE was wearing. Other things aren't so important to her and she just doesn't remember. For me, it is numbers. I can visualize that "184" in the stats area and I'm pretty sure it isn't a false memory.

There are some aspects to irregular posting that are certainly suspect. For example, some of the formatting aspects of this blog seem to be strange to me -- but, for that, I will just blame my memory and not doing this blog often enough.

Assuming that I'm not crazy and my memory is not totally faulty, where did the blog go? Two possible avenues seem to rise to the surface. One, a system crashed and the disk got backed up (which, for Google, does seem a bit scary to think that backups are unreliable). Two, I didn't do something correctly to commit the blog into permanent status.

Actually, there is a third possibility but paranoia just isn't my thing. "Someone" could have removed it. Since the blog was concerned with firmware and quality control (and Toyota) I guess that there is a little weight to that but I don't really believe it.

At any rate, my last blog vanished and I'll have to think about it a bit to start over the chain. The last blog was on embedded software (firmware) and quality control. The next was going to be about embedded software on cars, unit testing and system testing -- and the difficulties of fully system testing real-time software for interconnecting modules (groups of software). And the next was going to be quality control and testing in general.

However, since the first of the series has vanished I guess I'll think it all out again.

Google, if you're listening -- maybe YOU can find out what happened to my last blog .

Ready, Set, Stop

We've probably all seen a car in an intersection -- rear end over the crosswalk and front end partially blocking the outside cross traffic land -- and they just stay there, never getting a green light to go. Or perhaps they have stopped 30 feet behind the crosswalk and they're stuck (and you're stuck behind them). There really is no mystery -- they are beyond the range of the sensor in the road and the traffic light system doesn't know they exist.

Traffic light systems are ideal for computer programming assignments. The basic system is very simple but it can be increased in complexity to understand more and more possibilities of design. I have used such systems as examples in a couple of my books.

The simplest form of traffic light is a blinking four-way stop (red lights). Not much of an advantage over a four-way set of stop signs except more visible in the dark. The next version can make use of a simple mechanical timer and set of switches (rather like many mechanical pool pump timers). The timer can revolve at a fixed rate and close contacts with the appropriate lights in the traffic system. It probably proceeds like

Green Red
-t- Red
Yellow Red
Red Red
Red Green
Red -t-
Red Yellow
Red Red
and back to the beginning. The "-t-" indicates some type of delay -- the length of time that the green light stays on for that direction. Note the two times that both directions are Red. This is very important for safety reasons.

This simple mechanical system has a timer and a set of connections to lights. The timer is an input and the connections are outputs. Mechanical systems can be designed to allow for a beautifully complex set of conditions but the actual construction becomes more and more precise and difficult to mass manufacture. It is much cheaper, and easier, to start adding microprocessors and programs to handle more complex operations.

With programming, the inputs are often extended to a clock, a set of timers, and one or more sensors. These are all concerned with events that affect the output -- which may be extended to include walk lights in addition to traffic lights. The programming may start taking into account the day of the week, time of day, whether it is a holiday, how many cars are waiting in a lane, and many other options. Once again, it can get pretty complex -- but most of the complexity is hidden in the programming and, thus, mass manufacturing is still possible (even reduces the cost per unit when more are made).

So, the car is stuck because the sensor no longer can tell it's there and it cannot use that as an event to trigger a light change.

Why go into all this detail? Who cares? Well, I find it interesting in itself but it's also a good prelude to talking about embedded processors in cars and the relation between complexity, sufficient testing, and safety which is definitely in the news of late. See the next blog .

Basics of how email works

I have noticed that some of my friends are not really aware of just how email works. This isn't really necessary -- as long as it works the way one "expects". It only becomes a problem when it does NOT work the way that it is expected.

Email starts out the same way as paper mail. It has an address and it has a letter (or body). It may even include some type of contents (attachment). The actual format of an email body is only important for a corporate systems administrator -- you'll probably never have to worry about it. The way attachments are carried may be of interest but, once again, it will work for you or it won't work for you. One popular method is MIME (Multipurpose Internet Mail Extensions) which allows mixing various types of files (photos, movies, music, text, etc.) within the same email file.

An address consists of a user id an "at" sign and a mail server name. A server is a computer which provides services to other computers (possibly in addition to providing services to someone directly using the computer). These services can be acting as remote data servers or it can be as a mail server. A mail server acts as a post office with each individual user id acting to identify an individual post office box. Popular mail servers include gmail.com, att.net, verizon.net, charter.net, yahoo.com, and aol.com. These people-readable, "friendly", names are actually translated into machine-friendly numbers (such as 103.56.113.114) by a system of other servers which provide domain name services (DNS). These machine addresses are used by the Internet Protocol (IP) network to route messages to the correct servers.

Most mail servers act as a "post office" for many different user ids. However, it is always possible for you to have a computer in your own home that acts directly as a mail server for your own domain name. When you send mail to someone, it is routed to the mail server for that address. The computer that acts as the mail server may be located anywhere -- Ohio, Paris, London, Florida, Washington state, or wherever. The mail will stay on that server until someone "picks it up" and then deletes it (or the mailbox capacity is exceeded). The important point is that, for most people, the email actually exists on some other computer that may be far away.

In order to pick up your email, you have two basic options. You can use a browser (or other program) to connect directly to your mail server and read/delete/send mail. Or you can use a mail program (such as Outlook, Thunderbird, Mac Mail, or AOL) to connect to the mail server and download the mail on the server to the computer upon which you are typing. At the point of downloading, there are still two copies of the email -- one on the mail server and one on your local computer. However, this is a waste of storage space, so most mail programs give you various options (under "options" or "preferences" usually) to delete the copy of the email on the mail server. This can be done immediately, in three days, in a week, or an arbitrary interval.

And now you have your email and can deliberate on a thoughtful response.

http://technoglot.blogspot.com

What makes high tech "high"?

People, and the media, talk a lot about "high tech"? But what is high tech? Warren Buffett says that he does not invest in high tech -- not because he thinks that it is bad but because he feels that it is wisest to invest in companies that one understands. This allows a good understanding of the business and the market and the managerial capability to run the company.

High tech exists because of all of the levels of technology upon which it relies. Thus, it is at the apex (or top) of a very large pyramid. This is reflected by our education and what we are expected to be able to do at different periods of our education.

At the bottom of the pyramid are "simple machines" and, as listed in Susan Kristoff's "Introduction to Simple Machines", scientists in the Renaissance period listed six devices for simple machines. These are the lever, the wheel and axle, the pulley, the inclined plane, the wedge, and the screw. In order to create, or make use of, simple machines, a variety of "simple tools" are required -- such as hammers, screwdrivers, wrenches, pliers, saws, and shovels. To this list, I would add cutting instruments such as knives and chisels.

Of course, when you read through lists such as this, you will find yourself saying -- but what about scissors, and bolts, and nuts, and ...? Just because the Renaissance scientists made a specific list of six items doesn't mean that everyone will feel that is THE correct list. For example, I could argue that the wedge and the inclined plane are variations on the same thing. I would actually be tempted to classify into categories of mechanical movement such as lifting, pushing, pulling, and rotating.

It really doesn't matter. The fact is that there are some basic machines and tools that exist at the bottom of the pyramid. By using such basic devices, we can produce "low tech" -- a swing set, a door, a teeter-totter (for those that remember such ), pogo sticks, and so forth. These can all be easily built using basic devices and tools. Of course, the degree of "finish" for something will depend on the quality of the tools and the experience of the craftsperson. I can create hinges and a door but you probably wouldn't want it on the front of your house.

We now reach into the "middle technology" category. Note that things are not REALLY so nicely divided as something may easily be broken into parts that are of various levels of needs. When we get to middle technology, we get to phonographs (for those who remember such), steam engines, paddlewheels, flour mills, ships, and so forth. These are items where you might appreciate the work which goes into them but aren't likely to cause you to gasp with astonishment. And many moderately experienced modern young adults can probably make such. They take knowledge, tools, and the ability to design and follow directions. I could probably make a horrible sounding, but functional, record player (and record). Neither Bose nor Boston Acoustics will lose sleep over that.

Now, we come to high tech. High tech requires the use of middle tech tools and machines to create their products. A CD player requires the ability to create lasers, and smoothly precise rotating movements, and a lot of semiconductor chips, and wiring and special metals and materials. I could NOT create a CD player without first creating a lot of things that I would need prior to being able to create the CD player. High tech requires middle tech which requires low tech. And that is the real story -- high tech builds upon other techs.

http://technoglot.blogspot.com

Computer Literacy 101 -- what is a peripheral?

A computer system cannot often stand alone -- it needs a way to input data, it needs a way to output data and it needs a way to expand its capabilities. These devices are called peripherals. A keyboard is a peripheral. A monitor is a peripheral. The time panel on a microwave oven can properly be called a peripheral, although it may be part of the overall design and not optional.

Peripherals can be grouped in classes. One class is Input/Output (or I/O). These peripherals allow you to put in (input) data or to access (output) data. Another class would include removable storage systems -- a flash card, a hard disk, a CD-ROM unit. Other classes exist.

Input devices have a particular requirement from the operating system. Since it is unknown just WHEN data will be input, there must be a way for the operating system to notice that data are available. The two main ways of doing this are via polling and via interrupts. A poll is a periodic check for data -- like a child in a car asking "Are we there yet?". An interrupt is like a tap on the shoulder. Different systems will use different methods. A poll does not take long but there will be many times that the answer will be "no" -- and, thus, the time taken is "wasted". An interrupt takes much more time because it is necessary to save the current situation (maybe you're in the middle of a program) before the interrupt can be handled. Let's say that handling an interrupt takes 50 milliseconds and a poll takes 1 millisecond. If an event occurs once a minute, then doing an interrupt will take less time than polling once a second (50 < (60 x 1)). However, if the event occurs twice a minute, then polling is more efficient (50 > (30 x 1)).

A keyboard is an input peripheral. So is a mouse. In the case of a keyboard, a specific data value is sent when a key, or combination of keys, is pressed. This is usually kept in a temporary memory buffer that can be read by another program that is currently accepting input from keyboards (maybe a word processing program, maybe a browser window). A mouse sends two types of information -- a change in location and key presses. The key presses are handled similar to those of a keyboard. However, the change in location is done by the computer keeping track of the "location" of the mouse. When the computer starts up, the mouse is considered to be in a "default" (starting) location (often the upper left of your monitor). If you move your mouse to the right, it keeps track of how far to the right it has moved. Note that it isn't usually a one-to-one movement or your mouse pad would have to be as large as your monitor. Also, if you pick up the mouse and move it, it is as if it never moved.

Printers and monitors are typical output peripherals. Printers are fairly straightforward (although the actual data may not be such) -- your output may say "give me a new page", "print the letter 'a'", "go to the next line", and so forth but it basically is given a set of commands in sequence. A monitor, currently, is more complicated because of the idea of active windows and locations. So, in a modern operating system, the computer not only needs to keep track of where the mouse (as reflected by the cursor displayed on the monitor) but what program is making use of input while the cursor is at that location and what menu or button must be activated if there is further input (keyboard or mouse click) while at a specific location within that program's active space (or window). The input devices are actually what are causing changes about what you see -- the monitor just reflects the effects of that input.

And that pretty well covers Computer Literacy 101 -- though I would be happy to try to address any areas (of the many) that I have neglected.

Computer Literacy 101 -- what is an operating system?

An operating system (or OS) is a special program that allows other programs to run. This is the core of a general purpose computer -- the ability to run programs that are not pre-determined. A specialized computer (or microprocessor) may be able to run multiple programs but they are known in advance and, thus, the system can be designed to just run those programs (simpler, faster, and smaller).

As a more general definition, an operating system manages the resources of a computer. Sometimes, it is defined by a hierarchical model (sometimes known as the "onion" model) because there are services that are provided by the primary section of the operating system. Then there is another layer that provides new services plus makes use of the primary section. Then another layer that makes use of the other two layers, and so forth.

Some of the services provided by an operating system (in "layer order") are task (program) management, memory management, process (tasks communicating with one another) management, device management (such as hard disks, or CD-ROM drives, and so forth), and finally file management.

Because the applications make use of operating system services, which in turn rely on other "lower layer" services, most applications are not portable between different operating systems. This is why a program that works with Windows (a particular operating system) may not work on a Macintosh (running Mac OS X, a different specific operating system) or under a system running UNIX or Linux (two closely related operating systems).

There is an apparent exception to this -- but it really still follows the same rules. If one uses a browser that executes a program within the browser, that program may work with browsers running on computers using different OSs. It appears to be OS independent (able to work under any operating system) but, actually, it is making use of a set of services that have been defined to have the same use on multiple operating systems. Because this set of services, or interface, between the program and the next layer is the same, the program can run under different operating systems -- but the underlying program that provides that interface is still operating system dependent.

There is little agreement on what Operating System is "best". In general, the one that provides the services that you need, and the applications you need, for the lowest price and greatest speed is "best" for you. (It may not be the best for someone else with different needs.)