Power supply/ charging

Deutschen Post electric vans in 1953-09-29 in Berlin. Electric vehicle batteries can be used to provide emergency electric power during power outages, to ensure that all necessary computer controlled functions in a house continue to operate.

Computer devices are dependent on electricity to operate. Increasingly, devices use battery storage/ power, to gain a temporary independence from the electrical power network. Various forms of small scale, local energy production (solar, wind) can even lead to a more permanent independence. However, not everyone is in a position to become permanently independent from the grid.

An electrical power blackout/ cut/ failure/ outage is the loss of electrical power somewhere in the network affecting the supply to an end user. These may be caused by faults/ damage at power stations, substations, transmission lines, short circuits, circuit breaker operation. A transient fault is a temporary loss of power, that is automatically restored once the fault is cleared. A brownout is a drop in voltage in an electrical power supply. Brownouts can cause operational problems. A blackout is the total loss of power to an area. They may last from minutes to weeks depending on circumstances. Rolling blackouts are planned blackouts that occur when demand exceeds supply. It rotates customers, so that at any given time some receive power at the required voltage, while others receive no power at all. Preventative blackouts are also used as a public safety measure, for example, to prevent wildfires around poorly maintained transmission lines.

Batteries in electric vehicles as well as solar panels are ensuring that there is always a minimal amount of electric power available, even if there is a grid related blackout. Circuits have to be designed so that electricity is not fed into the grid at these times, because that power could represent a hazard to people working on the lines to restore power.

Desktop and Tower computers

There are many different form factors used to make desktop and tower computers. These motherboard specifications determine dimensions, power supply type, location of mounting holes and ports. This ensures that parts are interchangeable over time. Two are especially important. The ATX specification was created by Intel in 1995, and is still the most popular form factor. Here the power supply offers several different voltages to meet the specific needs. These include +3.3 V, -3.3 V, +5 V, -5 V, +12 V and -12 V. There were and are attempts to offer just 12 V, but this reduces the selection of components available.

This type of computer has a power supply built into the computer case. It is suitable for power intensive assignments such as gaming or video rendering. Some can provide 500 W of power. The tower format is especially attractive if a large number of expansion cards are needed. One challenge with these is the need for active cooling. Fans can be noisy. The open nature of the case means that it will attract and accumulate dust, which will have to be cleaned at regular intervals.

The Mini-ATX family of motherboard specifications was designed by AOpen in 2005 with Mobile on Desktop Technology (MoDT). This adapts mobile CPUs for lower power consumption. With a simple but effective thermal design, it is suited for passive cooling, making it virtually silent. Manufacturing costs and overall operating power requirements are lower relative to active cooling designs. A DC-to-DC converter removes the power supply from the case, reducing system size. This type of computer is suitable for general use. The number of expansion cards is limited.


Almost all modern laptops use Lithium Ion (LiIon) batteries and use 19 V chargers. Each battery arranges LiIon cells in series. A LiIon cell has a maximum charging voltage of 4.2 V, although slightly more voltage is applied in practice. Voltage needs: One cell = 4.2 V; two cells = 8.4 V; three cells = 12.6 V; four cells = 16.8 V; five cells = 21 V. A charger uses switched mode power supply (SMPS) to convert the supply voltage to required voltage, sometimes using a boost converter (steps voltage up), but usually a buck converter (steps voltage down). A 19 V buck converter could charge up to 4 cells in series. When a LiIon cell is close to fully discharged it’s terminal voltage is about 3 V. A buck converter can accommodate this reduced voltage to maintain its charging efficiency, which can exceed 95 %.

Handheld Devices

There are three charger plugs in common use on handheld devices: micro-USB-B, USB-C and Apple Lightning. A cable will typically have a connector for one of these standards on one end, and a standard USB-A 2.0 connector on the other, that can be plugged into a charger, which – in turn – is plugged into a wall socket.

The micro-USB and lightning connectors will likely disappear in Europe, as the European Union has mandated use of a common charging connector, which will probably end up being USB-C.


As stated in an earlier post, USB originally allowed power to flow downstream from a Type-A connected device to a Type-B connected device. This situation has changed with the introduction of USB-C connectors, which combine A and B characteristics. It is not easy to see where power is flowing.

Type of DeliveryCurrentVoltagePower
Low Power USB 3.0150 mA5 V0.75 W
High Power USB 3.0900 mA5 V4.5 W
Battery Charging 1.25 A5 V25 W
Standard USB-C3 A5 V15 W
Power Delivery 1.0 Micro-USB3 A20 V60 W
Power Delivery 2.0/3.0 USB-C5 A20 V100 W

One of the most common devices needing power to operate are external drives. For example, Western Digital My Passport external hard drives that feature 2.5 inch drives, are powered by the computer, using a USB Type-A connector for data and power. In contrast, Western Digital My Book external hard drives feature 3.5 inch drives, that also come with a USB Type-A connector for data, but with an AC adapter with wall socket plug for power.

USB Battery Charging defines a charging port, which may be a charging downstream port (CDP), with data, or a dedicated charging port (DCP) without data. Dedicated charging ports on USB power adapters can run attached devices and battery packs. Charging ports on a host are labelled such.

In the computer world, one is perpetually in a transition period. There is always something newer and potentially better, and something older but tested and, hopefully, more reliable. Thus, a Western Digital G-Drive comes with three cables: USB-C to USB-C, USB-C to USB-A and a power cable that attaches to an AC power adapter. For computers that can provide power over a USB-C connector, only the first cable is needed. For computers without USB-C power, this first cable connects the AC adapter to the G-Drive, with the second cable connects the G-Drive to the computer.

Power over Ethernet (PoE)

With domotics (smart houses) becoming increasingly popular, it is becoming increasingly advantageous to install and use Ethernet cables to ensure devices are able to communicate effectively. While some switches only provide data transfer, many switches offer power, using one of the many Power over Ethernet standards.

There are two different approaches to providing power. Power sourcing equipment (PSE) that provide power on the Ethernet cable, typically a network switch, is called an endspan or endpoint. The alternative is an intermediary device, a PoE injector, also referred to as a midspan device.

A powered device (PD) is any device powered by PoE. One common device is a room controller which has sensors collecting data about a room, and actuators such as a solenoid capable of opening and closing a heating vent. In the future many computing devices should be able to receive power directly from an Ethernet cable.

PoE is expected to become a DC power cabling standard, replacing individual AC adapters in a building. While some are concerned that PoE is less efficient than AC power, others argue that it is a better solution because a central PoE supply replaces several/ many AC circuits with inefficient transformers and inverters, compensating for any power loss from cabling.

Standard 802.3af Type 1at Type 2bt Type 3bt Type 4
Power at PSE15.4 W 30 W 60 W 100 W
Power at PD 12.95 W 25.530.0 W 51 W 71 W
Voltage at PSE44.0–57.0 V50.0–57.0 V[50.0–57.0 V 52.0–57.0 V
Voltage at PD 37.0–57.0 V42.5–57.0 V42.5–57.0 V41.1–57.0 V

Inductive Charging

Inductive charging involves wireless power transfer, using electromagnetic induction to provide electricity to portable devices. The most common application is the Qi wireless charging standard. Devices are placed near an inductive pad. There is no need for electrical contact with a plug, or for devices to be precisely aligned, for energy transfer. Advantages of wireless charging include: corrosion protection and reduced risk of electrical faults such as short circuits due to insulation failure; increased durability, because there is significantly less wear on the device plug and the attaching cable; No cables; Automatic operation.

There are some disadvantages: Slower charging, devices can take 15 percent longer to charge; more expensive because of drive electronics and coils in both device and charger; there is a certain inconvenience cause by an inability to move a device away from its pad, while it is being charged; there is an assortment of incompatible standards that not all devices support; devices get hot when charging, and this continued exposure to heat can result in battery damage.

The Qi standard is supported on devices fro Apple, Asus, BlackBerry, Google, HTC, Huawei, LG Electronics, Motorola Mobility, Nokia, Samsung, Sony and Xiaomi. Released in 2008, the Qi standard had by 2019 been incorporated into more than 160 handheld devices.

Uninterruptible Power Supply

An uninterruptible power supply (UPS) provide electricity to an attached device if the main supply becomes unavailable. The duration of this protection varies. This is particularly important for desktop and server devices that do not have built-in batteries, in contrast to those with batteries, found in handheld devices and laptops. Even if a UPS is designed for mission critical equipment, it can be nice to have in a residence. Perhaps the most important device to connect is to a UPS is the router, to allow communication outside the residence. The local internet service provider (ISP) should have the rest of the network protected with their own UPS. What they actually provide varies.

Data or voice communication with a handheld device on cellular network can be the most effective way of communicating in an emergency situation, during a blackout. This is because the cellular base stations should have their own backup power sources, allowing them to operate normally.

Surge Protection

All electronic devices should be protected against surges = situations where voltages increase above specified levels, even if just for one or more seconds. Surge protectors can prevent this form of damage. This is probably best provided by having surge protection built into the circuit-breaker box.

Video Connectors

Some technical journalists are more dramatic than others. One described a display/ monitor/ screen as a window opening onto the soul of a computer, and the purchase of an appropriate one, a make or break experience. Both statements are exaggerations. Within a given budget, one must attempt to optimize the value of each component, and find a compromise.

There are several terms that will have to be understood to appreciate video connectors. Source, here, will be used generally to describe a machine producing a video signal, possibly through the internet, or stored as a file, or produced by a program. A display is a video screen capable of showing video images. A source is usually connected to a display using a cable. The ends of the cable, as well as the physical ports on the machines are connectors.

Most of the time graphic content on a display is something relatively static, including a desktop image, a text being written, or a list of files. At other times, the content may be more dynamic, such as a video film or a game.

A video connector is often overlooked because it is smaller than a display. Yet, it determines which displays can be used. This applies to laptop as well as desktop machines, home media centres, and handheld devices. There are a lot of standards associated with computer displays. Wikipedia lists 69 display standards, 22 signal and 32 connector standards. Fortunately, most of them can be forgotten as relics of the past.

One of the challenges with writing about video connectors is that there are several groups of intensive video users, who have specific demands. Some of these people are video editors, others are film fanatics, but most are gamers. They probably know very precisely what they want, and have other sources for advice. Intensive users will probably want to use a DisplayPort, version 2.0 on both source and display, connected using an ultra-high bit rate 10 (UHBR 10) cable. Mac users with USB-C connectors will want to connect to USB-C displays. With these extremists out of the way, the rest of this weblog will consider the needs of more ordinary users.

Some comments about specific video connectors

In computing’s Middle Ages, a Video Graphics Array (VGA) connector emerged in 1987. It was used on video cards, computer displays, laptop computers, projectors and even high definition television sets. Later, a smaller mini-VGA port was sometimes provided on laptop computers. This connector is still found on large numbers of sources and displays.

The Digital Video Interface (DVI) was designed to replace VGA in 1999-04. It can transmit uncompressed digital video in three modes: DVI-A (analog only), DVI-D (digital only) or DVI-I (digital and analog). It is backward compatible for use with VGA displays.

High-Definition Mulitimedia Interface (HDMI) dates from 2002-12. It is backward compatible with DVI-D and DVI-I, but not DVI-A. There are five types of connectors in use Type A = standard-HDMI; Type B = dual-link-HDMI (never used); Type C = mini-HDMI; Type D = micro-HDMI; and Type E = Automotive Connection System (ACS).

DisplayPort dates from 2006-05. It is backward compatible directly or indirectly, with all of the previously mentioned connectors. All DisplayPort cables are compatible with all DisplayPort devices, but may have different bandwidth certification levels (RBR, HBR, HBR2, HBR3). The major difference between DisplayPort and HDMI, is that while HDMI originated with consumer electronics, DisplayPort was oriented towards computer standards, especially at the more expensive end of the market. While there are several other DisplayPort connectors, only the Full-size DisplayPort and Mini-DisplayPort connectors will be discussed further.

What types of connectors are being used on each machine? Machines can be divided into sources and displays. Sources include different types of handheld devices (aka mobile/ cell phones, tablets), laptops, desktops and media players. Displays include monitors, televisions and projectors.

If any sources or displays support only VGA or DVI connections, these units should be considered for replacement. Modern TVs and displays have HDMI ports, DisplayPorts and/ or USB-C ports. Laptops typically have HDMI, micro-HDMI, standard DisplayPort or Micro-DisplayPort or, increasingly, USB-C ports.

The easiest connections are between machines that use the same family of connectors. It doesn’t matter what type of DisplayPort plug one is using, as long as the connector ends match those on the devices. One should buy cables with the certification level of the most advanced device (source or display).

A similar situation occurs with HDMI. The ends have to match, and the cable quality should mirror that of the best machine.

If any source equipment features DisplayPort Dual-Mode (DP++) this is a standard which allows DisplayPort sources to use simple passive adapters to connect to HDMI or DVI displays. Again, it is a relatively simple solution.

If both source and display have HDMI ports, an HDMI cable can be used. If different technologies are used an adapter, such as HDMI-to-DisplayPort, or vice versa, can be used. Similarly, there are cables with VGA, DVI, Micro-DisplayPort, DisplayPort or USB-C connectors at one end and HDMI at the other end.

A USB-C to HDMI / USB-C/ USB 3.0 multiport adapter is practical for computers using USB-C for AV output to displays, televisions and projectors, with video resolutions up to 4K (3840X2160P/30HZ). Source devices include MacBooks, Chromebooks, as well as several Windows and Linux devices.

Using this approach with laptops gives all of the disadvantages of a desktop without any of its the advantages. The laptop may not have enough ports for everything. It can be time-consuming and frustrating unplugging then reattaching peripherals after every move.

Previously, docking stations solved these problems. Peripherals, such as keyboard, mouse, display were plugged into the docking station, along with the laptop. Unfortunately, these were often brand and sometimes even model dependent. General-purpose docking towers are now available.

Handheld Devices

A Mobile High-Definition Link (MHL) adapter and a standard-HDMI to standard-HDMI cable is used to connect Android devices to HDMI displays. Here are the steps to follow.

  1. Use a MHL (micro-USB to standard-HDMI) adapter.
  2. Plug the male micro-USB (small) end of the adapter into the Android device.
  3. Plug one end of a HDMI cable into the MHL adapter.
  4. Plug the other end of a HDMI cable into a TV.
  5. Turn on the TV.
  6. Change your TV’s input to the relevant HDMI port.
  7. Wait for the Android screen to display on the TV.
  8. To work the depicted adapter needs a 5V 1A external power supply (5V 1A) to.power the adapter and to charge the Android device. Plug the charger’s male micro-USB end into the female micro-USB port on the adapter.
  9. Note: When using such an adapter for the first time, the phone must be rebooted after the adapter is connected to the phone, otherwise there will be no HDMI output.

Similar procedures need to be followed to connect an iPhone Lightning connector to a HDMI connector on a television using a adapter. Once again, but depending on the adapter, it may be necessary to have the charger plugged into the adapter for it to work. Others only need to be plugged in if the iPhone needs to be charged.


As stated in the previous weblog post, the future of video connectivity is the USB4 protocol and the USB-C connector. While every USB-C port looks the same, they do not all provide the same functions. This is especially true for both power and video. Its main advantages include high data/ video throughput, and ability to transfer electrical power. This means that USB-C monitors will get power as well as data from the source device they are connected to.


Welcome to Brock’s 300th weblog post.

Why do I subject myself, and readers, to this massive outpouring of words, that a weblog represents? There are two reasons. The first is my addiction to writing, combined with an inability to keep a diary. When I try to write a diary, which used to happen about once a decade, it is more a reflection on the day’s events, than a chronicle of them. My determination as a diarist lasts about a week. There are a thousand excuses for any failure to write, not finding the diary being paramount.

The second reason involves brain stimulation. Novelty releases dopamine in the brain. which, in turn, stimulates the amygdala, the site of emotion, and creates a pleasurable feeling that is associated with the new activity. Fun encourages more fun, which is what writing a weblog post should be about.

A weblog suits my personality: my mind prefers to focus on topics, rather than on events, or on people; a keyboard is faster than a pen. Yet, despite its slowness, I still use pen and paper to write other texts, for handwriting is an skill that should be retained and sometimes promoted. My one vanity is a pride in my handwriting, which – when I take the time – is small and legible and produced using liquid blue ink. I have tried black, red and even green, but prefer blue.

Changes are easier to make with word processors, than they are with pen on paper. While it may not be any easier to start writing a blog than to begin an entry in a diary, but it is easier to continue again at a later date, and to make corrections. Innumerable drafts can be kept, that can be published in any order, or even discarded. Not even my hairdresser knows how many drafts I have stored away, awaiting further inspiration. As I write this sentence, there are 330 posts in total, 293 published, 6 scheduled, 31 in draft form, and one in the bin. That is the number on my private website, not on the Keywords website or inside my computers or on external drives.

As I write these lines my mind returns to the early 1980s, and to the technology available at the time. A computer terminal can show what was right, and what was wrong with an era that introduced the masses to computing.

The Digital Equipment Corporation (DEC) VT 100 terminal was a companion for three years. Designed for computer programming, rather than word processing, with 80 columns and 24 lines of white text against a black background. The monitor/ screen was fixed in position, too low and unsuitably angled. The keyboard was far too high, and certainly not ergonomic. The user was expected to adapt to the machine.

Digital Equipment Corporation VT-100 terminal. (Photo: Jason Scott)

The Norsk Data (ND) system, with its ND-Notis word processor was a vast improvement. The Tandberg TDV-2200 terminal was the most ergonomic terminal in the world at the time, its brown and beige monitor/ screen featured green text on a black background, and was fully adjustable in every direction. Its beige, brown and orange keyboard, was a delight to use. I used such a system, in two different environments, for four years. Even the colour scheme was explained in ergonomic terms, with claims that the colours chosen were more restive than any other colour combinations available. The machine was expected to adapt to the user.

A Tandberg TDV-2200 terminal. (Photo: Tore Sinding Bekkedal) Uploaded to Wikipedia in 2006 by by User:Arsenikk aka Alasdair McLellan. Thanks, Alasdair.

It is easy for old men to focus on the past, but that is not what I want to do here. I want to encourage people of multiple ages and genders and ethnicities and interests to reflect on their lives, and on society, and then to express themselves. How will people in a future age know what it was like to live at this time, if you don’t tell them? How will people in distant lands, know what you experienced, are experiencing? Help them to understand, and you might also begin to understand yourself, and your place in the world.

A weblog does not have to be written words. It can be words or music as sound waves, or assorted movements as video. At the moment, it is more problematic to diffuse smells and tastes, but a time may come when this is possible. Poetry, drama, comedy, performance are all valid forms of expression. It could be images: photographs as works of art or mirrors of contemporary life; drawings, paintings, collage; sculpture that is knitted, cast in bronze or chiselled away from stone; culinary masterpieces. Craftsmanship is of particular importance to me, and I admire all forms of it: woodworking, metalworking, moulding in plastic, papier-mâché, sewing.

As is my habit, I encourage people to write weblogs, rather than to use social media. Restrict it to your best friends and closest family, and perhaps a couple of people you don’t know that well, to keep it honest. Write about the topics that interest you. Perhaps you know something about tractors, or dogs or playing congas.

With 7.7 billion people, the world is being consumed, so there is less nature for other species to inhabit, and ourselves to enjoy. We – in the west – will have to learn to consume less, so that others may fulfil their lives. Hopefully, this will also mean that we will work less, and spend our free time in pursuits that benefit others as well as ourselves. Even billionaires would benefit, if there was increased equality. Perhaps you could find, then document, ways of doing things better, that use less energy or water or materials. Perhaps you could invent, then document, new ways of having fun: A new game, dance, sport or toy.

Have fun everyone, and thanks for reading!

Randy Suess (1945 – 2019)

Randy Suess in 2004 as he appeared in BBS: The Documentary. Photo: Jason Scott

This weblog post is published on the 42nd anniversary (2020-02-16) of the opening of the CBBS (1978-02-16), the world’s first bulletin board service. It also commemorates the life of Randy John Suess (1945-01-27 – 2019-12-10). Born in Skokie, Illinois, Suess served for two years in the U.S. Navy, before attending the University of Illinois at Chicago Circle. He worked for IBM and Zenith.

In the 1970s, Suess was an amateur radio operator, with call sign WB9GPM. He was an active member of the Chicago FM Club, where he helped with maintenance on their extensive radio repeater systems.

However, Suess is most famously remembered as the co-founder and hardware developer of the first bulletin board system (BBS), along with partner and software developer Ward Christensen (1945 – ). They met as members of the Chicago Area Computer Hobbyists’ Exchange, or CACHE about 1975. Development of the BBS started during the Great Blizzard in Chicago, and was officially online (an expression not used at the time) as CBBS = Computerized Bulletin Board System, on 1978-02-16.

The early development of this and other bulletin board systems is documented in a previous weblog post, and more extensively in BBS: The Documentary an 8-episode documentary series created by computer historian Jason Scott, made from 2001-07 to 2004-12.

The CBBS consisted of a S-100 computer with an 8-bit, ca. 1 MHz processor, 64kB RAM and two single-sided 8″ diskettes each holding 173 kB formed the basis of the system, along with a Hayes MicroModem 100 running at 300 baud. The operating system was CP/M, but it ran other software was written in 8080 assembler, and automatically loaded whenever someone dialed in at: 312-545-8086.

Attention to detail was important for the survival of the system. The floppy disk drive motors ran from mains electricity, and quickly burned out if left on. So the system was modified by Suess to turn itself on when the phone rang, and to keep going for a few seconds after the caller had finished to let the computer save its data, and then quietly go back to sleep. A unique feature of CBBS, was that if callers typed inappropriate words, these would be recognized and the system would log the caller out. Entering too many unproductive keystrokes would have the same effect.

Suess hosted CBBS, because his house in the Wrigleyville section of Chicago could be called without paying long-distance charges by anyone in Chicago. By the time the system was retired in the 1980s, its single phone line had logged over 11 000 unique users, and received more than 500 000 calls. A version of CBBS has run periodically, more than forty years after its inception, demonstrating the state of technology at the end of the 1970s.

Because of his interest in Unix systems, in 1982 he created the world’s first public-access Unix system, then called “wlcrjs”. In 1984 this became Chinet (Chicago Network), which connected to the internet through a satellite radio. It ran on one of the earliest Compaq portable machines, with a 4 MHz 8088 processor, 640kB of memory, and a 10 MB hard drive.

In the early days of Chinet, the Internet was still a research tool, unavailable to the general public. E-mail and newsgroup accounts were obtained from a university computer or a BBS-like system. There were no ISPs (Internet Service Providers). E-mail and newsgroup postings were relayed from one computer to the next using UUCP (Unix-to-Unix Copy), a suite of computer programs/ protocols allowing remote execution of commands and transfer of files, email and netnews between computers, mostly at night, mostly over regular telephone lines at 1200 or 2400 Baud. The entire content on the internet was so small that it could be downloaded in a single evening. This meant that Chicago area users could browse a global collection of data without paying long-distance telephone rates.

In the late 80’s, Chinet had 12 dialup ports for between 300 and 600 active users. Later these were replaced with 22 phone lines that connected to a bank of modems, operating at considerably higher speeds. Eventually, the UUCP model became obsolete, with more companies getting direct Internet access, and ISPs offering inexpensive access to consumers. Chinet’s dial-up port usage started to decline.

Chinet then started using PicoSpan to replace its BBS software. Eventually, yapp (Yet Another Picospan Program) replaced PicoSpan and remained in use until Chinet migrated from Unix shell-based access to web based interfaces in the late 1990’s.

Despite a fire in 1996-05, Chinet still exits today, entirely web-based, running Simple Machines Forum software on a Debian GNU/Linux system.

Suess was married twice, first to Agnes Kluck and then to Dawn Hendricks, both marriages ended in divorce. He had two daughters, Karrie and Christine and one son, Ryan.

Randy Suess died 2019-12-10 in Chicago, Illinois. Currently, CBBS is operative, with information available about Randy Suess and his death.

Full disclosure: I am a registered user of CBBS/ Chinet, Chicago.

Universal Serial Bus

Older USB connectors are being replaced with USB-C (bottom right). Photo: Stéphane Mottin.

Conclusion: If you are considering investing in new computing devices carefully consider ones equipped with USB-C ports. This is the technology of the present and future. USB-A, USB-B, Mini-B and Micro-B connectors are relics of the past. However, devices with them should not be discarded. Cables with two different USB types on each end enable interconnectivity.

The Universal Serial Bus (USB) standard simplifies and improves the interface between a host computer and peripheral devices, with minimal operator action. Its interface is self-configuring. Connectors are standardized, so any peripheral can use any available receptacle. Usually there are no user-adjustable interface settings. The interface is “hot pluggable”, so peripherals can be used without rebooting the host. Small devices can be powered directly from the interface. Protocols for recovery from errors are defined, increasing reliability.

The USB standard specifies cables, connectors and protocols for connection, communication and supplying power to and between computers (Host or A-side) and peripheral devices (B-side). Peripherals include external disk drives, keyboards, mice and printers. However, they are not the only connectors. Screens typically use HDMI and other video connectors, the subject of a later weblog post. Similarly, Ethernet cables are preferred for connecting desktop computers and other devices to computer networks.

Today, most new Android handheld devices aka smart phones use USB-C (type C) connectors for charging and data transfer. Older Android phones have a Micro-B port. Apple iPhones (since iPhone 5) and most iPads use a Lightning connector. While the USB-C and Lightning look very similar, they are not interchangeable.

Fourth-generation MacBook Pro laptops, first released in October 2016, use USB-C for all data ports, and for charging. Windows laptops using USB-C ports for charging include some Acer Aspire, Asus Zenbook, Dell XPS, HP Sprectre and Lenovo ThinkPad models. Many other laptop models use an assortment of chargers, usually incompatible with everything else.

While the European Union has relied on consensus to standardize handheld device connections, this has not worked. While most manufacturers use USB-C connectors, Apple uses a Lightning connector. Now, the EU has said it will legislate compliance that will force all providers of handheld devices, including Apple, to use USB-C connectors. When implemented, this will probably have implications for the entire world.

USB connectors are at the heart of legacy-free computers, a term devised by Microsoft to describe a PC without a lot of the equipment previously found on beige boxes. Much of it large and slow. Most users appreciate this redesign, and especially the fact that a legacy-free PC must be able to boot (start up) from a USB device. The exception is that gamers, because of latency (time delay) issues, want to retain their PS/2 keyboard connectors.

Work on USB began in 1994, with a mandate from seven companies: Compaq, DEC, IBM, Intel, Microsoft, NEC, and Nortel. The goal was to replace a multitude of connectors with a single interface, and to increase data rates to and from external devices. A development team was established by Intel at Folsom, California led by Ajay Bhatt (1957 – ). The first integrated circuits supporting USB were produced by Intel in 1995.

The USB standard is currently maintained by the USB Implementers Forum (USB-IF), with four generations of specifications: USB 1.x (1996), USB 2.0 (2000), USB 3.x (2008, 2013, 2014, 2017) and USB4 (2019).

USB 1.0 ports are no longer relevant. However, efforts have been made to make all interfaces made after that backwards compatible. Thus, USB4 is backwards compatible with everything between USB 3.2 and USB 2.0.

ProtocolsUSB 2.0
USB 3.0
USB 3.1
USB 3.2
Data rate 480 Mbit/s5 Gbit/s10 Gbit/s20 Gbit/s40 Gbit/2
Type AOriginalBlueBlueNoNo
Type BOriginalBlueBlueNoNo
Type CYesYesYesYesYes

USB 1.0 from 1996-01 provided 12 Mbit/s of data transfer. When USB 2.0 was introduced, an unshielded cable version allowed for the attachment of inexpensive peripherals at a data rate of 1.5 Gbit/s.

USB Connectors

There are two versions of USB connectors one on a device and the other that fits into it on a cable. The device or female connector is referred to as a receptacle or port. The cable or male connector is referred to as a plug. Originally, a USB connection was always between a host or hub at the A connector end, and a device or hub’s upstream port at the B connector end. This is why peripherals, such as printers, use Type-B connectors. With handheld devices, the charger is regarded as the A end, while the device is regarded as the B end. Things are no longer so simple.

Port Type-A Type-B Mini Type-B Micro Type-B USB-C
Pins 4 to 9 4 to 9 4 to 9 4 to 9 24
Insertion/ removal cycles 1 500 1 500 5 000 10 000 10 000

The Future: USB4 & USB-C

The future of USB connectivity is the USB4 protocol and the USB-C connector. Yes, both of these could be replaced, and probably will be sometime in the future, but both represent reality now. While every USB-C port looks the same, they do not all provide the same functions. The main functions are data, video and power transfer. It is not possible to tell by looking at the port what is incorporated. If there is no documentation stating otherwise, consumers have to assume that they are simply data ports.

The USB-C connector began its use using the USB 3.1 protocol, which allows data transfers at 10 Gbps, theoretically twice as fast as USB 3.0. The USB 3.1 protocol can also be applied to USB 3.1 Type-A ports. Note: USB-IF has created unnecessary name confusion in that 3.0 connectors are also known as USB 3.1 Gen 1 & USB 3.2 Gen 1 x 1 while USB 3.1 connectors are also known as USB 3.1 Gen 2 & USB 3.2 Gen 2 x 1. The new USB 3.2 port was referred to as USB 3.2 Gen 2 x 2. The x 1 or x 2 refers to the number of lanes.

USB4 incorporates the Thunderbolt 3 protocol into the USB mainstream. The Thunderbolt interface was developed by Intel and Apple. It combines PCI Express and DisplayPort into two serial signals and provides DC power. Thunderbolt 1 and 2 use a Mini DisplayPort connector, whereas Thunderbolt 3 uses the USB-C connector.

USB Cables

Depending on phone, computer and vehicle configuration several different cable types may be required. In Scandinavia, Clas Ohlson stores offer a large selection, as do many specialist stores and online stores.

  • Android devices
    • USB-Micro B to USB-A: Connect older Android phones to older chargers, older computers, and older automobile data ports.
    • USB-C to USB-A: Connect newer Android phones & newer iPhones to older chargers, older computers and older automobile data ports.
    • USB-C to USB-C: Connect newer Android phones to USB-PD (power delivery) chargers, USB PD compatible batteries, some computers (with USB-C ports), 12V car chargers, newer automobile data ports.
  • Apple devices
    • Lightning to USB Type-A: Connect most iOS devices to legacy automobile data ports for CarPlay
    • Lightning to USB Type-C: Connect most iOS devices to current generation macOS devices using USB PD compatible batteries, wall chargers, and 12V car chargers.
  • Other
    • USB Type-A to proprietary cable/magnetic connector charger for Apple Watch or Samsung Galaxy Gear/Android Wear or older Apple Mac equipment.

Additional information on USB-C ports will be presented in the two next weblog posts in this series: 7. Video connectors (2020-02-18) and 8. Power supply/ charging (2020-02-25).

An Aside: PS/2 keyboards

First, a PS2 keyboard is not a PS/2 keyboard. The former refers to Sony’s Play Station 2, launched in 2000. The latter, to ports on IBMs third-generation personal computer, the Personal System/ 2, launched in 1987. It is an ancient and outdated system. Yet, gamers often prefer to use PS/ 2 keyboards (and sometimes even mice) for several reasons. First, PS/2 is analog. Whenever a button is pressed, it sends a command to the computer immediately. This contrast with USB, where the computer polls USB ports, and through them attached devices, at a rate dependent on the frequency of the port. Previously, this was about 125 Hz or so, which could introduce a latency (delay) from 0 to about 8 ms. Polling frequency on modern computers is about 1000 Hz, which reduces this latency to a maximum of 1 ms.

PS/2 keyboards also support N-Key rollover, which allows users to press as many keys as they want, simultaneously. This was not possible with USB keyboards, however many newer USB gaming keyboards support this now.

PS/2 peripherals work immediately without drivers. This is especially useful when diagnosing motherboard and related problems that USB devices cannot detect.

PS/2 devices are not hot-swappable. If a device is plugged into a PS/2 port when a computer is operating, the machine will have to be restarted for the device to function.

Unlike keyboards, USB mice have an adjustable polling rate, allowing them to have polling rates of up to 1000 Hz. Thus, they have had far fewer issues than USB keyboards.

PS/2 hardware is being phased out, and is unavailable on many modern gaming motherboards = a printed circuit board containing the main computer components along with various connectors. Unless that hardware is built into the motherboard, there is no point in using PS/2 equipment, and no point in using a USB adapter to correct any of USB’s deficiencies. At that point it is “game over” for PS/2, and the user might as well use USB peripherals.

Domotics: Laundry

Open air museum Roscheider Hof, Germany, The history of laundry (Photo: Helge Klaus Rieder)

Full disclosure. At one time, I had responsibility for laundry, washing the family clothes/ bed linen/ textiles more generally. Unfortunately, my supervisor was not totally satisfied with the results, and I was fired from that position. Since then, and a couple of washing machine purchases later, that same supervisor is still in charge of laundry. Thus, this weblog post is being written as a spectator to the washing process, and not as an active participant in it.

What does environmentally friendly clothes washing look like? At one time, say, until minutes before starting to write this post, I thought it was all about energy savings. Lower temperatures used less hot water. Now, I find that there are other considerations. A University of Leeds in-house article points to research on this topic.

Lucy Cotton, Adam S. Hayward, Neil J. Lant & Richard S. Blackburn, have written an article, “Improved garment longevity and reduced microfibre release are important sustainability benefits of laundering in colder and quicker washing machine cycles”, that appeared 2020-01-14 in Dyes and Pigments. The article’s abstract can be found in the last paragraph of this weblog post.

Clothes and bed linen have to retain their integrity: neither falling apart, nor sending microfibres into waste water, nor sapping textiles of their colour, nor shrinking. For decades now the washing temperature chez McLellan has been set to 50C, unless there is some specific reason for decreasing/ increasing it. The most common reason for decreasing the temperature, is that the laundry load consists of garments made from wool. These items are washed at 30C. We use Milo, a laundry liquid, for wool (and silk) textiles. We use Neutral Colour, a laundry powder, for everything else. One reason for increasing temperature could be an attempt at stain removal.

A Guardian article about the research, explained that 25C was selected as the working temperature, because that is a common inlet temperature for water in washing machine in England – the natural, unchilled and unheated temperature at which the water enters the drum. I am looking forward to gaining some empirical data on Norwegian inlet temperatures. Currently, my estimate is that they are closer to 10C. A post will be written after data has been collected and analysed, with updated information.

Cotton’s research did not test cleanliness at different temperatures. Instead, it examined the release of dye (desorption) and microfibres from a range of consumer clothing. So, the pesky question remains: Can cleanliness happen in a cold, quick wash?

Cleanliness has a social and cultural dimension beyond the requirements of hygiene for practical purposes. Numerous internet sources are quick to state that higher washing temperatures improve cleanliness, but there is seldom any empirical data associated with it. There seems to be a common expectation that cleaning will not only remove dirt, but also kill microbes. Some people may expect textiles generally, and clothes especially, to have a pleasant odour, others may want textiles to be odour neutral. Some may even expect a miracle and have white (or more correctly, some version of off-white) whitened/ lightened/ bleached.

Yet, excessive cleanliness may not be a virtue. The hygiene hypothesis, developed by David P. Strachan holds that environmental microbes help develop the immune system; the fewer microbes people are exposed to in early childhood, the more likely they are to experience health problems in childhood and as adults. So, it might be a good idea to reduce washing temperature, to avoid killing so many microbes.

However, it may be suitable to wash clothes and bed linen at higher temperatures when people have been sick with contagious diseases, but to use lower temperatures more generally. The instructions on Neutral Colour specifically state that 60C should be used for washing bed linen, if the user is allergic to dust. The instructions on Milo state that both 40C and 30C can be used.

In an attempt to get empirical data on the relationship between cleaning effectiveness and washing temperature, one article explained the futility of the effort. “No more washing: Nano-enhanced textiles clean themselves with light.” Researchers at the Royal Melbourne Institute of Technology (RMIT) University in Melbourne, Australia, have developed a cheap and efficient new way to grow special nanostructures—which can degrade organic matter when exposed to light— and to incorporate them onto textiles. They are working at producing nano-material enhanced textiles that can spontaneously clean themselves of stains and other dirt when exposed to light, artifical (as in lamp) or natural (as in the sun).

Then, Wikipedia writes: “Animal studies indicate that carbon nanotubes and carbon nanofibers can cause pulmonary effects including inflammation, granulomas, and pulmonary fibrosis, which were of similar or greater potency when compared with other known fibrogenic materials such as silica, asbestos, and ultrafine carbon black. Some studies in cells or animals have shown genotoxic or carcinogenic effects, or systemic cardiovascular effects from pulmonary exposure.” It is definitely a hint that relying on nanoparticles, may not be the way to go.


Domotics, or household automation, is defined in an earlier weblog post. The main concern there was with room controllers. However, domotics intersects many different areas. Its early history, began with labour-saving machines/ devices, frequently electrically powered. Thus, initial advances were dependent on electric power reaching the houses of consumers.

In this post, laundry represents a very specific yet important application of domotics. Most people have a concern about the cleanliness of their textiles, but there needs to be a middle ground. People can be too slovenly or too finicky. Neither extreme is particularly good.

It can be difficult to date the first washing machine. Progress and significant developments occurred in 1691/ 1767/ 1862/ 1904/ 1937, depending how one defines a washing machine, and one’s expectations from it. However, it is not until the late 1940s, that one finds machines vaguely similar to today’s.

In Europe, washing machines have to meet an assortment of standards including 1. washing performance (A to G) 2. spin drying performance (A to G), 3. energy consumption (A+++ to G), and 4. waste water filtration. In addition to these, products must also be labeled to show capacity (in kilograms), water consumption (in litres), noise while washing and noise while spining (both dB (A)).

Only washing machines with category A performance in terms of washing and spinning, are allowed to be sold in Europe. This is because of an unexpected consequences of the earlier focus on energy consumption: Reduced rinsing after washing saved water and energy, but left more detergent residue in clothes, which created health problems, especially for people with allergies or sensitivities.

The waste water filters ensure that hazardous chemicals are not improperly disposed of, or allow feces and other waste to enter the washing machine with back-flow through the waste water line.

Most washing machines in Europe are connected only to cold water, which after filling uses internal electrical heating elements to heat the wash water, to 95C, if desired. This may be useful in certain situations, either to kill pathogens, or to improve detergent cleaning action. These machines can use detergents formulated to release different chemical ingredients at different temperatures, allowing different type of stains and soils to be cl eaned as the water is heated.High-temperature washing uses more energy, and may damage fabrics, especially elastics.

Temperatures above 40C inactivating biological detergent enzymes. Thus, if these are used, temperatures should be kept below 40C. Front-loaders used to need low-sudsing detergents, because the drum’s tumbling action caused over-sudsing and overflows. This is no longer an issue, if one reduces the quantity of detergent. This will not lessen its cleaning action.

Characteristics of some modern washing machines offer:

  • Delayed execution settings, with a timer to delay the start of the laundry cycle.
  • Time remaining indicator.
  • Predefined programs for different laundry types.
  • Rotation speed settings.
  • Temperature settings, including cold wash.
  • Child lock (some machines).
  • Microcontrollers have been used for timing processes since the 1990s. These are more reliable and cost-effective than electromechanical timers.
  • Touch panel displays have been in use since 2010.
  • LG Electronics invented a direct drive motor system in 1998, with the stator attached to the rear of the outer drum, with the rotor mounted on the shaft of the inner drum. It eliminates a pulley, belt and belt tensioner.
  • Electronically controlled motor speed.
  • Hydraulic suspension, with freely moving steel balls contained inside a ring mounted at the front and back of the to balance the weight of the clothes.

Other innovations include:

  • Water jets/ sprays/ showers and steam nozzles. These claim to reduce soil and reduce washing times. Water jets use recirculated water from the bottom of the drum.
  • Titanium/ ceramic heating elements claim to eliminate calcium build up and can heat water to 95C.
  • Automatic dispensers allow users to fill or replace tanks with detergent and softener but transfers dosage control to the washing machine.
  • Detergent dilution is used to prevent detergent from damaging fabrics.
  • Pulsators are mounted on a plate on the bottom of the drum. When the plate spins, the pulsators generate waves that help shake soil out of the fabric.
  • Mechanisms can be installed to remove undissolved detergent residue on the detergent dispenser.
  • Smartphones can be used to troubleshoot problems. LG Electronics LG’s approach involves sending signals that can be received by a phone. These signals are interpreted by an app. Samsung Electronics’ approach involves the user photographing the washer’s time display with a phone. The problem and steps to resolve it are displayed on the phone itself.
  • Some washing machines are Near-Field Communication (NFC) enabled. These allow automatic and fast connections, wireless data transfer and identification. Its downsides include limited throughput, limited range and potential security vulnerabilities.

Comparison of domestic washing machines. Front-loaders are usually considered better than top-loaders.:

  • Front-loaders usually have lower operating costs than top-loaders.
  • Front-loaders usually have a lower total cost of ownership compared to top-loaders.
  • Front-loaders tend to have more advanced features such as internal water heating, automatic dirt sensors and high-speed emptying compared to top-loaders.
  • Front-loaders usually use less energy than top-loaders.
  • Front-loaders usually use one-third to one-half the water used by top-loaders.
  • Front-loaders usually use less detergent than top-loaders.
  • Front-loaders can spin at 1 400 RPM while top-loaders have a maximum speed of about 1140 RPM. Spin speeds and drum diameter determine the g-force working to removes residual water, allowing textiles to dry faster. This also reduces energy consumption if clothes are dried in a clothes dryer.
  • Front-loaders have longer cycle times than top-loaders, in part because top-loaders emphasize operational simplicity.
  • Front-loaders use paddles in the drum to repeatedly pick up and drop clothes into water for cleaning. Top-loaders use an agitator or impeller mechanism to force enough water through clothes to clean them effectively. Washing with a front-loader decreases fabric wear compared to a top-loader. One proxy for clothes wear is the amount of link found on a clothes dryer lint filter. Lint is largely stray fibers detached from textiles during washing and drying.
  • Top-loaders have greater difficulty cleaning large items, because these items may float on top of the wash water rather than circulate within it, and the agitator may damage delicate fabrics.
  • Front-loaders are usually quieter than top-loaders, because the door seal insulates noise. They usually have fewer problems with load imbalance. Top-loader agitators usually require the use of a mechanical transmission, which generates more noise than front- loader drives.
  • Front-loaders can be installed underneath counters. They can also be stacked with a clothes dryer to reduce their area usage.
  • Front-loaders have simple motor drives in contrast to top-loaders that use mechanical gearboxes with increased wear and maintenance needs.

There are some areas where top-loaders are better than front-loaders.

  • Front-loaders usually have a higher initial cost than top-loaders.
  • Front-loaders are more prone to leakage. On top-loaders, gravity keeps water inside the drum. Previously, front-loaders require a gasket/ seal on the front door. This door had to be locked while operating to prevent it from opening. Many modern front-loaders use so little water that they can be stopped mid-cycle for addition or removal of laundry. The water level is below the door level.
  • Top-loading washers are more tolerant of maintenance neglect.

Other comments

  • All washing machines should have access to a a floor drain or an overflow catch tray with a drain connection.
  • Front-loaders are more convenient for short people and those with mobility issues. Controls are front-mounted and the horizontal drum eliminates the need for standing or climbing.
  • Risers, often with storage drawers underneath, can be used to raise the height of a front-loader so that it is at the user’s preferred heigh level.

Combined washer dryers, provide washing cycles and drying cycles in the same drum.

  • The need to transfer wet clothes from a washer to a dryer is eliminated.
  • It encourages overnight cleaning, which may help optimize power usage during low priority periods, but may increase the risk of fire.
  • Drying uses more energy than using two separate devices, because a combo washer dryer not only must dry the clothing, but also needs to dry out the wash chamber itself.
  • A combo machine can be fitted into the same space as a single machine, allowing it to be used where the lack of space is an issue.
  • The washer may have a larger capacity than the dryer, decreasing their functionality.

A laundry centre is an appliance with two drum units. It is found in two varieties, one where the dryer and washer are beside each other, and the more common situation, where the dryer sits on top of the washer. Laundry centers have a single control panel for both units.

The Future

In the course of the coming years, I hope to look at many different household appliances, from a Domotics perspective. This includes revisiting washing machines, when I have learned more about how they will be operated. My most obvious limitation is my status as spectator, rather than participant, in the laundry cleaning process. To remedy this, I am going to ask reader with insights into washing clothes, to answer some open-ended, even vague, questions. These are preferred because they might actually lead to some insights.

  1. Tell me something/ anything/ everything about washing textiles that you want me to be concerned about!
  2. Tell me about yourself. What is your status? Participant/ Spectator/ Other (please specify). Are you female/ male/ non-binary/ a human bean? What is your approximate age? Have you ever had training to wash textiles? For example, did you learn anything at school about it?
  3. How are your laundry facilities organized? A separate laundry room/ part of a bathroom/ part of another room/ other (please specify). What type of equipment do you use for washing? Comments. What type of equipment do you use for drying? Comments.
  4. Do you use services outside of your residence to clean textiles? What services do you use? How often? Why? What are the challenges?
  5. Do you use the services of non-family members, who come into your residence to clean textiles? What services do they provide? Why do you use them? What are the challenges of using them?
  6. What are your textile washing objectives? Do any of them involve general dirt removal, stain removal, killing microbes, eliminating odours, adding odours, neutralizing odours, preventing shrinkage, preventing colour bleeding, increasing garment longevity, reducing microfibre release in wastewater, reducing operating costs, reducing energy consumption?
  7. What are your textile washing behaviours? For example: What temperature settings do you use? What cleaning chemicals do you use? What additional chemicals do you use? Do you have any special procedures used in particular situations?
  8. What would you like to automate in terms of laundry processes? Some choices include: start time, finish time, determining washing cycle, determining detergent quantities, automatic dosing of chemicals, other (please specify).
  9. Washing machine characteristics. Do you use a front-loader or top-loader, please specify brand, model and approximate age (I will try to find out other details from that). What do you like about this machine? What do you dislike about it? When do you expect to replace this machine? What do you think will be the reason for its replacement?
  10. Future washing machine characteristcs. What characteristics are missing in your current machine would you prioritize in your next machine? What characteristics are present in your present machine that you would avoid in your next machine?
  11. Did you want to tell me something else?

Abstract from Cotton et al.

The global impact of laundering clothing is significant, with high levels of water, energy use, and pollution associated with this consumer care process. In this research, the impacts of washing temperature and washing time on garment colour loss (dye fading), colour transfer (dye staining), and microfibre release were evaluated using retail consumer clothing. Significantly greater colour loss and greater colour transfer were observed for a 40 °C, 85 min wash cycle compared to cold-quick (25 °C; 30 min) cycle. Desorbing dyes were found to mainly be reactive dyes. From fundamental kinetic studies, it was observed that significant increases in both rate of dye desorption and total dye desorption occurred when increasing from 20 °C to 40 °C, but the difference in dye release between 40 °C and 60 °C was not as significant; the same kinetic trends were observed for dye transfer. Microfibre release was significantly greater for the 40 °C, 85 min cycle in comparison with the cold-quick cycle, and this effect continued with further washes. These results mean that reducing time and temperature in laundry could have a significant impact in terms of extended garment longevity and reduced dye and microfibre liberation into the environment, in addition to energy savings.

Clouds & Puddles

Clouds are not always cute. Sometimes they are threatening, with the potential to damage, injure and even kill. Inderøy, Norway 2015-08-11. Photo: Patricia McLellan.

This weblog post is written to help people gain a better understanding of a house/ home/ residential computer network.

The Xample family with mother Ada, father Bob, cat Cat and daughter Deb are going to serve as an example. Currently, the family has the following equipment. Both Ada and Deb have iPhones, but Bob has a Samsung phone. In addition, Ada uses a Mac laptop, Bob has an old Acer desktop machine, while Deb uses a Chromebook laptop, that belongs to her school. The family is connected to the internet with a router, and they have an old Canon printer.

Some basic vocabulary

Sometimes, language can be confusing. To communicate about computers, people have to use words the same way, or misunderstandings will occur.

Users are people. Admittedly, there could be situations where something other than a human is a user. For example, at some point in the future Cat might be able to activate a feeding station. That would make Cat a user.

A computer, frequently known as a device, consists of hardware and software. Hardware is made up of physical/ mechanical components. Yet, these components will not work without software, a collection of instructions and associated data, that provide services.

Software capable of doing something is called a program. A computer program that is running/ working is usually referred to as a process. Software is written in a computing language that humans can read, and programmers can understand. This source code is then translated into machine code that the specific hardware on a machine can understand.

Operating systems are an important category of software. An operating system is the most fundamental program. It controls the functioning of the hardware and direct its operations. It manages the hardware including component parts, but hides the details from users. The Xample family, like most families, use several different operating systems. The iPhones use iOS, the Samsung phone uses Android, Ada’s Mac laptop uses macOS, Bob’s desktop uses Windows 7, Deb’s Chromebook laptop uses ChromeOS. Both the router and the printer also have their own special operating systems.


The term network can be used as either a noun or a verb. Begin with the verb, to network. This is a situation where two or more devices are able to exchange information with each other. The noun network refers to the sum of devices that are connected together. When networking, each connected device is referred to as a node. In the above case, an end node is connected to a network node, the iPhone and the router, respectively.

Nodes are connected to each other using data links. These links may be wired or wireless. The most common type of wired link is the Ethernet cable. The most common type of wireless link is WiFi. While some houses have only WiFi links, there can be good reasons for using cabled links if there is an opportunity for it.

Nodes don’t need to have a direct connection to each other, to be part of a network. Thus, one node could be located in Bergen, another in Detroit, and a third in New Westminster. This is an example of a wide area network (WAN). If the nodes are all located in the same cluster of buildings it is a local area network (LAN). For example, there could be several nodes inside a house, but one in a garage and another in a shed.

Computer professionals often use the terms client and server to describe a computing model. These are confusing terms. Fortunately, most people do not need to use them. The important thing to know is that a client either does local work or requests an external service. A server either provides that service directly to a client, or supervises an external supplier working on behalf of a client. Both terms can refer to either hardware or software. Focus on the software to understanding what is happening.

To help the Xample family transition to a network suitable for them, we are going to look at four challenges facing the family.

Challenge #1 Sending an email with an attachment

Ada has struggled for the past year to knit herself a sweater. It is finally finished, and she has taken a photo of it with the camera on her iPhone. She wants to send a copy of the photo to her brother Ely.

When Ada uses her phone to write an email, she is using an email client that is built into the iPhone. This client also allows her to attach the photo. When it comes time to send the email and its attachment, Ada uses an email server built into the iPhone that allows it to use the router to send out and receive emails.

In this example, there are two communicating devices, Ada’s iPhone and the family router. There is a network, even if it is small, simple and temporary. The two devices are connected using WiFi,

The router breaks both the email message and the photo into data packets. Each packet is equipped with a coded form of Ely’s email address. To find out where to send information, the router looks up an address using a routing table. If Ada receives an email from someone, the router will reassemble incoming data packets so that these can be understood. At home, most people use a digital subscriber line (DSL) or cable router connected to the Internet through an Internet service provider (ISP).

A DSL router typically integrates a modem. A modem sends packets of data across telephone lines, TV cables or optical fibers. A modem, by itself, does not provide the functions of a router.

Challenge #2 Printing

Ada wants to take a copy of the photo on her next visit to her grandmother Fay (1919 – ). Fay is not computer literate, but likes to decorate the walls of her room with photos. Before looking at what is happening in detail, we are going to learn a few more terms. To print a letter on paper, a print server will coordinate the printing process.

The main challenge with the family Canon printer is that it is so old that it doesn’t have any WiFi connection and won’t connect directly to the iPhone.

Ada connects her iPhone to her MacBook using the iPhone’s charger cable. She plugs the charging end into the iPhone, and the USB end into the MacBook. She then opens her Mac Photos app on her Mac laptop, clicks on Import, selects the photo she wants to transfer, clicks on Import (#) Selected, then finally clicks on Albums. Now the photo is on her laptop, and Ada can disconnect the charger cable.

To print the photo, Ada takes a USB cable, permanently attached to the printer, and plugs the other end into a USB port on her computer. Using a printer program and drivers, previously installed on her laptop, she can now print the photo. By plugging in the cable, Ada has once again set up a small, simple and temporary computer network. This time, it consists of the MacBook laptop and the Canon printer.

Challenge #3 A Permanent Network

Deb has her bedroom upstairs. If she wants to use the printer she has to take her Chromebook downstairs to attach it into the printer, using a USB cable. This is inconvenient. Most individuals/ couples/ families need system resources that can be shared by all/ many/ some users effortlessly. The basis for a permanent network may already be in place with the WiFi capabilities that are built into most domestic routers.

WiFi is a set of standards that allow devices to communicate with each other wirelessly. Devices that can use WiFi include desktops, laptops, smartphones, tablets, smart TVs, printers, digital audio players, digital cameras, cars and even drones.

Some families may consider replacing their printer with one that has WiFi capabilities. An alternative approach is to keep the printer, but to invest in a Network Attached Storage (NAS) server. A NAS can act as a print server, letting approved users print on a common printer.

Equally important, it can also act as a file server, so that common files can be stored in a central place and used by everyone. Such files include media files: video files, audio files, e-books; family photographs, and documents used by the entire family.

Everyone in the family will have to become users of the NAS, with their own log-in. Be sure to add an additional user, called Guest. Not all users are treated equally. Users have to log their client devices onto the system with a user name and a password, or some other approved form of identification. In this way, random visitors are prevented from accessing the server and its resources, without permission. Guest will typically be able to access the internet, but not able to access files on the NAS or use the printer.

A NAS can also backup personal files. These backups can be encrypted and password protected,so that they are unaccessible to others.

The Xample family decide that a QNAP TS-251A best suits their needs. They equip it with 4 TB of storage, which they regard as adequate for their needs. The printer can now be permanently connected to the NAS using a USB port, given access to users. Many printer drivers are instantly available, although older printers may require some effert to download appropriate drivers. If the printer is compatible with the NAS, it will display a message to confirm that the printer is connected.

Challenge #4 Clouds & Puddles

The Xample family now have 3 smartphones, 2 laptops, 1 old desktop, 1 printer, 1 router and 1 NAS. The NAS can function as a print server and a file server. It is also a media centre, serving videos and audio.

Computer hardware manufacturing companies are always keen to describe old products with new names. They are always looking at ways to make their rather dull equipment seem more important than it actually is. Edge and cloud computing are two such names.

An edge computer, in dataspeak, is a local server device at the edge of the internet, hence the term. Many will find it difficult to distinguish an edge computer from any other server, because almost everything today is connected to the Internet. However, in years past, many local servers were only connected to local devices using a local area network (LAN) typically wired with Ethernet cable. There was no connection to the outside world.

The cloud, in dataspeak, refers to someone else’s server. Companies that offer cloud services to the public often claim that they do the heavy lifting, storing and safeguarding data. This is not always the case. Sometimes they lose data. Sometimes they lend data to others. They might even keep a copy of it, when you ask to have it back. The misuse of data held in trust, may have economic as well as other consequences. Adobe, Amazon and many other companies are very keen for consumers to visit a nearby cloud, and use software as a service. This is the most profitable for them. Using a cloud can be expensive.

For a short period, just after cloud computing came into vogue, it became fashionable to name non-cloud servers after bodies of water. Large businesses might refer to their in-house servers as lakes. Referring to a server at home as a lake verges on the pretentious. Modesty dictates referring to smaller bodies of water: a personal (puddle) server, a nuclear family (pool) server or an extended family (pond) server.

Fun Assignment: The reader is asked to distinguish a carbon based error from a silicon based error. Assistance with this problem can be found here.

Weblog Ethics

Wrongful actions committed by criminal justice professionals, who are black or people of colour in crime drama series. Source: https://colorofchange.org/

Even weblogs must have ethical standards.

Jim Lehrer (1934 – 2020) constructed a list of 16 Rules of Journalism, printed in italics at the beginning of the paragraphs below. These were later reduced to nine rules, marked with an *. These rules were copied from Kottke, who comments on them in general, and points to their original sources. I am using them as a starting point for my own personal reflections on weblogging. It does not mean that I favour these rules over other rules, for many have infuriated me. Others, not so much. Some rules have not been commented upon. Others have. See, especially, rule #15.

  1. Do nothing I cannot defend.* Coming first and with an *, it could be an important rule, but it grates. It is defeatist, starting with the negative (do nothing) rather than the positive (so something). Even the term defend points in two directions. Is Lehrer concerned about protecting something? or is it about showing support? My replacement would be: Promote causes that you endorse. Cause could refer to a principle, ideal, goal or movement to which a person is dedicated, or the end/ purpose for which a thing is produced, or even something broader still, such as the general welfare of the planet/ humanity/ a more restricted group/ person. Endorse includes a range of support (middle ground), from approval (weaker), to sustain or defend (stronger).
  2. Do not distort, lie, slant, or hype. This is a difficult rule to follow, especially the slanting. A slant is a perspective on a problem. All events have to be viewed from some perspective, even if they aren’t acknowledged. Where does slanting stop, and hype and/or distortion begin? How much distortion, hype or slanting does it take, before the result is considered a lie? There are no easy answers. One reason for weblogging is to present alternative opinions, especially those that are not supportive of the mainstream, which for me consist of a libertarian perspective on the economy, and a conservative perspective on social life, that are found/ distorted/ lied about/ slanted/ hyped in commercial media.
  3. Do not falsify facts or make up quotes. Quotations and other attributions of thought are difficult. In part, it comes from the inability of some people to speak/ write succinctly enough. Often, there is a need to re-state the essence of a person’s opinion, without distortion. At another level it also reveals a major challenge with journalism and its focus on individuals, rather than systems. One criticism of journalists is that some seem more interested in a subject’s passion or conviction, rather than the truth of their statements.
  4. Cover, write, and present every story with the care I would want if the story were about me.* Washington Post reporter Felicia Sonmez (1983 – ) tweeted a link to an article about the 2003 rape accusation against Kobe Bryant (1978 – 2020), who died on 2020-01-26 in a helicopter accident. Sonmez was subsequently harangued and threatened, her address posted publicly, and her employer placed her on administrative leave. Bryant issued an apology where he made clear he believed the woman when she said she did not feel their encounter was consensual. The Median article describing the Sonmez situation, reasons that that public relations were more important to the Washington Post than Sonmez herself. It wonders why rape victims would trust the Washington Post with their stories if they think the paper is more concerned with appeasing an online mob than holding powerful men to account? It concludes that a powerful publication silenced its female reporter for tweeting about rape. Lehrer’s rule seems to suggest he would prefer people not to write about rape, or any other uncomfortable subject, at least when the alleged perpetrator is a celebrity.
  5. Assume there is at least one other side or version to every story.* One of the reasons I have stopped reading a particular local newspaper, is that – from my perspective – it covers stories by focusing on one single person/ perspective, and allowing that one person to frame events. There seems to be no balance, until later – perhaps – when a second perspective is described, that is 180 degrees away from the first. Even then, it is difficult for the second party to address issues, because they have already been framed, possibly detrimentally.
  6. Assume the viewer is as smart and caring and good a person as I am.* Radio, television, newspapers (and more) are mass media, sending out their stories to thousands, if not millions of listeners, viewers and/ or readers. The audience of this weblog is entirely different. It currently consists of 32 other people. Each of these people I know personally, even if there are some that I have never met in person. Others, I may not have met for over fifty years. I have also stated that if this weblog has an audience of more than 100 people, I will have failed at my goal. I have no desire to be famous, or to be popular. Perhaps Bernie Sanders (1941 – ) has expressed it best. Responding to a comment by Hillary Rodham Clinton ( 1947 – ) that no one likes him, Sanders replied, “On a good day, my wife likes me.” This weblog is not trying to influence anyone, apart from a very select group who are (hopefully) equally smart, caring and as good as I am. It is encouraging people to forget mass-market social media, and to engage with a limited number of real friends on issues that are of importance to that small group of people.
  7. Assume the same about all people on whom I report.* I presume this rule is actually stating, that journalists must assume that the subject of a story is as smart and caring and good a person as the journalist reporting. This makes an assumption that stories are about people. Many of my stories are about technology, sometimes its failings, at other times it successes.
  8. Assume everyone is innocent until proven guilty. In its editorial on 2020-01-24, Logisk brist = Logical Deficiency, the Inderøyning newspaper takes up the legal situation of a Norwegian woman and her two children, who have been returned to Norway from Syria. The problem is that leading politicians have pronounced the woman guilty of terrorism, despite the lack of any legal judgement against her, in violation of the Norwegian constitution. Her return to Norway has even led to the Progressive Party, leaving the government. In social media, including weblogs, it is far too easy to defame people who must be presumed innocent. It is my understanding that no court of law has found this woman guilty of anything.
  9. Assume personal lives are a private matter until a legitimate turn in the story mandates otherwise.* When I initially read this statement, my mind turned to social media, and how it is encouraging precisely the opposite of this rule. For even the most intimate details of a person’s life are exposed and commented upon.
  10. Carefully separate opinion and analysis from straight news stories and clearly label them as such.* This rule shows by example, the challenge of finding suitable rules. I think I understand all of the words in the rule until I get to the phrase straight news stories. It grates. Even if journalists use the term story, it is too close to the concept of fiction for my liking. I suspect a news story is a spicier version of a sequence of news facts. Since the adjective straight is being used to modify news story, I am left wondering what other varieties can be found. When I look up straight in a dictionary I find 19 different meanings, including not curved and heterosexual. Fortunately, it also provides me with a better understanding of its journalistic meaning: written or to be written in a direct and objective manner, with no attempt at individual styling, comment, etc. If I were to help Lehrer, by re-writing the rule for him, it would be: Separate and label facts, opinions and analyses.
  11. Do not use anonymous sources or blind quotes except on rare and monumental occasions. No one should ever be allowed to attack another anonymously.* While sources are sometimes lacking in this weblog, when people are mentioned, I try to put in their name as well as their year of birth and death, to try to put that person’s experiences into context. The same is also true, with respect to the first publication date of a book or article. Unfortunately, not all C.V.s contain essential information, such as year of birth. There are times when I feel I should go further, and include country of birth, or at least residence. L. P. Hartley (1895 – 1972) wrote in The Go-Between (1953), “The past is a foreign country; they do things differently there.” It is often difficult to understand what has motivated people. Even more difficult if the context of their life is missing. Personally, I am a pacifist, and refuse to use weapons. Yet, both of my parents, Edgar (1906 – 1991) and Jennie (1916 – ) served in the Royal Canadian Air Force during the second World War. While I have been able to condemn almost all wars since then, I still have difficulties understanding WW II, and passing judgement on its participants.
  12. Do not broadcast profanity or the end result of violence unless it is an integral and necessary part of the story and/or crucial to understanding the story.
  13. Acknowledge that objectivity may be impossible but fairness never is.
  14. Journalists who are reckless with facts and reputations should be disciplined by their employers. This is a very naive statement, given that much of the media is owned by entrepreneurs wanting to promote a particular political perspective. The right-leaning (Kieth) Rupert Murdoch (1931 – ) through his News Corporation, owned over 800 companies in more than 50 countries, with a net worth of over $5 billion in 2 000. In other ages, there have been other media moguls with other priorities. William Randolph Hurst (1863 – 1951) favoured the working class, who bought his papers, and denouncing the rich and powerful. Today, Mark Elliott Zuckerberg (1984 – ) has become infamous for Facebook’s role in allowing Cambridge Analytica to harvest personal data from millions of Facebook profiles without their consent and using it for political advertising purposes.
  15. My viewers have a right to know what principles guide my work and the process I use in their practice. Change viewers to readers, and the statement should be true of every serious weblog. Thus, I am curious to know what readers believe should be the principles followed in this weblog. Readers with opinions are encouraged to comment. Those reluctant to do so publicly, are encouraged to send a confidential email. While I will read and evaluate all material sent, this does not mean that I will incorporate it in any final rules for Brock’s weblog.
  16. I am not in the entertainment business.* That is a debatable point. Everything related to the media can be considered entertainment, even if some regard themselves above it. Much of the harm initially done there, is subsequently amplified by webblog posts. Take television crime drama, as an example. In Change of Color’s report, Normalizing Injustice, a disproportionate number of wrongdoing criminal justice professionals are black or people of colour, as shown in the table at the beginning of this weblog post. This report reminds people that “the crime genre glorifies, justifies and normalizes the systematic violence and injustice meted out by police, making heroes out of police and prosecutors who engage in abuse, particularly against people of color.” Misconduct is often presented in a way that normalizes it, making problematic characters seem good and their wrongful actions justified. Fiction is not just fiction, and entertainment is not simply entertainment, both are tools that shape attitudes. Entertainment cannot be ignored, for it can be the face of oppression.

This marks the end of Lehrer’s rules. What do readers think should be in a set of rules that should apply to all weblogs? In addition to these, what other rules should apply specifically to Brock’s weblogs?

Devices Future

Volkswagen and D-Wave Systems have used quantum computing to find optimal routes, as illustrated here in Lisbon, Portugal, and available as an app near you. (Photo: Volkswagen)

… and the answer is, everywhere.

Now for the question, where do people want to use computing devices?


After trying to collect and interpret validated statistics, I have given up and present some numbers than might approach something meaningful and coherent. Some are based on information collected by Simon Kemp, dated 2019-01-31. Other bits come from Wikipedia, such as this article, along with a variety of other places with assorted dates.

With a world population of 7.7 billion people, there are over 5 billion handheld devices, the vast majority also referred to as mobile phones, increasingly smartphones, although they do much more than connect people using voice communication. It would be much more honest to eliminate any reference to phone in the description. The German Handy or the French Portable, are both better. Other devices in this category include tablets, and similar devices lacking keyboards. Regardless, Android operating system variants clearly and increasingly dominate, with at least 75% of market share, with Apple’s iOS declining market share taking most of the remainder. It remains to be seen if Huawei will be able to introduce a viable alternative to Android.

There are two important characteristics that distinguish handheld devices from larger personal computers. They are the large screen size and the use of a keyboard input device. Minor differences also include the use of a mouse or some other pointer, They are often referred to as laptop and desktop machines. In terms of the world, this is small segment of machines compared to mobile devices, with its importance decreasing. Part of the reason for this decline is their inability to be used everywhere.

There is general agreement that the billionth personal computer shipped in 2002, and that there were one billion such computers in operation in 2008. The dispute is how many are in use now. Some are looking for a magic number of 2 billion, but 1.5 billion units is far more likely. Windows will be installed on at least 75% of machines, MacOS on, say, 13% (which to me seems high), ChromeOS on 6% (at least in the US, and higher than I experience in Norway) and Linux on 2%. The 2019 Stack Overflow developer survey gives very different figures on what is found on machines used by computing professionals. In round numbers: Windows on 45%, MacOS on 30%, and Linux on 25%.

Another category of computer is the embedded device. One essential aspect of these is the electronic control unit (ECU). Domotics refers to home robotics. It includes all aspects of smart home technology, including sensors that monitor the environment and actuators that activate controls. These include temperature, lighting and security. However, it is pervasive, found everywhere from electric toothbrushes, to toasters and every other form of kitchen machine. Today, even a lightbulb can be considered an ECU. A typical smarthouse may contain hundreds of these devices.

The vast number of ECUs expected, plus its vulnerability in terms of security, means that WiFi can only be a temporary solution. While communication can be built on top of 120/240 V AC circuits, most devices, including LED lights, actually use low voltage DC power. Anyone building something new should be installing Ethernet cable 6A at a minimum, with connections to every room. Power over Ethernet, (PoE) can then provide DC power to almost everything needed.

I expect clothing will soon include embedded devices, so that personal data can be continuously collected and monitored. In Sweden, I note that several individuals have voluntarily inserted RFID devices into their bodies, so that they can use these to identify themselves, rather than relying on PIN codes. Unfortunately, it is probably only a matter of time before these devices become mandatory.

Embedded devices are also found in cars where even the most primitive contain 25 – 35 ECUs. More luxurious models may have 70 or more ECUs. Hopefully, autonomous vehicles will soon be on streets near you. The last thing this world needs is a nut behind the wheel, especially one that feels provoked into road rage at the slightest offence. Electric vehicles are already here, with Tesla’s innovations leading the way. In Norway, there will be no opportunity for people to buy fossil fueled vehicles (including hybrids) after 2024. Everything will probably be battery electric, as an explosion at a hydrogen fueling station has dimmed everyone’s interest.

Command and control (C2) is defined by Marius Vassiliou, David S. Alberts and Jonathan R. Agre in C2 Re-Envisioned: the Future of the Enterprise (2015) as a “set of organizational and technical attributes and processes … [that] employs human, physical, and information resources to solve problems and accomplish missions.” (p. 1) This definition can apply to individuals, households, organizations, small businesses, large enterprises or even the military. One major challenge has been the tendency of large manufacturers of ECUs to consider just their own product range, and to make controllers for these and only these. This is not a viable solution. Our household has opted for the most inclusive solution, found in Home Assistant.

Miniaturization will continue into the future. I am uncertain about the future form factor of personal devices/ phones. Asked if they will shrink to wristwatch size or remain about the size they are today? Today’s form factor wins. Yes, one can imagine screen technology being built into glasses, or wrist watches, but will it happen? It will be interesting to see what has happened in 2040 and beyond.

In terms of PCs, they could be doomed to extinction. Physically smaller personal devices will be capable of doing everything PCs do. However, there may be situations where a person may want a larger screen, a keyboard and a pointing device. So the personal device will have to interact with these. I am not certain when voice control will replace the keyboard. When I first studied computing, in the mid-1970s, 1980 was even considered a target date for its replacement. However, that was based on people going from card punches to something else.

In terms of servers, one can also envisage a household having something the size of a small media centre, perhaps 100 x 100 x 50 mm (4″ x 4″ x 2″) which is about the size of our Asus PN 40 media player. At the current rate of miniaturization, it should be able to hold at least 100 TB by 2040. One could ask why anyone would need so much storage capacity, but today everyone seems capable of using every last byte of storage they have, and I see no reason for attitudes to change. Computers will be used in new areas because people have the processing power and data storage capacity to do it.

Perhaps the greatest change will come as quantum computing matures. Quantum computing is real. It allows computations to be made in seconds that would take a conventional supercomputer considerably longer. Google claims that its Sycamore processor with 54 Qubits, has achieved quantum supremacy, and is the most advanced quantum computing processor in the world, capable of processing in 200 s, what a Summit supercomputer would use 10 000 years to accomplish, making quantum computing 1 577 880 000 times faster. IBM has countered this, stating that it would only take 2.5 days, making quantum computing about 1 000 times faster. Regardless, quantum computing will provide faster calculations.

With my origins in Vancouver/ New Westminster, and with some of my most positive learning experiences at the British Columbia Institute of Technology, I will end this post by mentioning its Burnaby neighbour, D-Wave systems. They announced in 2019 their next-generation Pegasus quantum processor chip, the world’s most connected commercial quantum system, with 15 connections per qubit, and with more than 5000 qubits, to be available in mid-2020.

Stavanger Airport Parking Garage Fire: A tidbit

Thermite RS1-T4 (photo: Howe & Howe Technologies)

On 2020-01-10 a fire broke out in a parking building at Norway’s Stavanger Airport. There were no injuries to people. However, much of the structure collapsed, including ramps to upper stories, because of structural damage caused by intense heat. Fire trucks could not enter the structure because of its low ceiling height. Because of its open walls, it was not, and was not required to be, equipped with a sprinkler system. An estimated 200 – 300 vehicles were destroyed in the fire, but about 1 300 vehicles were trapped in the building. It was initially reported the fire started in an electric vehicle. However, the fire started in a recalled diesel-powered 2005 Opel Zafira. The car was recalled after a similar fire in Cork, Ireland 2019-08-31, damaging about 60 cars in another parking structure.

Fake news, has resulted in some places in Norway banning electric cars from parking in their structures, although this is being contested by The Norwegian Electric Vehicle Association. It has sent out letters about this situation, the latest on 2020-01-21. The Norwegian Directorate for Social Security and Preparedness (DSB) states that electric cars rarely burn, but when that happens, the fire has a different course than fire in a gasoline or diesel-powered car. The fire energy is smaller and develops more slowly, but the extinguishing work must be done in a different way and may take longer.

Nils-Erik Haagenrud, Fire and Rescue Chief in Rogaland, the county where Stavanger is located, wants the county to invest in a robot that can be put into extinguishing work, when crews have to stay away from a fire, physically. Rogaland has the longest subsea tunnels in Europe, with exactly the same problems as in the parking facilities. Oslo and Romerike use robots.