1.1. Advanced Power Management (APM/ACPI)

1.2. Power Management Unit - PMU (Apple PowerBook)

PowerBooks don't support the APM specification, but they have a separate protocol for their PMU (Power Management Unit). There is a free (GPL) daemon called pmud that handles power management; it can monitor the battery level, put the machine to sleep, and set different levels of power consumption. It was written by Stephan Leemburg <stephan at jvc.nl>, and is available from PPC distribution ftp sites (e.g. ftp://ftp.linuxppc.com/contrib/software/Utilities/System/). There is also an older utility called snooze available from the same sites that just puts the PowerBook to sleep.

1.3. Turn Monitor off, use Keyboard LEDs

There are some tools which allow to get information from your computer without using the monitor:

• bl : Blink Keyboard LEDs

• blinkd : "Blinks keyboard LEDs for an answering machine or fax machine. Blinkd is a client/server pair, that lets the keyboard LEDs blink, indicating things like the number of incoming voice calls in the voice box or incoming faxes in the spool."

• mailleds : Shows new mails with the keyboard LEDs, mailleds is a quiet, unobtrusive way to signify that you have new mail: a user daemon to blink LEDs when there is new mail.

• tleds : Blinks keyboard LEDs indicating TX and RX network packets. They blink Scroll-Lock LED when a network packet leaves the machine, and Num-Lock LED when one is received.

1.4. Screensavers

Do they only prevent the screen from being burned in or do they save power, too?

Some recommendations from Wade W. Hampton: Screensavers usually display graphics, look for ETI, or perform other tasks. When using your screensaver in this manner, you may actually consume MORE power. For example a computer using XSETI as a screensaver might get far warmer (hence use more power) than when it was being used to edit a document or perform a compile. To really save power, and if your X server plus monitor supports it, use the dpms option of xset (see the manual page for xset). For example, to enable the DPMS (Energy Star) features of you X server: xset +dpms You may also manually change the mode of your X display:

xset dpms force standby xset dpms force suspend xset dpms force off

AFAIK a CRT consumes on the order of 25 percent more power when displaying a plain white screen than displaying a plain black screen. So, a screensaver that's mostly black can help save power, even if it doesn't actually use DPMS to power down the screen. Of course, one that's very bright and colourful, or that keeps the CPU running fast is not much help.

Some screen saver programs:

• The purpose of xscreensaver is to display pretty pictures on your screen when it is not in use, in keeping with the philosophy that unattended monitors should always be doing something interesting, just like they do in the movies. The benefit that this program has over the combination of the xlock and xautolock programs is the ease with which new graphics hacks can be installed: you don't need to recompile this program to add a new display mode, you just change some resource settings. Any program which can be invoked in such a way that it draws on the root window of the screen can now be used as a screensaver without modification. The programs that are being run as screensavers don't need to have any special knowledge about what it means to be a screensaver.

• LockVC is a console-locking-program combined with a starfield screensaver. Executing LOCKVC on a virtual console brings up a starfield that starts to rotate around all three axes.

1.5. Energy Star Label

Robert Horn <rjh at world.std.com> wrote: "

I had a chance to discuss Energy Star with the designers of desktop printers. They confirmed that the allowable stand-by power targets depend on the device, and they only knew their targets. But they made some other interesting comments:

• Energy Star ratings lead to significant operational power savings. Timer based power savings are the exception. Most savings come from designing in power on demand with low leakage drivers. For example, using stepper motors with low leakage current instead of high leakage.

  This savings is both from individual designs and from the resulting demand for low leakage products causing better and cheaper low leakage product designs. The old-style (e.g. typewriter) design with one motor (always on) and various clutches is no longer the least cost.

• Energy Star was good organizational engineering. It never required designers to compromise quality or performance, which made it much harder to argue against design changes to reduce power consumption while idle. Since most of the savings begin the millisecond that parts stop moving, these savings are considerable.

• The power ratings on PC's are a safety rating, not a usage rating. So the 235W and 300W power supplies that commonly found in PCs are specifying their safety limits. Actual full power usage is much less, typically 20-30 percent of the safe limit. The designers also noted that it is actually difficult to measure the power consumption of a switching power supply. You need to use specially designed power meters. The regular AC meters are designed for motors, and are rather inaccurate for switching power supplies.

1.6. Miscellaneous Power Saving Techniques

Linux halts the CPU in the idle cycle to further reduce power consumption. Early reports of OS/2, Win3.1/95, NT, and Linux showed Linux to use far less power than DOS-based O/S's that spun in the idle loop and consumed power -- this may have changed hence it would need research to validate.

Most Linux-users tend to leave their computer on for years whenever possible. However, several modern BIOS's support an unattended powerup, and with cron you can even do an unattended shutdown. No need to leave the computer on night after night.

3.1. Fan

• libsensors0 is a library to read temperature/voltage/fan sensors

• lm-sensors "Kernel drivers to read temperature/voltage/fan sensors. This is a module for reading the temperature/voltage/fan sensors in Linux via the LM78/79 chip and possibly sensors on the SMBus (System Management Bus, usually found in P6 and P-II systems). The LM80 and a LM78-clone called W83781D are also supported." http://www.lm-sensors.nu/

• ACPI, see APM chapter

3.2. Harddisk

The noise of the hard disk can be very disturbing, see man hdparm to reduce the spin of the disk.

3.3. Speakers

For the console setterm -blength 0 and for X xset b off turns the bell off. See also PCMCIA-HOWTO, and much more details in the Visible-Bell-mini-Howto by Alessandro Rubini.

4.1. Printing of Drafts / Multiple Pages on One Sheet of Paper

Use psutils package to put more than one page on one sheet of paper. This collection of utilities is for manipulating PostScript documents. Page selection and rearrangement are supported, including arrangement into signatures for booklet printing, and page merging for n-up printing.

Often HTML pages are not optimised for printing. You may use html2ps, a HTML to PostScript converter, to print HTML pages. "This program converts HTML directly to PostScript. The HTML code can be retrieved from one or more URLs or local files, specified as parameters on the command line. A comprehensive level of HTML is supported, including inline images, CSS1, and some features of HTML 4.0."

Or you may use mpage to print 2 up or 4 up (PS documents or ASCII text). This may be used to save up to 50 percent or more of your paper.

4.2. Double Sided Printing

One important way to save paper is to print on both sides of the paper. Ben Woodard is working on a library called libppd that allows you to do this from standard Linux printing programs (along with other printer tweaking, but duplex printing is most important for paper saving.)

http://sourceforge.net/project/?group_id=1658 is the download page for the beta version, as well as for a modified version of lpr that supports this functionality.

mpage can do some of this as well. From the manual page:

-jfirst[-last][%interval]

Print just the selected sheets, specified by number, starting at 1. Here last defaults to the end of data, interval to 1. Thus -j1-10 selects the first 10 sheets, while -j 1%2 prints just the odd- numbered sheets and -j 2%2 prints just the even ones.

You can do double-sided printing, in two passes, as follows. If you use 3-hole punched paper, put it in the printer such that the holes will appear at the top of the page -- on the right as you pull out the printer tray, in our Laser writer II NTX. Print the odd-numbered sheets with

-j 1%2 ...

Note the number of pages it reports. (Only half this many will really be printed). When printing finishes, if mpage reported an odd number of pages, remove the last one from the stack, since there will be no even-numbered sheet to match it. Then arrange the stack of paper for printing on the other side. (If it's punched, the holes will now be on the left.) On our II NTX, the paper comes out blank-side up; replace it in the tray still blank-side up but rotated 180 degrees. For other printers, you figure it out. Now print the even- numbered sheets in reverse order with

-r -j 2%2 ...

hoping no one else reaches the printer before you do.

Still missing are some explanations how to use a printer, which has a duplex (add on) device. Sorry I don't have such an expensive printer, so I can't check it yet.

4.3. Reading From the Monitor Instead From Paper

Or use less/xless/gless as a viewer instead of printing. You can view PostScript documents with gs and view PDF documents with either xpdf or acroread (from Adobe). Ask yourself, do you --really-- need a hardcopy each time you decide to print something out.

What are the reasons why people don't read from the monitor:

• Reading is slower up to 30 percent, see N.N.. The speed can be improved by better hardware (e.g. TFT display, greater screen, though this is against the other below to take smaller CRTs) and better display software (type-1, t1lib, truetype, freetype).

• Paper seems better organizable and more secure to some people. I suppose this can be treated by better software (e.g. Linux) and hardware, too.

Some people use handheld PC (e.g. PalmIII, Newton Message Pad, Psion 5) to carry around documents to read rather than printing them out.

4.4. Other Techniques

Another means of saving paper is through the use of comments and redline/strikeout markings when exchanging a document with a co-worker/colaborator. For example, a draft could be written using WordPerfect, then E-MAILed to a co-worker. They could update the draft and send it back to you. You can use WordPerfect's redline/strikeout features to see the changes. The document need not be printed until it is "final" or in "final draft" status.

Question: Can you use the back side of paper in a laser printer? I have not had much luck. You can use the paper that has been in a laser printer in an inkjet printer by using the other side.

You should purchase smaller computers and monitors when possible. This will save packaging material translating into less solid waste. For example the box for a 15" CRT monitor is 2-3 times the size of the box for a 15" LCD monitor. Linux works well with 15" LCD monitors on smaller computers like the Netwinder or E3000 .

Tough smaller monitors may have another ecological caveat: because it's inconvenient to browse to longer documents, people may tend to print the documents instead of reading them from the screen.

Some have expressed the concern that LCD displays may use more toxic materials and manufacturing processes than CRT displays, hence their usage actually may be worse on the environment. The original information above concerned the solid waste issue, which is fairly tangible and hence more controllable.

Does anyone know of studies or additional research to help clarify and resolve this issue?

Recycle your used paper, ink, and packing materials.

You may use refillable printer cartridges. In Germany the are marked with the Blauer Engel label.

Laser printer cartridges can often be used much more longer if you shake them when the message toner low appears at the message panel.

• LaTeX documents: Using \usepackage{ccfonts} replaces the usual fonts by ones with wider lines and bolder serifes, improving readability at low resolutions. They are darker (i.e. use more ink) than the CM fonts and not as beautiful, so I would not recommend them for normal-size printings.

• Size-Reduction: Instead of psnup or other parts of the pstools I recommend the psnup written in Perl4 by Malcolm Herbert (it's from 1994, and no longer maintained but however there is a descendant of it called yup, available at yup).

  It has a lot of options, which allow to set all 4 margins and the inner gutter separately. Since reduced documents are not very pretty anyway, this can be used to reduce the margin, leaving more place for the text. This probably requires some experimenting (trying new values over and over, checking the result with ghostview).

  The normally used options are:

  • -p2 (or -p4 etc., like -2 in the old psnup)

  • -NIH (don't decorate)

  • -l10 -r20 -b30 -t40 (add to margins)

  • -g50 (add to gutter)

  (these values vary depending on the papersize and the margins of the original, negative values are allowed).

• Different ink printers are more or less capable to print on the backside of already used paper sheets. Try different manufacturers. Older Canon ink printers offer 360 dpi, older HP ink printers 300 dpi. The readability of 4 pages/sheet using LaTex 10pt lies in between this features.

• Non-Linux: If you have to work with MS-Windows you should get the original Adobe-PostScript-Driver, instead of using the ones from MS-Windows. These drivers offer more than one page per paper sheet. AFAIK both psnup programs don't work with Adobe-PS, MS-Windows-PS and the PostScript extracted from MS-Windows-PDF files. The Computer-Modern-Fonts (without German diacritical characters) are available as TTF fonts on the CTAN servers. With these fonts you may enhance the aesthetical value of documents and save some paper space, too.

• Ghostscript has a new output format pswrite, which creates output in correct PostScript. This feature can be used to repair broken PostScript e.g. from Microsoft drivers, allowing their postprocessing with psnup etc.

• impose+ is a set of PostScript utilities. The main program is impose, which is used for two-up printing of DSC-compliant PostScript (including that from Netscape, dvips, and FrameMaker). It makes an effort to remove white space from the printout by probing the original PostScript for the bounding box of the printed area. This makes the output much more esthetic than does a simplistic layout of non-cropped original pages.

• hpgs is a printer driver that lets you to print on a HP 6xx Series printer using economic mode. It relies on the printer driver included in GhostScript to do everything but put the printer into economic mode.

Wade W. Hampton provided the biggest part of this chapter. Some suggestions are from Ralf Muschall.

8.1. Recycling of Hardware

The commercial computer market is largely driven by vendors seeking to sell new hardware and software. There is no commercial marketing benefit in promoting reuse.

Hence Linux doesn't require big hardware, it's very useful if you like or need to use old and small hardware.

8.2. Other Techniques

NiCad batteries need to be discharged periodically to prevent the memory effect and prolong their lifespan. Batteries such as NiCad, Lead Acid, and NiMH contain TOXIC chemicals. Techniques should be taken to prolong their lifespan, and when you do discard them, they should be recycled, not thrown in the trash. One technology to watch is the "Iron" battery mentioned in the article at N.N. . Such a battery could reduce some of the toxic waste problems associated with used batteries, however such a battery is probably a few years away. Some remarks about backlights in laptops, monitors (screensavers), harddisks (hdparm), etc. have to be written.

8.3. Linux BadRAM Patch

The objective of the BadRAM Patch is to run the Linux kernel in such a way that it can handle defective RAM modules. With defective RAM, I mean RAM which has some bits wrong at some (known) addresses. Normally, such RAM is considered useless and thrown away; the larger RAMs get, the higher the chances of failing addresses. With ever growing RAM sizes, it would therefore be pleasant to have an alternative to discarding of defective RAM chips.

8.4. Other Operating Systems

Courtesy of George White <gwhite at bodnext.bio.dfo.ca>: Or you can buy an older computer (SGI, Sun, NeXT) that comes with unix and is capable of running a wide range of open source software. In some cases (SGI Indigo2) you can still run current OS versions, in others you may do better with an open source OS such as Linux, but in either case you have access to lots of good software and tools to write your own. The lower power consumption of older computers means you get more reserve time from an UPS or can use a small alternative power source if you don't have access to "mains" power.

12.1. Ecolab

Ecolab is both the name of a software package and a research project that is looking at the dynamics of evolution. http://parallel.acsu.unsw.edu.au/rks/ecolab.html EcoLab is a system that implements an abstract ecology model. It is written as a set of Tcl/Tk commands so that the model parameters can easily be changed on the fly by means of editing a script. The model itself is written in C++.

12.2. OpenClassroom

"OpenClassroom - distribution for Education. Pre-alpha. homepage: OpenClassroom is integrating a package of software that allows educational and community organizations to create communities of knowledge by connecting their existing PCs (old or new) into a network, both local and worldwide, such as the Internet. A central focus of this initiative is to allow such organizations to extend the usable life of their equipment by bringing them state-of-the-art software that runs on their existing PCs. Our toolset allows organizations and citizens to own and operate their own digital printing press."

12.3. Tierra

Tierra is a tool for studying digital evolution and ecology that runs on Linux and other OSes.

12.4. Linux in Environmental Research

Courtesy of Wade W. Hampton: Linux is ideally suited for use as a research tool for environmental experiments. There are small embedded Linux solutions that can be used for remote monitoring or telemetry. There are VERY small Linux implementations from PC-104 systems to embedded systems like the uCsimm. Linux even flew on the shuttle controlling biological experiments.... Linux has been used for weather research on NOAA's Hurricane Hunter aircraft. Linux is also an ideal platform for researching ecological and environmental information via the Internet using standard WWW-based tools like Netscape. Linux may even be used to model complex biological and environmental processes. A ( beowulf cluster could be used to run complex simulations of environmental processes, for example Earthdome and a survey at A COLLECTION OF LINKS OF VISUALIZATION & SIMULATION OF SELF-ORGANIZED SYSTEMS.

12.5. SWARM

SWARM is a software package for multi-agent simulation of complex systems that is being developed by the Swarm Development Group (SDG).

Swarm is intended to be a useful tool for researchers in a variety of disciplines, especially artificial life. The basic architecture of Swarm is the simulation of collections of concurrently interacting agents: with this architecture, we can implement a large variety of agent based models. The source code is freely available under GNU Licensing terms.

12.6. Climate-Dynamics

Climate-Dynamics is project to share computer client resources to analyze the climate.

12.7. UNCERT

UNCERT is a geostatistical uncertainty analysis package applied to groundwater flow and contaminant transport modeling. This package was developed for evaluating the inherent uncertainty in describing subsurface geology, hydraulic properties, and the migration of hazardous contaminants in groundwater flow systems. It is well suited for the aforementioned purposes, but is also sufficiently general to be usable by researchers in a wide range of disciples.

12.8. EcoTopia

The EcoTopia web site uses computer simulation to model Santa Cruz, California as an ideal environmental community. For Ecotourists and Green Consumers, EcoTopia strives to offer the nation a model of integration of technology and environmental remediation using computer modeling and image forecasting.