OpenLLM-France/wikimedia huggingface dataset:
# GCSE Science/Generating electricity

GCSE Science/Electricity
On the last page we looked at induction. That is how the motor effect acting on electrons in wires causes them to move and create a current. On this page we will look at some practical uses of induction and how electricity is made in power stations.
Look at the diagram of an electric motor. As the coil rotates it cuts the field lines in a downwards direction then an upwards direction. This means that the electricity produced alternates. The current flows one way then the other. The frequency depends on the speed of rotation.
Q1) A motor is rotated manually to produce a current. An oscilloscope is used to investigate this current and produces a trace like the one shown. The time is on the x axis and voltage is on the y axis.
The motor is speeded up. Which one of the following shows the new trace?

## Alternating Current

In the section above you learned that a dynamo produces a.c. If you've ever looked closely at a school power pack you will probably have noticed that it has a.c. and d.c. outputs. D.c. stands for direct current. The current flows in one direction only and (apart from when it is switched on or off) doesn't change in value. A.c. constantly changes. An a.c. curve is typically that of a sine wave. The current switches back and forth and the value of the current is constantly changing.(This fact is important when we come to study transformers.)
Some devices work equally well with either a.c. or d.c. Others must have the correct type or they won't work. For example think about a child's train on a track.
If a.c. electricity is used the train will not go anywhere! This is because the current is 'telling' the motor to go forwards, go backwards, no, go forwards and so on. Anything with a small electric motor in it has to use d.c. (Special electric motors which use a.c. do exist. However, the ones you'll come across in school or in any toy application will almost certainly be d.c. motors.)
On the other hand a bulb has no problem working on a.c. This is because a bulb converts the energy of the electric current to heat and light. It makes no difference which way the current flows, the energy is still there. So bulbs, electric fires, cookers and so on do not care if they use a.c. or d.c.
Transformers (which we will study in the next section) will only work with a.c. This is because a transformer needs to have a constantly varying current, and d.c. only varies when it is switched on or off.
    Q2) Name a source of a.c. Name a source of d.c.
    Q3) Name a device that only works with d.c. Name a device which will work with a.c. or d.c.
    Q4) A hair dryer contains a heating element and a fan. Will it work best with a.c. or d.c.? Explain your answer.
    Q5) An engineer has an idea about the toy train. He thinks, "If I pass the a.c. through a certain useful electric component, I can get rid of the backward direction current and keep the forward direction current. Like this:
What useful electrical component was the engineer thinking of?---- Answers | Transformers>>
# GCSE Science/Hormones
## The menstrual cycle

The menstrual cycle is a cycle of events that occurs in the womb (uterus) and ovaries of female mammals. It is associated with the production of eggs and preparing the uterus for the implantation of fertilised eggs.
The menstrual cycle occurs over a period of about 28 days. The changes during the cycle are due to four hormones, progesterone, oestrogen, FSH (follicle stimulating hormone) and LH (luteinising hormone). Progesterone and oestrogen have wide ranging effects on the body but in the context of the menstrual cycle progesterone is mainly involved in maintaining the lining of the uterus and oestrogen is mainly concerned with building up the lining of the uterus. FSH stimulates the production of eggs and LH stimulates the release of the egg. FSH and LH are produced by the pituitary gland in the brain.
There are four stages in the menstrual cycle.
Stage 1. Days 1-4. Menstruation (bleeding) occurs. The lining of the uterus disintegrates and is shed. This is due to low levels of progesterone.
Stage 2. Days 4-14. The uterine lining grows back. This is due to high levels of oestrogen.
Stage 3. Day 14. The egg (called an ovum) is released. This is due to LH.
Stage 4. Days 14-28. The lining of the uterus is maintained in case the egg becomes fertilised and implanted in the uterus. Maintenance of the lining is due to high levels of progesterone.
The four hormones interact with each other. FSH causes Oestrogen release and oestrogen inhibits FSH. LH stimulates both oestrogen and progesterone production. Before ovulation LH release is stimulated by oestrogen but after ovulation it is inhibited by both oestrogen and progesterone.
In summary, the hormones have the following effects:
    Oestrogen: causes growth of the uterine lining. Inhibits FSH. Stimulates release of LH and hence release of the egg. Inhibits LH after ovulation.
    Progesterone: maintains the uterine lining. Inhibits LH after ovulation.
    LH: Stimulates the release of the egg (called ovulation). Stimulates oestrogen and progesterone production.
    FSH: Stimulates egg development and the release of oestrogen.
Birth control tablets contain high levels of progesterone and oestrogen. The oestrogen inhibits FSH production so that eggs cease to develop.
FSH is used to treat infertility because it stimulates the production of eggs.

### Learning the menstrual cycle

The menstrual cycle is easy to learn. The best approach is probably to break it down into parts.

## More advanced topics

This section deals with topics that are outside the GCSE syllabus.
At a more advanced level the menstrual cycle is divided into phases as shown in the diagram.
# GCSE Science/Generating electricity answers

Some thoughts on the questions posed... (perhaps this will become an 'answers' page in due course?)
Q1. Think back to the ideas presented on 'GCSE Science/Induction': Increasing the speed of rotation is like moving the magnet in and out of the coil faster, so the waveform on the oscilloscope will be bigger in relation to the y-axis (larger voltage induced). However, since the rate of rotation is increased, the frequency will also be greater, so the peaks will be closer together, hence correct answer is 'C'.
Q2. Some typical sources of a.c. are the alternator on a car and the generator at a power station. Sources of d.c. include dry cells (commonly known as 'batteries' in the UK), photovoltaic cells (solar panels), lead-acid accumulators and smoothed d.c. power supplies found in science labs.
Q3. A typical device which only works with d.c. is (as mentioned in the article - if you were paying attention!) the electric motor (the split-ring commutator type depicted in the article about the motor effect). A device which doesn't mind whether you use a.c. or d.c. is the light bulb.
Q4. Was this question put in as a red-herring, or a means of challenging brighter pupils?! Well, what did you make of it? Tricky, given the setting? Well, since hair-dryers need to blow out a lot of hot air, their power requirement is fairly large. This means that batteries won't last long enough to be a viable option! With this in mind, the only sensible thing to do is use mains, i.e. alternating current. The heater element doesn't care which way the current is flowing - it just gets hot. This does pose a problem for the motor, though. It can't be the split-ring commutator variety, since it would just vibrate on the spot, get hot, and then die! (Electric motors invariably keep their windings from overheating by drawing in cooler air from outside their housing as they rotate.) So, one of those special a.c. motors mentioned earlier has to be used...
Q5. The useful component he was thinking of is called a 'diode'.
(Most diodes are now made from semiconductor materials, but the original diode was called a 'thermionic valve'. From your knowledge of Biology (particularly of the heart) why do you think the term 'valve' is appropriate?)
# Historical Geology/Ooids and oolite

In this article we will discuss the formation of ooids, and how to recognize oolitic limestone in the geological record.

## Ooids and oolite

An ooid consists of a nucleus (a fragment of shell, a grain of sand, or whatever) around which layers of minerals are deposited to form roughly spherical grains.
These grains are typically between 0.25mm and 2mm in diameter; in fact, some authors use a different term for ooids of different sizes, but in this article we shall use the word "ooid" as a catch-all term.
Although there are a number of minerals which can form ooids, in this article we are interested in ooids formed from calcium carbonate, and from now on we shall confine our discussion to them. Such ooids are typically formed in water rich in calcium carbonate (for obvious reasons) and for preference warm shallow water agitated by waves.
Today ooids are to be found in a number of locations with warm shallow water, including the Bahamas, Shark Bay in Australia, and the Persian Gulf, all of which are marine sites; but they are also sometimes found in inland waters such as the Great Salt Lake in Utah.
Like other small grains, ooids can be cemented together to form a kind of rock. Rock formed from Calcium carbonate ooids is, by definition, a form of limestone, and is known as oolitic limestone or oolite. The term oolith may also be used as a term either for the rock or for an individual ooid.

## Oolite: how do we know?

It is very easy to distinguish limestone formed from ooids. Magnified, it looks like it is made of ooids, as shown in the top picture to the right. (The limestone in this photograph and the one below is from the Carmel Formation in southern Utah.)
This resemblance might be fortuitous, but any such conjecture is laid to rest by looking through a microscope at a cross-section of oolite, as shown in the lower picture to the right.
Not only are the grains the right size and shape to be oolites, but in cross-section one can see the nuclei around which they formed and the growth patterns typical of oolites. Plainly, then, what we are looking at is ooids cemented together to form oolite.
← Reefs · Calcareous ooze →
# History of video games/Platforms/Arcadia 2001
## History

Phillips created an example platform for one of their chipsets, leading to a number of small mostly compatible consoles based on their specifications, one of the most popular being the Emerson Arcadia 2001. Other notable compatible systems included the German Tele-Fever and the officially licensed Canadian console Leisure Vision.
Emerson Radio cooperation released the Emerson Arcadia 2001 in 1982.
Thousands of game cartridges for the Arcadia 2001 were barred from sale due to legal issues.

## Technology
### Compute

The console is powered by a Signetics 2650A CPU clocked at 3.58 MHz.
The system has 1 kilobyte of RAM. Some materials suggested the Emerson Arcadia 2001 had 28 or 24 kilobytes of RAM, which was not true.

## Gallery
### Console

* The Arcadia 2001 with controllers docked.
* The Arcadia 2001 without controllers.
* The bottom of the unit containing serial number, regulatory information, and a quality control sticker.
* Rear of the unit with channel switch, and DC power input.

### Controller

* Each controller is labeled along the bottom. This is the left hand controller.
* The joystick could be unscrewed, as seen here.
* Phillips head screws hold the controller together.

### Teardown

* Left and right controllers technically use plugs, but on the inside of the console.
* Significant RF shielding lines the bottom of the Arcadia 2001.
* The internals propped open, revealing more RF shielding, as well as cables leading to the front buttons.
* Bottom of the case.
* The top of the Motherboard. Note the lack of PCB traces on the top of the board.
* The bottom of the Motherboard contains a number of hand soldered jumper wires.
* RF Shielding separates the outside world, the motherboard, and the power supply.
* A large ferrite ring is used on the power supply cable, which helps noise suppression.
* The bottom of the motherboard. A mark can be seen in the upper left.
* The bottom of the motherboard.
* Die of the Signetics 2650A, the model of CPU used in the Arcadia 2001.
* A 1975 advertisement for the Signetics 2650 processor, advertising its ease of use. Note that ease of use referred to implementing the hardware, with less attention paid to software.

## References

* 1 2 3 "OLD-COMPUTERS.COM : The Museum". www.old-computers.com. Retrieved 23 October 2020.
* 1 2 "TOSEC: Emerson Arcadia 2001 (2012-04-23)". 23 April 2012. Retrieved 23 October 2020.
* ↑ "Arcadia 2001 -- FAQ guide". www.digitpress.com. Retrieved 29 October 2020.
* ↑ "History of Consoles: Arcadia 2001 (1982) Gamester 81". Retrieved 29 October 2020.
* ↑ "Home Page". Video Game Console Library. Retrieved 29 October 2020.
# History of video games/Platforms/Anbernic RG ARC
## Technology

The system was sold in both two versions, a high end "D" model, and a lower end "S" model. Both systems were based on the quad core RK3566, clocked at 1.8 GHz.

### Hardware

The design of the system is commonly cited as being inspired by the Sega Saturn.

## References

* 1 2 Wong, Raymond (8 November 2023). "This Sega Saturn-Inspired Handheld Can Play Dreamcast Games" (in en). Inverse. https://www.inverse.com/tech/anbernic-rg-arc-emulator-handheld-dreamcast.
* 1 2 Wallace, Anthony (24 October 2023). "ANBERNIC Reveals NEW RG-ARC, A SEGA Inspired Retro Handheld". Retro Dodo. https://retrododo.com/anbernic-reveals-new-rg-arc-a-sega-inspired-retro-handheld/.
* ↑ Alderson, Alex (7 November 2023). "Anbernic RG ARC: Sega Saturn-inspired gaming handheld to launch later this week from US$69.99" (in en). Notebookcheck. https://www.notebookcheck.net/Anbernic-RG-ARC-Sega-Saturn-inspired-gaming-handheld-to-launch-later-this-week-from-US-69-99.765950.0.html.
# History of video games/Platforms/Apple Watch
## History
### Launch

In 2014 the Apple Watch was announced, launching later in 2015.

### Role in gaming history

While gaming was never a focus for the device, some tenacious game developers sought to make their mark on the platform, with some early developers anticipating a boom in the smartwatch gaming market similar to the smartphone gaming market.
Some game developers saw a different utility for the Apple Watch, instead using it as a second display for mobile phone games with companion apps.

## Notable Games
### 2015
#### Watch Quest!

Watch Quest was an entry related to the Shantae Series developed exclusively for the Apple Watch.

### 2016
#### Cosmos Rings

Cosmos Rings was a minimalist role playing game made by Square Enix exclusively for the Apple Watch.

### 2019
#### Pocket Bandit

Safe cracking game, making use of the watch crown as a control method.

## References

* ↑ "Apple Watch: The net reacts to Apple's first wearable". BBC News. 9 September 2014. https://www.bbc.com/news/technology-29136063.
* ↑ "Apple Watch prices and apps revealed". BBC News. 9 March 2015. https://www.bbc.com/news/technology-31794823.
* ↑ "It’s not easy to make Apple Watch games, but developers are doing it anyway". VentureBeat. 24 April 2015. https://venturebeat.com/2015/04/24/its-not-easy-to-make-apple-watch-games-but-developers-are-doing-it-anyway/.
* ↑ Webster, Andrew (10 April 2015). "One of the first Apple Watch games is an RPG for your wrist" (in en). The Verge. https://www.theverge.com/2015/4/10/8376769/apple-watch-game-runeblade.
* ↑ Kahn, Jordan (22 April 2015). "A look at gaming on Apple Watch: 2048, Modern Combat 5, Real Racing, FIFA, & many more (Screenshots)". 9to5Mac. https://9to5mac.com/2015/04/22/gaming-apple-watch-2048-modern-combat-5-real-racing-fifa-screenshots/.
* ↑ "Apple Watch is getting an adventure game from Shantae developer WayForward". VentureBeat. 14 April 2015. https://venturebeat.com/2015/04/14/apple-watch-is-getting-an-adventure-game-from-shantae-developer-wayforward/.
* ↑ "Watch Quest!". WayForward. Retrieved 18 September 2021.
* ↑ "Square Enix's first Apple Watch RPG is stylish yet dull". Engadget. https://www.engadget.com/2016-07-29-apple-watch-rpg-cosmos-rings.html.
* ↑ "Pocket Bandit game lets you use your Apple Watch to crack safes". Geeky Gadgets. 4 June 2019. https://www.geeky-gadgets.com/pocket-bandi-04-06-2019/.
* ↑ "The game that turns your Apple Watch into a safe you can crack is a hidden gem" (in en-gb). Eurogamer.net. 4 June 2019. https://www.eurogamer.net/the-game-that-turns-your-apple-watch-into-a-safe-you-can-crack-is-a-hidden-gem.
# History of video games/Platforms/Apple II
## History

The Apple II was launched in April 1977.
The Apple II was discontinued in 1993, having been a critical platform in the Computer market, and by extension the computer gaming market, for well over a decade and a half.
Around 2017 a massive effort was made to preserve as much Apple II software as possible, before media degradation made some software lost to history.

## Technology

These specs are for the original Apple II. Later models offered enhanced capabilities.

### Compute

The Apple II is powered by an 6502 processor clocked at 1 megahertz.
The Apple II originally shipped with 4 kilobytes of RAM, and could be expanded to 48 kilobytes.

### Hardware

The Apple II shipped with an 8 kilobyte ROM.

## Gallery

* The old garage of Steve Jobs in Los Altos, California.
* An Apple II running a game.
* Mystery House running on an Apple II.
* An 1977 advertisement for the Apple II encourages not only playing games with the system, but also creating them.
* The Apple II owned by John Romero.

## References

* ↑ "Apple II Personal Computer". National Museum of American History. Retrieved 28 November 2020.
* ↑ Contributor, Minda Zetlin (23 January 2020). "These old Apple computers are worth up to $905,000—and you might have one sitting in your basement". CNBC. Retrieved 28 November 2020. {{cite web}}: |last1= has generic name (help)
* ↑ "Programmers Are Racing to Save Apple II Software Before It Goes Extinct" (in en). www.vice.com. https://www.vice.com/en/article/gv39mx/programmers-are-racing-to-save-apple-ii-software-before-it-goes-extinct.
* ↑ "Today in Apple history: The final Apple II model arrives". Cult of Mac. 15 September 2018. Retrieved 28 November 2020.
* 1 2 3 "Apple II advertisement". Retrieved 28 November 2020.
# History of video games/Platforms/Apple TV
## History

The Apple TV is a series of multimedia boxes, which heavily featured gaming.

## References

* ↑ Nast, Condé. "Is Apple TV gearing up to be a full-fat games console?". Wired UK. https://www.wired.co.uk/article/apple-tv-arcade-gaming.
* ↑ "Planning on Gaming on the New Apple TV? You’ll Need a Game Controller". iDrop News. 23 April 2021. https://www.idropnews.com/news/planning-on-gaming-on-the-new-apple-tv-youll-need-a-game-controller/157049/.
# History of video games/Platforms/Anbernic RG351
## History

The Anbernic RG351 series are a line of emulation oriented handheld game consoles.
The handheld was announced in September 2020.

## Technology
### Compute

The system uses a Rockchip RK3326 quad core CPU clocked at 1.5 Gigahertz. The system has 1 gigabyte of DDR3L RAM.

### Software

The RG351 series ran Linux as an Operating System.

### Models

* RG351P - Plastic Version.
** White casing
** Black casing
** GBA Blue casing
* RG351M - Metal Version with Wifi built in.
* RG351V - Vertical Orientation.

## References

* 1 2 3 4 5 "GBAtemp Exclusive - Anbernic officially releases RG351 details and announces launch of its official YouTube channel". GBAtemp.net - The Independent Video Game Community. https://gbatemp.net/threads/anbernic-officially-releases-rg351-details-and-announces-launch-of-its-official-youtube-channel.573795/.
* 1 2 3 "Anbernic RG351P Review" (in en). PCMAG. https://www.pcmag.com/reviews/anbernic-rg351p.
* 1 2 "Hands On: Retro Handheld Face-Off - Anbernic R351 Vs Retroid Pocket 2". Nintendo Life. 2 July 2021. https://www.nintendolife.com/news/2021/07/hands_on_retro_handheld_face-off_-_anbernic_r351_vs_retroid_pocket_2.
* ↑ "Hands On: The Anbernic R351V Offers A Real 'Game Boy' Vibe". Nintendo Life. 28 August 2021. https://www.nintendolife.com/news/2021/08/hands_on_the_anbernic_r351v_offers_a_real_game_boy_vibe.
# History of video games/Platforms/Asterisk
## History

The device cost $20.

## Technology

A CR2032 coin cell battery powers the console.

## References

* ↑ Yarwood, Jack (25 July 2022). "Random: Creator Makes Adorable Tiny Tetris-Like Device". Time Extension. https://www.timeextension.com/news/2022/07/random-creator-makes-adorable-tiny-tetris-like-device.
* ↑ Liszewski, Andrew (22 July 2022). "Tiny Handheld Boils Tetris Down to Its Bare Essentials" (in en-us). Gizmodo. https://gizmodo.com/tiny-tetris-handheld-tindie-store-asterisk-pcb-retro-1849320704.
# GNU Data Language/BYTEORDER

BYTEORDER,[inf. Args],SSWAP,LSWAP,L64SWAP,SWAP_IF_BIG_ENDIAN,SWAP_IF_LITTLE_ENDIAN,NTOHL,NTOHS,HTONL,HTONS,FTOXDR,DTOXDR,XDRTOF,XDRTOD

##### PARAMETERS

* [inf. Args]
* SSWAP
* LSWAP
* L64SWAP
* SWAP_IF_BIG_ENDIAN
* SWAP_IF_LITTLE_ENDIAN
* NTOHL
* NTOHS
* HTONL
* HTONS
* FTOXDR
* DTOXDR
* XDRTOF
* XDRTOD
# GNU Data Language/CALL METHOD

CALL_METHOD,[inf. Args],_REF_EXTRA

##### PARAMETERS

* [inf. Args]
* _REF_EXTRA
# GNU Data Language/CD

CD,[1 Arg],CURRENT

##### PARAMETERS

* 1
* CURRENT
# GNU C Compiler Internals/Style Hacks 4 1

These exercises are from http://gcc.gnu.org/projects/beginner.html

## Break up enormous source files

Not terribly hard. Watch out for file-scope globals. Suggested targets:
Big Files :
| File Size | File Name |
| 494K | java/parse.y |
| 413K | combine.c |
| 408K | dwarf2out.c |
| 375K | cp/pt.c |
| 367K | fold-const.c |
| 356K | loop.c |
There are several other files in this size range, which I have left out because touching them at all is unwise (reload, the Fortran front end). You can try, but I am not responsible for any damage to your sanity which may result.

## Break up enormous functions

This is in the same vein as the above, but significantly harder, because you must take care not to change any semantics. The general idea is to extract independent chunks of code to their own functions. Any inner block that has a half dozen local variable declarations at its head is a good candidate. However, watch out for places where those local variables communicate information between iterations of the outer loop!
With even greater caution, you may be able to find places where entire blocks of code are duplicated between large functions (probably with slight differences) and factor them out.

## Break up enormous conditionals

Harder still, because it's unlikely that you can tell what the conditional tests, and even less likely that you can tell if that's what it's supposed to test. It is definitely worth the effort if you can hack it, though. An example of the sort of thing we want changed:

## Delete garbage

#if 0 blocks that have been there for years, unused functions, unused entire files, dead configurations, dead Makefile logic, dead RTL and tree forms, and on and on and on. Depending on what it is, it may not be obvious if it's garbage or not. Go for the easy ones first.

## Use predicates for RTL objects

GCC has simple predicates to see if a given rtx is of some specific class. These predicates simply look at the rtx_code of the given RTL object and return nonzero if the predicate is true. For example, if an rtx represents a register, then REG_P (rtx) is nonzero.
Unfortunately, lots of code in the middle end and in the back ends does not use these predicates and instead compare the rtx_code in place: (GET_CODE (rtx) == REG). Find all the places where such comparisons can be replaced with a predicate. Also, for many common comparisons there is no predicate yet. See which ones are worth having a predicate for, and add them. You can find a number of suggestions in the mailing list archives.
# GNU Data Language/CATCH

CATCH,[1 Arg],CANCEL

##### PARAMETERS

* 1
* CANCEL