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Talk:Retribution (StarCraft)

Inclusion in Blizzard Entertainment footer
I really don't think this belongs in the footer box at the bottom of other Blizzard game articles - it's not even found on Blizzard's page. It's a third party lacklustre expansion, not unlike D!Zone and the like for Doom. I am going to cut it from those things along with Insurrection unless someone has a good reason they should stay. Deusfaux 23:31, 30 May 2006 (UTC)

 * Regardless of whether they are part of the Blizzard footer, they are officially part of the StarCraft universe - as said in the Insurrection discussion page, they are given official recognition in the Battlenet FAQ. I've added this and Insurrection into a new "Games" part of the StarCraft universe footer, which (naturally) includes StarCraft, Brood War and Ghost. S@bre 17:37, 16 May 2007 (UTC)

 * That means they are endorsed by Blizzard but still neither Retribution or Insurrection has been developed by Blizzard and thus has no place in the Blizzard footer. It can be included in the StarCraft footer. Also, even if Blizzard made these add-ons, the footer only lists the main games, no expansions or add-ons. --Fogeltje 21:15, 16 May 2007 (UTC)

Links/sources
There any links or sources for this? I'm a pretty big Starcraft fan, and this is the first I've heard of this. Kuralyov 23:41, 20 Apr 2005 (UTC)

 * I don't think they can be bought anymore (perhaps not even eBay). You should be able to find them on the ed2k network. Tzarius 03:23, 11 May 2005 (UTC)

 * Please do not suggest such things here. Please remember that this is still copyrighted material.  Thank you. --- Randilyn 10:49, 29 December 2006 (UTC)

Blizzard?
so did blizzard make starcraft: retribution? —Preceding unsigned comment added by Tzarious (talk • contribs) 23:23, May 10, 2005 (UTC)

 * No. The article says so. Blizzard only authorized it. Please sign entries with four Tildes (~). Zirka 07:29, 3 April 2006 (UTC)

Sys Req's
Has anyone been able to find any paperwork on this? I'm higly speculative that the game requires a Pentium III to run, even though a minimum of 16 MB of RAM and 50 MB of HDD space will do the trick. Further doubt is cast when the article mentions that the game engine isn't changed, and the expansion only adds campaign and multi-player maps. I plan to edit the article to reflect that. Zirka 07:29, 3 April 2006 (UTC)

 * The system requirements are exactly the same as the original StarCraft, except that 50 megs of additional disk space is required. This can probably be actively seen on the high resolution box shots over at MobyGames, although I haven't taken the time to check them myself. --- Randilyn 10:49, 29 December 2006 (UTC)

 * The system requirements box was ridiculously large. I've cut it down a bit S@bre 17:39, 16 May 2007 (UTC)

 * The above statement (sys reqs same as Starcraft) probably means the game can also be run on a Mac. Scott —Preceding unsigned comment added by 71.207.151.85 (talk) 01:46, 21 January 2008 (UTC)

StarCraft: Retribution
The name of the expansion pack is Retribution, not StarCraft: Retribution. StarCraft: Retribution is only an informal name used by review sites, etc. when talking about the game. Nowhere is it ever stated that the game uses Blizzard's StarCraft trademark in the name, except for the presense of the logo on the box shot, in which case it doesn't even appear before Retribution in the title, but rather afterwards, and as more of an addendum to the title. Retribution (StarCraft) is probably more correct. --- Randilyn 10:55, 29 December 2006 (UTC)

 * Furthermore, it would seem that the (formally) accepted full title for the game is Retribution: Authorized Add-On for StarCraft, which matches the box art exactly. I've fixed the article to reflect this, but only in one occurence, as any more would be superfluous. --- Randilyn 12:59, 29 December 2006 (UTC)

Release date
All evidence (including the MobyGames page) seems to point to this actually being released in 1998, not 2001. This makes since primarily because it does not use any of the Brood War content, which was either still under development at the time, or had just hit the shelves. Further evidence is provided by the fact that the game was developed by Stardock back when they were still known as Stardock Systems, which was long before they became known as just Stardock (considering that there were other name change(s), such as Stardock.net, during that time). I'm changing the release date until someone presents evidence that the game was in fact released in 2001. --- Randilyn 12:10, 29 December 2006 (UTC)

Improved AI?
I am a seasoned StarCraft modder (modification builder) for many years and I know for a fact that you cannot improve the StarCraft AI beyond the basic trigger abilities of StarEdit without a game data (MPQ) patch. I also noticed on certain game review sites that people complained of missing music and cinematics. These also require game data patches. Is it possible that they were accidentally just playing the missions from the game using the Single Player Custom Game feature, and the CD actually came with a game data patch, or is this all hogwash? If it is, then the improved AI claim needs to be removed, or, at the very least, cited. --- Randilyn 12:29, 29 December 2006 (UTC)

New Stuff
Are there any new units? —Preceding unsigned comment added by 199.247.235.10 (talk • contribs) February 26, 2007
 * No. --M.A. 10:15, 20 May 2007 (UTC)

Citation needed?
"Argus crystals are used by Dark Templar as a powerup[citation needed]." Can't someone simply play the game and see if that's true? —Preceding unsigned comment added by 87.203.73.129 (talk • contribs) March 6, 2007

 * I've finally managed to aquire the game, so I can do that. However, its a bit difficult to cite that fact from anotherpage -- S@bre 17:40, 16 May 2007 (UTC)

 * Argus talisman and Argus jewel upgrades listed, if you need sources :) Better point to Brood War's page than those directly, though. --M.A. 10:14, 20 May 2007 (UTC)

 * Done. Never noticed that it was part of Brood War. I'll expand the rest of the plot section later. -- S@bre 12:02 21 May 2007 (UTC)

Fair use rationale for Image:RetributionBox.jpg
Image:RetributionBox.jpg is being used on this article. I notice the image page specifies that the image is being used under fair use but there is no explanation or rationale as to why its use in this Wikipedia article constitutes fair use. In addition to the boilerplate fair use template, you must also write out on the image description page a specific explanation or rationale for why using this image in each article is consistent with fair use.

Please go to the image description page and edit it to include a fair use rationale. Using one of the templates at Fair use rationale guideline is an easy way to insure that your image is in compliance with Wikipedia policy, but remember that you must complete the template. Do not simply insert a blank template on an image page.

If there is other fair use media, consider checking that you have specified the fair use rationale on the other images used on this page. Note that any fair use images uploaded after 4 May, 2006, and lacking such an explanation will be deleted one week after they have been uploaded, as described on criteria for speedy deletion. If you have any questions please ask them at the Media copyright questions page. Thank you.

BetacommandBot 19:59, 24 October 2007 (UTC)

Merge of article
As per: RfC

 * Re: The merge of Insurrection (StarCraft) and Retribution (StarCraft) to Starcraft. My biggest concern is a significant amount of information was deleted in this merge.

 * Reason for merge of Insurrection (StarCraft)

Reason 1:

 * "...due to how little reception the game has got, it is highly difficult to find sources for most of it. The only source I could find was that Gamespot review, copied over and over onto other websites - as I said, other established reviewers don't seem to have reviewed it."

Reason 2:

 * "Aztech New Media's site and company no longer exist, so there is no help there either."

 * Reason for merge of Retribution (StarCraft)
 * "Merging as full notability for a separate article cannot be established"

Since WizardWorks website does exist (redirected to Atari), unlike Aztech New Media, does this help the notability?

 * Retribution references
 * 1) Computer Games Magazine
 * 2) The Advocate - NewsBank - Jan 22, 1999: "GT Interactive Software pays homage to StarCraft with its new add-on disc, Retribution. In its story, the argus stone, an ancient artifact of great power..."
 * 3) mobygames.com

 * Insurrection references
 * 1) Gamespot review, already on the Insurrection page.
 * 2) Absolute Games (AG.ru),
 * 3) Computer Gaming World Magazine (CGW),
 * 4) PC Player magazine (Germany)  and
 * 5) mobygames.com all which have wikipedia sites., includes all credits.
 * 6) Business Wire November 4, 1998, Aztech New Media Signs Contract With Microsoft Corp. for Urban Assault Enhancement Package - November 4, 1998 "Aztech's Insurrection(TM), Campaigns for StarCraft(TM), based on Blizzard Entertainment's bestselling game, has sold 75,000 copies across North America since June 1, 1998."
 * 7) Avault review by Pete Hines June 28, 1998

 * Retribution and Insurrection references

Blizzard Frequently ask questions:

 * Insurrection is an add-on pack with new single-player campaigns and additional maps for single and multiplayer play. It is currently available from Aztech New Media.

 * Retribution is an add-on pack by WizardWorks, creators of W!Zone and other add-on packs. It will include entirely new single-player campaigns and an assortment of new maps.

 * Merge tag

There was no tag added to Retribution (StarCraft) before the merge.

There was a merge tag added to Insurrection (StarCraft), the comments on Talk:StarCraft_(series) were, other than the nominator, one to keep, and one to merge. The merge happened on 21:29, 26 August 2008.

travb (talk) 22:31, 4 January 2009 (UTC)

 * Notability is not inherited from the company that produced the product. If you want to restore these articles, please present solid sources that would allow for concrete reception and development sections to be built. A merge discussion was open for thirteen days on the location specified on the merge tag, WP:VG was informed of the discussion and no opposition was voiced. These articles were were merged as sources do not exist—believe me, I wanted to properly write these articles, I spent long enough looking but this is the extent of it: . Only one reliable source, a GameSpot review, is available for Insurrection, whilst Retribution has no real reliable sources giving significant coverage, thus they are covered in the StarCraft and StarCraft series articles. Reverting these merges without any sources and on mere technicalities is entirely counter-productive to the StarCraft coverage on Wikipedia, as they simply cannot be improved in-line with WP:N or WP:V. As for the alleged loss of information, WP:V kicks in here, the information cannot be confirmed in reliable secondary sources, so it is covered as sufficiently as sources allow in other articles. -- Sabre (talk) 22:32, 4 January 2009 (UTC)
 * Thanks for your comments, I will try to address them all. travb (talk) 22:34, 4 January 2009 (UTC)
 * I've alerted WP:VG to this discussion, for further outside opinion. -- Sabre (talk) 22:42, 4 January 2009 (UTC)
 * is a fleeting mention, it is not even vaguely useful as either reception of development information. The article there focuses on the series in relation to StarCraft and StarCraft II, not Insurrection or Retribution. Significant coverage is vital, you can't write a good article on a mere couple of words like this. -- Sabre (talk) 22:47, 4 January 2009 (UTC)
 * Please understand, I am not writing this to convince you, as your opinion seems already made up, I am writing this for others. travb (talk) 22:58, 4 January 2009 (UTC)
 * Doesn't stop him from commenting on your attempts to provide sources. Everything you've turned up so far is incredibly trivial coverage. This is a fleeting mention, as is this, a Google News search turns up zilch, and the Wikia article is entirely in-universe. There's nothing here to create a GA from these articles. You go as far as your sources can take you, and in this case, there's nothing to write a substantial article on. Merge both. — sephiroth bcr  ( converse ) 23:04, 4 January 2009 (UTC)
 * Your right, it doesn't stop the merger from commenting.
 * Maybe you missed:
 * Absolute Games (AG.ru),
 * Computer Gaming World Magazine (CGW),
 * PC Player magazine (Germany) and
 * mobygames.com all which have wikipedia sites.
 * This meets and exceeds notability guidelines. travb (talk) 23:12, 4 January 2009 (UTC)
 * These aren't sources. The only ones with significant coverage are userbuilt sites, inherently unreliable. The rest are fleeting mentions or supposed articles you can't actually show - how can one create a proper article from vague references, unreliable sources and articles that cannot be easily accessed to determine if they are even significant coverage? This discussion is rapidly turning futile. -- Sabre (talk) 23:18, 4 January 2009 (UTC)
 * Having a page on Wikipedia is not the same as being a reliable source. Case in point VGChartz which is notable for its unreliability.  The VG project avoids mobygames in the same way we avoid IMDB for reliable information since there's not quality control of the user-submitted information.  --M ASEM  23:22, 4 January 2009 (UTC)
 * (edit conflict) MobyGames isn't reliable. The fact that a website has a page on Wikipedia does not equate with it being a reliable source for usage in articles. And tone down the condescending rhetoric. That you're insulting Sabre for not trying hard enough here after all the work he's done on the StarCraft articles here is utterly pathetic. The rest of your stuff is all incredibly minor mentions of both. Notability isn't really the question you should be searching for. It's whether you can actually make a substantial article on the subject with your sources, and you can't with what you have here. Given that you likely have no idea what actually constitutes a GA-quality article on the subject, I'm not surprised at this point. — sephiroth bcr  ( converse ) 23:23, 4 January 2009 (UTC)
 * These references are notable enough to have their own wikipedia pages on them. All four magazines and sites have significant articles on Wikipedia.
 * This is a common tactic: Focus on the weakest source (mobygames) and blatantly ignore the rest. There is no argument here about Computer Gaming World Magazine and PC Player magazine. Both magazines are not notable? Please don't disregard notability (sources) simply because it is now inconvenient to your argument, this was the central reason that the pages were redicted. Now that notability is no longer an issue,  editors are now creating other reasons why these articles should be merged.  A full article in Computer Gaming World Magazine and PC Player magazine is not "substantial" enough? Please. Notability guidelines state an article should have multiple reliable sources. As the only editor who is contributing substantial material in the form of references to this article I have exceeded this bar. travb (talk) 23:32, 4 January 2009 (UTC)
 * Please leave your inclusionist rubbish behind, extremist views of either side are entirely unhelpful. As already pointed out, we have absolutely no clue to how substantive those magazine articles are, we can't look at them and actually see if anything in them is usable. The mere fact they might exist is not helpful for dealing with this subject's coverage. You're arguing technicalities versus reality here: you can't write an article based on something you can't see and a bunch of sources that don't say anything beyond acknowledging their existance. And coverage of a work on Wikipedia does not, as already stated, make it a reliable source. -- Sabre (talk) 23:43, 4 January 2009 (UTC)
 * (ec) Again, there are sources out there that have Wikipedia pages but you would never use them as a reliable source (VGChartz is known for questionable sales data, and 4chan would be the last place I'd go for a reliable source. That's the distinction we are trying to make with some of the sites you've listed, in particular Mobygames which is based on solely user contributions and no editoral insight as needed by WP:RS.
 * Now, we're not saying CGW and the PC Player magazines are not notable in of themselves, nor are they unreliable. Unfortunately, it is impossible to judge what those articles are from both sources, but based on the segment provided at Mobygames, it looks like a review.  Ok, fine, there are at least 3 reviews of the game.  However, VG articles that cannot be expanded with development information and without more significant reviews are generally merged of the necessary information (including those critical reviews) into an appropriate parent article, as generally happens with mods, third-party expansions, and the like.  Or to put it this way: while the notability bar is barely passed and thus there could be separate articles for these, a better quality article is obtained by merging these into the Starcraft series article where we don't have to repeat the gameplay and fundamental basis of the in-universe aspects of the game, and yet still provide the needed coverage of the game.  Not every notable topic needs its own article. --M ASEM  23:49, 4 January 2009 (UTC)

Lets be honest, no matter how many sources I provide, it will never change the opinions here. The editor above states that the notability bar is passed, then voices his own opinion, another hurdle to jump, which is not supported by wikipedia guidelines.

Here is a challenge: I provide the full Computer Gaming World Magazine article and the editors here agree to the merge. But then again, I know the answer to this. travb (talk) 00:01, 5 January 2009 (UTC)

 * The only policy here in play is that for an article on a topic to exist, there needs to be secondary sources per WP:N. That seems to be shown (CGW and PC Player mag reviews, but as we can't tell if that's the only line about them or a small section, it's impossible to judge).  However, there is no requirement that a topic shown to be notable to need its own article - sometimes a better quality article can be obtained by merging notable topics into the body of a larger one.  This appears to be what Sabre's trying to do, so all that could basically be said about these games would leave this article very stubby with no potential for growth in light of the current sources (and given their age, we shouldn't be expecting new sources to be appear).  It is not meant to say neither game is not notable, only that covering the games as part of the series article makes their coverage much better as part of an article that can likely be featured, instead of two stubs floating around indefinitely. --M ASEM  00:16, 5 January 2009 (UTC)
 * I personally would support a stubby article, over a merged one. As this discussion seems to have evolved into a Manual of Style discussion.
 * I want to apologize to everyone here about how I have acted, especially S@bre, who I apologized on his talk page. travb (talk) 00:23, 5 January 2009 (UTC)
 * Well, again, I'm presuming that the two aforementioned reviews are substantial to state that the games are notable - that needs to be merited. The thing to remember here is that 1) it's a merge, no information has been lost, as that leads to 2) if new information that does make a better article appears, we can pull from the history to create the better article.  In the meantime, while stubs are great for a start of an article, the case here is that Sabre and others have worked to try to expand this without success, so it's likely bound to stay stubby forever, which is not appropriate for a WP article - all WP articles should be written with the aim to be as good as any other featured article (save that we've no timeline to reach that).  By good faith, even with your sources presented, I cannot see this article getting much better than a stub, and thus we should consider how to cover it better.  The merge is the best way to do that in case we change our minds n the future, and we don't lose coverage of either topic since the redirection is still searchable and the sources presented can be described in the series article. --M ASEM  00:43, 5 January 2009 (UTC)
 * Excellent points! :) Your first point it the reason why I have decided to abandon this for now. Best wishes. travb (talk) 00:58, 5 January 2009 (UTC)

title: Talk:Retribution (StarCraft)


text: User talk:199.217.208.172

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: User talk:199.217.208.172


text:
Wikipedia:Articles for deletion/Eamonn Geraghty

 This page is an archive of the discussion about the proposed deletion of the article below. This page is no longer live. Further comments should be made on the article's talk page rather than here so that this page is preserved as an historic record. The result of the debate was delete. — Xezbeth 05:51, Apr 29, 2005 (UTC)

Eamonn Geraghty
Biographical, but subject does not appear to be significant in any particular way. Musser 23:45, 20 Apr 2005 (UTC)
 * Delete. Practically nonsensical, and completely insignificant. – Seancdaug 23:55, Apr 20, 2005 (UTC)

 * Delete, personal attack. Megan1967 05:05, 21 Apr 2005 (UTC)
 * Delete. And... I'm supposed to care? Mo0 [ talk ] 06:16, 21 Apr 2005 (UTC)

 * This page is now preserved as an archive of the debate and, like some other VfD subpages, is no longer 'live'. Subsequent comments on the issue, the deletion, or the decision-making process should be placed on the relevant 'live' pages. Please do not edit this page.


text:
Signetics 2650

The Signetics 2650 was an 8-bit microprocessor introduced in July 1975. According to Adam Osborne's book An Introduction to Microprocessors Vol 2: Some Real Products, it was "the most minicomputer-like" of the microprocessors available at the time. A combination of missing features and odd memory access limited its appeal, and the system saw little use in the market.

Development

In 1972, Signetics' Jack Curtis hired John Kessler of IBM to lead the design of a new single-chip CPU intended to compete with minicomputer systems. Kessler selected the IBM 1130 as the model for the new design. The 1130, released in 1965, was a 16-bit minicomputer that shared many design features with other minis of the era.

While Kessler designed the architecture, Kent Andreas laid out the CPU using a recently developed ion implantation NMOS process. In contrast to the far more common PMOS process of the era, NMOS used less power and dissipated less heat. This allowed the chip to be run at higher speeds than PMOS CPU designs, and the first 2650's ran at the same 1.25 MHz speed as the contemporary models of the 1130.

When it was designed in 1972, the 2650 was among the most advanced designs on the market, easily outperforming and out-featuring the Intel 4004 and 8008 of the same era. In spite of this, the design was not released to production. At the time, Signetics was heavily involved with Dolby Laboratories, developing integrated circuits that implemented Dolby's suite of noise-reduction systems. Production of the 2650 was pushed back, and the CPU was not formally introduced until July 1975. By 1975, several new CPUs had been introduced, designed from the start to be 8-bit machines rather than mimicking an older design, and the 2650's advantages were no longer as compelling.

In 1975, Philips purchased Signetics, and from that point versions of the 2650 can be found with both Signetics or Philips branding.

In March 1976, Signetics reached a second-source agreement with Advanced Memory Systems (AMS). At that time, most CPU firms were very small and no one would buy a design from a company that might go bankrupt. Second-sourcing was an important guarantee that the design would remain available in this eventuality. AMS was already acting as a second-source for the RCA 1802, an advanced CMOS design, and the NMOS 2650 was seen as a useful adjunct that would not directly compete with the 1802. Unfortunately, in November AMS was purchased by Intersil, who had their own Intersil 6100, a single-chip version of the PDP-8 mini. Intersil dropped production of the 2650.

Signetics tried again with National Semiconductor in 1977, who planned to introduce versions in the last quarter of the year. For unknown reasons, this appears to have never happened, and only a single example of an NS version, from France, has ever been found.

Signetics continued the development of the 2650, introducing two new models in 1977. The 2650A was a reworked version of the original layout intended to improve yield, and thus reduce cost. Speed remained unchanged at 1.25 MHz for the base model and 2 MHz for the -1 versions. The 2650B was based on the A, added two new instructions, and improved the performance of a number of existing instructions.

Description

The overall design of the 2650 was based on the IBM 1130. As such, the 2650 has a number of features that were common on 1960s minicomputers, but rarely found on newly designed microprocessors of the 1970s. Among these, for instance, were status bits that were used to track the status of input/output devices, which makes it simpler to write interfacing code. Another mini-like feature was its use of vectored interrupts, which allowed devices to call the correct interrupt handler code by putting its memory location on the data bus and then forcing an interrupt. This avoids the need to write a centralized interrupt handler that reads additional data from the bus, determines which device driver is being invoked and then calls it; the 2650 can jump directly to the correct code, potentially stored on the device itself.

The 2650's processor registers were divided into sets, with a single global register R0 used as the accumulator, and two sets of three index registers, both named R1, R2 and R3, for a total of seven registers. At any one time, one of the two sets of indexes were visible to the CPU. Which set was visible was controlled by a bit in the status register, PSW. One could easily switch between the two sets of registers with a single instruction. This allowed rapid switching of values during subroutine calls, operating system switches, or handling interrupts. Unlike the 1130, the registers were only 8-bit wide rather than 16-bit, but there were two sets in the 2650 rather than one in the 1130.

Another of its mini-like features was the extensive support for indirect addressing on most instructions. Many instructions require data to be read from a location in memory, in most CPUs of the era that would be a single byte of data that is stored in memory referred to by a 16-bit location. In the 2650, the high-bit of that 16-bit location indicated indirection, meaning that the data was not located at this location in memory, but the one encoded in the remaining 15 bits of the address. This style of access allowed blocks of data to be more easily accessed than in systems that provided indirection solely through special instructions or index registers. One could step through memory by incrementing the address value stored in that single location in memory. This also resulted in considerable numbers of math instructions being applied to addresses, and to improve the performance of these operations, the 2650 included a second arithmetic logic unit just for address calculations.

The downside to this approach was that the high-bit was no longer part of the address, meaning the address space was only 15 bits, and the machine could access only a total of 32 KB of memory. The address space was further limited by the use of another two bits of the address to indicate the indexing mode for all logical and arithmetic (i.e. non-branch) instructions. These bits controlled functions like whether the address should be post-incremented or pre-decremented, which is extremely useful for constructing loops. But with all of these bits already accounted for, only 13 were available for addresses in these instructions, meaning only 8 KB could be addressed directly. This meant the main memory was broken up as four 8 KB blocks. To access memory outside the 8 KB where the instruction was located, the data bytes being pointed to had to contain an indirect address, pointing to some other location in memory. Doing so forced another memory read cycle, slowing performance.

When the 2650 was designed in 1972, these limitations on address space were not significant due to the small size and high cost of the static RAM memory typically used with these processors. At the time, machines typically contained 2 or 4 KB of RAM. But with the increasing use of dynamic RAM from the mid-1970s, machines with 8 and 16 KB of RAM, and ultimately 64 KB, became common and the addressing system on the 2650 became a significant hindrance.

The 2650 also contained an on-die call stack, rather than the more common solution that sets aside a location in memory to hold the stack. The stack pointer was held in three bits in the PSW. An on-die stack is much faster, as the data can be accessed directly without waiting for it to be read from external memory, but it also takes up room on the die and is always limited in size as a result of practical tradeoffs. In the 2650, the return address stack was eight 15-bit entries deep. This allowed programs to nest subroutines to eight levels.

While there were nine different addressing modes, the lack of 16-bit registers and the 13–15-bit address space prevented widespread use. Despite this, an operating system ("2650 DOS") was available, along with 8 KB and 12 KB BASIC interpreters (sold by Central Data Corporation USA), and many games of the Hunt the Wumpus style. Most programs were written in assembly language.

Uses

Signetics sold 2650-based microprocessor development boards, first the PC1001 and then its successor, the PC1500 "Adaptable Board Computer", ranging in price from A$165 to A$400. The chip by itself sold for around A$20. Several hardware construction projects and programming articles were published in magazines such as Electronics Australia and Elektor and related kits were sold by electronics stores. These factors led to its use by a number of hobbyists in many countries such as Australia, U.S.A., United Kingdom, the Netherlands and Germany.

Two types of video game console used the Signetics 2650 or 2650A. The first group of consoles are based on the Signetics 2636 video display controller; the 1292 Advanced Programmable Video System and the closely related Interton Video Computer 4000 belong to this group. Those were released in Germany in 1976 and 1978 respectively. The second group of consoles were based on the Signetics 2637 as a video display controller; Emerson Arcadia 2001 which was released in 1982 and which used a Signetics 2650 running at 0.895 MHz as a CPU belong to this group together with many other ones software-compatible (Leonardo, Hanimex MPT-03 etc.).

At least six coin-operated video games were released in the 1970s which used the 2650 CPU: Atari, Inc. Quiz Show, Meadows Games 3D Bowling, Meadows Games Gypsy Juggler, Meadows Games Lazer Command, Cinematronics Embargo, and a 1978 clone of Space Invaders by Zaccaria called The Invaders (the original by Taito uses an Intel 8080 CPU).

Italian game manufacturer Zaccaria released 28 pinball machines based on the 2650 CPU. Their successor company, MrGame, released four additional pinball machines using the 2650. Zaccaria seems to have licensed its design to Technoplay as well, and several more pinball machines were released using variations of Zaccaria's circuit board designs.

At least two coin-operated video games were released in the 1980s using the 2650. Hunchback, and Hunchback Olympic.

The processor was also used in the Signetics Instructor 50, which was a small computer designed to teach the use and programming of the Signetics 2650 CPU.

The 2650 was also used in some large items of equipment such as the Tektronix 8540, a microprocessor software development system which supported various in-circuit emulator, trace memory and logic analyser cards for real-time debugging of microprocessor systems, as practiced in the 1980s. The 2650 provided the base operating system functions, data transfer, and interface to a host computer or serial computer terminal.

The processor was most suited as a microcontroller, due to its extensive I/O support:

 * Single bit i/o pins on the processor (sense/flag bits)
 * Signals to directly address two 8-bit I/O ports (control and data ports) using single byte instructions (port i/o). This circumvented the elaborate hardware other systems needed for memory-mapped I/O
 * Signals to address another 256 I/O ports using an 8-bit address and two byte instructions, again, limiting the amount of hardware (address decoding) required. Philips emphasized this use as a micro-controller with a demonstration program showing the 2650 controlling an intelligent elevator system. Also, at trade fairs they showed the 2650 controlling a miniature 'sort and stack' robot

Industrial Microcomputer System – IMS
For a short time starting 1979, Philips sold a modular 2650 computer called the 'IMS' – Industrial Microcomputer System, based on the Eurocard format in a 19" rack. It included CPU, PROM, RAM, input, output and teletype modules. This system was meant as a more intelligent programmable logic controller. For development, they later added DEBUG, DISPLAY, INTERRUPT and MODEST ((E)PROM programmer) modules.

Architecture
The 2650 was supplied in a 40 pin plastic or ceramic DIL enclosure. An external single phase clock signal and a single 5V supply were needed.

The 2650 had many unusual features when compared to other microprocessors of the time:

 * It was a fully static NMOS 8-bit microprocessor. The static nature was unusual for the time, and meant that the processor could be halted simply by stopping the clock signal. Programmers made grateful use of this feature to "single step' through a program using a push-button switch to generate the clock pulses.
 * Unique was the 8-level 15-bit wide stack for the subroutine and interrupt return addresses which was integrated into the processor. The stack pointer used 3 bits of the upper status register. This meant subroutines and interrupts could only be nested 8 levels deep.
 * The processor had only 13 real address lines, a further 2 address lines were connected to a 2-bit 'page register', resulting in a 32 KB address space. The page register was set when an absolute (direct) branch instruction, which used a full 15-bit address, was executed. All logical and arithmetic instructions used a 13-bit address augmented by the contents of the page register, thereby limiting their scope to an 8 KB page. These 2 upper address lines were also used (multiplexed) to select the appropriate I/O port during I/O operations (Control port, Data port or Extended port).
 * Although the 2650 had only one interrupt input, this was a 'vectored' interrupt – the interrupting device needed to put a zero-relative displacement on the data bus, that would be used as the operand of a ZBSR (zero branch to subroutine relative) instruction to branch to the specified interrupt routine. Therefore, using indirect addressing, a maximum of 30 interrupt vectors could be stored in the first 64 bytes of memory. (The first three bytes were needed to hold an unconditional branch to the 'reset' routine). This vectored interrupt is also reminiscent of the PDP-11 minicomputer.

Instruction set
Although the 2650 is basically an 8-bit microprocessor, 64 opcodes are actually 9-bit, and another 32 opcodes are 11-bit (using bits in the address field). Of the remaining 128 8-bit opcodes, 124 (126 in the 2650B) are implemented, giving a total of 444 (446) instructions.

Many more instructions are available as the behavior of the standard instructions can be modified by setting or clearing status bits: WC (with or without carry) and COM (logical or arithmetic compare). This doubled the number of rotate, add, subtract and compare instructions.

The instruction set is strongly orthogonal: all logic and arithmetic instructions can use all nine addressing modes:

 * register
 * immediate
 * PC relative and PC relative indirect
 * absolute and absolute indirect
 * absolute indexed, absolute indexed with auto-increment, and absolute indexed with auto-decrement, both direct and indirect

The most significant bit of all relative and absolute addresses is used to indicate indirection.

The only exceptions are where the opcodes of meaningless operations are used for other purposes:

 * the opcode for AND register zero with register zero is used for the HALT instruction.
 * the opcode for STORE register zero into register zero is used for the NOP instruction.

Although the instruction LOAD register zero with register zero would appear meaningless, and was officially unsupported, it did set the condition code and was often used to determine the status of this register.. The Signetics Assembler generated code as if it was the instruction IORZ,R0 instead.

Indexing
With all arithmetic and logical instructions using absolute (direct) addressing, bits 14 and 13 of the address field are used to indicate the indexing mode as follows:

 * 00 no indexing
 * 01 indexing with auto increment
 * 10 indexing with auto decrement
 * 11 indexing only

When indexing is specified, the register defined in the instruction becomes the index register, and the source/destination is implicitly Register zero. For indirect indexing, Post indexing is used, i.e. the indirect address is first fetched from memory and then the index is added to it.

Branching
Probably the most mini-computer like aspect of the 2650 is the enormous number (62) of branch (jump) instructions; all these instructions could also use indirection:

 * BIRR and BIRA: Increment register and branch if non-zero (R0, R1, R2 or R3) with relative or absolute addressing
 * BDRR and BDRA: Decrement register and branch if non-zero (R0, R1, R2 or R3) with relative or absolute addressing
 * BRNR and BRNA: branch if register non-zero (R0, R1, R2 or R3) with relative or absolute addressing
 * BCTR and BCTA: branch on condition True (zero, greater-than, less-than or unconditional) with relative or absolute addressing
 * BCFR and BCFA: branch on condition False (zero, greater-than or less-than) with relative or absolute addressing.
 * ZBRR: branch relative to address zero
 * BXA: branch indexed

Like the Intel 8080, the 2650 had instructions to conditionally branch to, and return from, a subroutine:

 * BSTR and BSTA: branch to subroutine on condition True (zero, greater-than, less-than or unconditional) with relative or absolute addressing
 * BSFR and BSFA: branch to subroutine on condition False (zero, greater-than or less-than) with relative or absolute addressing
 * BSNR and BSNA: branch to subroutine if register non-zero (R0, R1, R2 or R3) with relative or absolute addressing
 * RETC: return from subroutine on condition True (zero, greater-than, less-than or unconditional)
 * RETE: return from interrupt on condition True (zero, greater-than, less-than or unconditional)
 * ZBSR: branch to subroutine relative to address zero
 * BSXA: branch to subroutine indexed

Only the branch instructions using absolute addressing used all 15 bits of the address field as address. Using such a branch instruction was, therefore, the only way to set the two bits in the page register (controlling bits 14 and 13 of the address bus) and changing the current 8 KB page.

Versions

 * 2650 original version with 1.25 MHz maximum clock frequency
 * 2650A improved version (minor fabrication changes to improve stability) 1.25 MHz maximum clock frequency
 * 2650A-1 as 2650A with 2 MHz maximum clock frequency
 * 2650B
 * 2650B-1 as 2650B with 2 MHz maximum clock frequency

The 2650B had the following changes and improvements over the 2650A:

 * Two new signals – "Bus Enable" on pin 15 and "Cycle Last" on pin 25.
 * Program Status Word Upper bits 3 and 4 are settable and testable user flags (unused on the 2650A).
 * Two new instructions STPL and LDPL to save and restore the lower status register from memory in order to simplify interrupt processing.
 * Single byte register R0 instructions execute faster (one cycle rather than two).

Second sources
In 1975, Signetics was sold to Philips and the 2650 was later incorporated into the Philips Semiconductors line. They made a version of the 2650 called the MAB2650A. Valvo, a subsidiary of Philips, sold the 2650 in Germany. Valvo also sold the VA200 single board (Eurocard) 2650 computer with 4 KB PROM/EPROM, 1 KB RAM and four I/O ports.

Other producers of licensed copies of the chip were Harris and Intersil.

Peripheral chips
The 2650 came with a full complement of peripheral chips:

 * 2621 Video Encoder (PAL)
 * 2622 Video Encoder (NTSC)
 * 2636 Programmable Video Interface
 * 2637 Universal Video Interface
 * 2651 Programmable Communication Interface
 * 2652 Multi-Protocol Communications Circuit (incl. Synchronous Data Link Control (SDLC))
 * 2653 Polynomial Generator / Checker
 * 2655 Programmable Peripheral Interface
 * 2656 SMI (System memory interface)
 * 2657 Direct Memory Access
 * 2661 Enhanced Programmable Communication Interface (EPCI)
 * 2670 Display Character and Graphics Generator
 * 2671 Programmable Keyboard and Communications Controller
 * 2672 Programmable Video Timing Controller
 * 2673 Video Attributes Controller

Many of these peripheral chips were designed so they could also be used with other microprocessors, for example the datasheet of the 2672 suggests using it with an Intel 8048 microcontroller.

Philips Technical Note 083 describes how to interface the 2651 PCI to various other microprocessors, such as the 8080, 8085, Z80, 8048 and 6800

Descendants of the 2651/2661 serial communications chips are still sold as the Philips SC26 series.

2656 System Memory Interface
The 2656 was specifically designed to augment, and interface with, the 2650 and make a 2-chip computer possible. It contained everything the 2650 lacked to make a complete computer:

 * 2 KB 8-bit mask-programmed ROM program memory
 * 128 bytes 8-bit RAM memory
 * Clock generator with crystal or RC network
 * Power-on reset
 * Eight general purpose I/O pins

The I/O pins could be used as an 8-bit I/O port or programmed to generate enable signals for extra RAM, ROM or I/O ports. This was achieved by mask-programming a Programmable Logic Array in the 2656.

To develop and test the design before committing it to production, Philips sold the PC4000, a 2656 emulator board using PROMs and FPLAs to emulate the ROM and PLA in the 2656.

title: Signetics 2650


text: User talk:81.152.107.202

title: User talk:81.152.107.202


text:
Git

Git is a distributed version control system that tracks versions of files. It is often used to control source code by programmers collaboratively developing software.

Design goals of Git include speed, data integrity, and support for distributed, non-linear workflows thousands of parallel branches running on different computers.

Git was created for use in the development of the Linux kernel by Linus Torvalds and others developing the kernel.

As with most other distributed version control systems, and unlike most client–server systems, Git maintains a local copy of the entire repository, a.k.a. repo, with history and version-tracking abilities, independent of network access or a central server. A repo is stored on each computer in a standard directory with additional, hidden files to provide version control capabilities. Git provides features to synchronize changes between repos that share history; copied (cloned) from each other. For collaboration, Git supports synchronizing with repos on remote machines. Although all repos (with the same history) are peers, developers often use a central server to host a repo to hold an integrated copy.

Git is a free and open-source software shared under the GPL-2.0-only license.

The trademark "Git" is registered by the Software Freedom Conservancy, marking its official recognition and continued evolution in the open-source community.

Today, Git is the de facto standard version control system. It is the most popular distributed version control system, with nearly 95% of developers reporting it as their primary version control system as of 2022. It is the most widely used source-code management tool among professional developers. There are offerings of Git repository services, including GitHub, SourceForge, Bitbucket and GitLab.

History
Torvalds started developing Git in April 2005 after the free license for the proprietary source-control management (SCM) system used for Linux kernel development since 2002, BitKeeper, was revoked for Linux development. The copyright holder of BitKeeper, Larry McVoy, claimed that Andrew Tridgell had created SourcePuller by reverse engineering the BitKeeper protocols. The same incident also spurred the creation of another version-control system, Mercurial.

Torvalds wanted a distributed system that he could use like BitKeeper, but none of the available free systems met his needs. He cited an example of a source-control management system needing 30 seconds to apply a patch and update all associated metadata, and noted that this would not scale to the needs of Linux kernel development, where synchronizing with fellow maintainers could require 250 such actions at once. For his design criterion, he specified that patching should take no more than three seconds, and added three more goals:
 * Take the Concurrent Versions System (CVS) as an example of what not to do; if in doubt, make the exact opposite decision.
 * Support a distributed, BitKeeper-like workflow.
 * Include very strong safeguards against corruption, either accidental or malicious.

These criteria eliminated every version-control system in use at the time, so immediately after the 2.6.12-rc2 Linux kernel development release, Torvalds set out to write his own.

The development of Git began on 3 April 2005. Torvalds announced the project on 6 April and became self-hosting the next day. The first merge of multiple branches took place on 18 April. Torvalds achieved his performance goals; on 29 April, the nascent Git was benchmarked recording patches to the Linux kernel tree at a rate of 6.7 patches per second. On 16 June, Git managed the kernel 2.6.12 release.

Torvalds turned over maintenance on 26 July 2005 to Junio Hamano, a major contributor to the project. Hamano was responsible for the 1.0 release on 21 December 2005.

Naming
Torvalds sarcastically quipped about the name git (which means "unpleasant person" in British English slang): "I'm an egotistical bastard, and I name all my projects after myself. First 'Linux', now 'git'." The man page describes Git as "the stupid content tracker".

The read-me file of the source code elaborates further:

""git" can mean anything, depending on your mood.
 * Random three-letter combination that is pronounceable, and not actually used by any common UNIX command. The fact that it is a mispronunciation of "get" may or may not be relevant.
 * Stupid. Contemptible and despicable. Simple. Take your pick from the dictionary of slang.
 * "Global information tracker": you're in a good mood, and it actually works for you. Angels sing, and a light suddenly fills the room.
 * "Goddamn idiotic truckload of sh*t": when it breaks."

The source code for Git refers to the program as "the information manager from hell".

Design
Git's design is a synthesis of Torvalds's experience with Linux in maintaining a large distributed development project, along with his intimate knowledge of file-system performance gained from the same project and the urgent need to produce a working system in short order. These influences led to the following implementation choices:
 * Strong support for non-linear development: Git supports rapid branching and merging, and includes specific tools for visualizing and navigating a non-linear development history. In Git, a core assumption is that a change will be merged more often than it is written, as it is passed around to various reviewers. In Git, branches are very lightweight: a branch is only a reference to one commit.
 * Distributed development: Like Darcs, BitKeeper, Mercurial, Bazaar, and Monotone, Git gives each developer a local copy of the full development history, and changes are copied from one such repository to another. These changes are imported as added development branches and can be merged in the same way as a locally developed branch.
 * Compatibility with existing systems and protocols: Repositories can be published via Hypertext Transfer Protocol Secure (HTTPS), Hypertext Transfer Protocol (HTTP), File Transfer Protocol (FTP), or a Git protocol over either a plain socket or Secure Shell (ssh). Git also has a CVS server emulation, which enables the use of existing CVS clients and IDE plugins to access Git repositories. Subversion repositories can be used directly with git-svn.
 * Efficient handling of large projects: Torvalds has described Git as being very fast and scalable, and performance tests done by Mozilla showed that it was an order of magnitude faster diffing large repositories than Mercurial and GNU Bazaar; fetching version history from a locally stored repository can be one hundred times faster than fetching it from the remote server.
 * Cryptographic authentication of history: The Git history is stored in such a way that the ID of a particular version (a commit in Git terms) depends upon the complete development history leading up to that commit. Once it is published, it is not possible to change the old versions without it being noticed. The structure is similar to a Merkle tree, but with added data at the nodes and leaves. (Mercurial and Monotone also have this property.)
 * Toolkit-based design: Git was designed as a set of programs written in C and several shell scripts that provide wrappers around those programs. Although most of those scripts have since been rewritten in C for speed and portability, the design remains, and it is easy to chain the components together.
 * Pluggable merge strategies: As part of its toolkit design, Git has a well-defined model of an incomplete merge, and it has multiple algorithms for completing it, culminating in telling the user that it is unable to complete the merge automatically and that manual editing is needed.
 * Garbage accumulates until collected: Aborting operations or backing out changes will leave useless dangling objects in the database. These are generally a small fraction of the continuously growing history of wanted objects. Git will automatically perform garbage collection when enough loose objects have been created in the repository. Garbage collection can be called explicitly using.
 * Periodic explicit object packing: Git stores each newly created object as a separate file. Although individually compressed, this takes up a great deal of space and is inefficient. This is solved by the use of packs that store a large number of objects delta-compressed among themselves in one file (or network byte stream) called a packfile. Packs are compressed using the heuristic that files with the same name are probably similar, without depending on this for correctness. A corresponding index file is created for each packfile, telling the offset of each object in the packfile. Newly created objects (with newly added history) are still stored as single objects, and periodic repacking is needed to maintain space efficiency. The process of packing the repository can be very computationally costly. By allowing objects to exist in the repository in a loose but quickly generated format, Git allows the costly pack operation to be deferred until later, when time matters less, e.g., the end of a workday. Git does periodic repacking automatically, but manual repacking is also possible with the  command. For data integrity, both the packfile and its index have an SHA-1 checksum inside, and the file name of the packfile also contains an SHA-1 checksum. To check the integrity of a repository, run the   command.

Another property of Git is that it snapshots directory trees of files. The earliest systems for tracking versions of source code, Source Code Control System (SCCS) and Revision Control System (RCS), worked on individual files and emphasized the space savings to be gained from interleaved deltas (SCCS) or delta encoding (RCS) the (mostly similar) versions. Later revision-control systems maintained this notion of a file having an identity across multiple revisions of a project. However, Torvalds rejected this concept. Consequently, Git does not explicitly record file revision relationships at any level below the source-code tree.

Downsides
These implicit revision relationships have some significant consequences:
 * It is slightly more costly to examine the change history of one file than the whole project. To obtain a history of changes affecting a given file, Git must walk the global history and then determine whether each change modified that file. This method of examining history does, however, let Git produce with equal efficiency a single history showing the changes to an arbitrary set of files. For example, a subdirectory of the source tree plus an associated global header file is a very common case.
 * Renames are handled implicitly rather than explicitly. A common complaint with CVS is that it uses the name of a file to identify its revision history, so moving or renaming a file is not possible without either interrupting its history or renaming the history and thereby making the history inaccurate. Most post-CVS revision-control systems solve this by giving a file a unique long-lived name (analogous to an inode number) that survives renaming. Git does not record such an identifier, and this is claimed as an advantage. Source code files are sometimes split or merged, or simply renamed, and recording this as a simple rename would freeze an inaccurate description of what happened in the (immutable) history. Git addresses the issue by detecting renames while browsing the history of snapshots rather than recording it when making the snapshot. (Briefly, given a file in revision N, a file of the same name in revision N − 1 is its default ancestor. However, when there is no like-named file in revision N − 1, Git searches for a file that existed only in revision N − 1 and is very similar to the new file.) However, it does require more CPU-intensive work every time the history is reviewed, and several options to adjust the heuristics are available. This mechanism does not always work; sometimes a file that is renamed with changes in the same commit is read as a deletion of the old file and the creation of a new file. Developers can work around this limitation by committing the rename and the changes separately.

Merging strategies
Git implements several merging strategies; a non-default strategy can be selected at merge time:
 * resolve: the traditional three-way merge algorithm.
 * recursive: This is the default when pulling or merging one branch, and is a variant of the three-way merge algorithm. "When there are more than one common ancestors that can be used for a three-way merge, it creates a merged tree of the common ancestors and uses that as the reference tree for the three-way merge. This has been reported to result in fewer merge conflicts without causing mis-merges by tests done on prior merge commits taken from Linux 2.6 kernel development history. Also, this can detect and handle merges involving renames."

- Linus Torvalds

 * octopus: This is the default when merging more than two heads.

Data structures
Git's primitives are not inherently a source-code management system. Torvalds explains: "In many ways you can just see git as a filesystem—it's content-addressable, and it has a notion of versioning, but I really designed it coming at the problem from the viewpoint of a filesystem person (hey, kernels is what I do), and I actually have absolutely zero interest in creating a traditional SCM system."

From this initial design approach, Git has developed the full set of features expected of a traditional SCM, with features mostly being created as needed, then refined and extended over time.

Git has two data structures: a mutable index (also called stage or cache) that caches information about the working directory and the next revision to be committed; and an object database that stores immutable objects.

The index serves as a connection point between the object database and the working tree.

The object store contains five types of objects:
 * A blob is the content of a file. Blobs have no proper file name, time stamps, or other metadata (a blob's name internally is a hash of its content). In Git, each blob is a version of a file, in which is the file's data.
 * A tree object is the equivalent of a directory. It contains a list of file names, each with some type bits and a reference to a blob or tree object that is that file, symbolic link, or directory's contents. These objects are a snapshot of the source tree. (In whole, this comprises a Merkle tree, meaning that only a single hash for the root tree is sufficient and actually used in commits to precisely pinpoint to the exact state of whole tree structures of any number of sub-directories and files.)
 * A commit object links tree objects together into history. It contains the name of a tree object (of the top-level source directory), a timestamp, a log message, and the names of zero or more parent commit objects.
 * A tag object is a container that contains a reference to another object and can hold added meta-data related to another object. Most commonly, it is used to store a digital signature of a commit object corresponding to a particular release of the data being tracked by Git.
 * A packfile object collects various other objects into a zlib-compressed bundle for compactness and ease of transport over network protocols.

Each object is identified by a SHA-1 hash of its contents. Git computes the hash and uses this value for the object's name. The object is put into a directory matching the first two characters of its hash. The rest of the hash is used as the file name for that object.

Git stores each revision of a file as a unique blob. The relationships between the blobs can be found through examining the tree and commit objects. Newly added objects are stored in their entirety using zlib compression. This can consume a large amount of disk space quickly, so objects can be combined into packs, which use delta compression to save space, storing blobs as their changes relative to other blobs.

Additionally, Git stores labels called refs (short for references) to indicate the locations of various commits. They are stored in the reference database and are respectively:
 * Heads (branches): Named references that are advanced automatically to the new commit when a commit is made on top of them.
 * HEAD: A reserved head that will be compared against the working tree to create a commit.
 * Tags: Like branch references but fixed to a particular commit. Used to label important points in history.

Commands
Frequently used commands for Git's command-line interface include:

A .gitignore file may be created in a Git repository as a plain text file. The files listed in the .gitignore file will not be tracked by Git. This feature can be used to ignore files with keys or passwords, various extraneous files, and large files (which GitHub will refuse to upload).
 * , which is used to create a git repository.
 * , which clones, or duplicates, a git repository from an external URL.
 * , which adds a file to git's working directory (files about to be committed).
 * , which commits the files from the current working directory (so they are now part of the repository's history).

Git references
Every object in the Git database that is not referred to may be cleaned up by using a garbage collection command or automatically. An object may be referenced by another object or an explicit reference. Git has different types of references. The commands to create, move, and delete references vary. lists all references. Some types are:
 * heads: refers to an object locally,
 * remotes: refers to an object which exists in a remote repository,
 * stash: refers to an object not yet committed,
 * meta: e.g. a configuration in a bare repository, user rights; the refs/meta/config namespace was introduced retrospectively, gets used by Gerrit,
 * tags: see above.

Implementations

Git (the main implementation in C) is primarily developed on Linux, although it also supports most major operating systems, including the BSDs (DragonFly BSD, FreeBSD, NetBSD, and OpenBSD), Solaris, macOS, and Windows.

The first Windows port of Git was primarily a Linux-emulation framework that hosts the Linux version. Installing Git under Windows creates a similarly named Program Files directory containing the Mingw-w64 port of the GNU Compiler Collection, Perl 5, MSYS2 (itself a fork of Cygwin, a Unix-like emulation environment for Windows) and various other Windows ports or emulations of Linux utilities and libraries. Currently, native Windows builds of Git are distributed as 32- and 64-bit installers. The git official website currently maintains a build of Git for Windows, still using the MSYS2 environment.

The JGit implementation of Git is a pure Java software library, designed to be embedded in any Java application. JGit is used in the Gerrit code-review tool, and in EGit, a Git client for the Eclipse IDE.

Go-git is an open-source implementation of Git written in pure Go. It is currently used for backing projects as a SQL interface for Git code repositories and providing encryption for Git.

Dulwich is an implementation of Git written in pure Python with support for CPython 3.6 and later and Pypy.

The libgit2 implementation of Git is an ANSI C software library with no other dependencies, which can be built on multiple platforms, including Windows, Linux, macOS, and BSD. It has bindings for many programming languages, including Ruby, Python, and Haskell.

JS-Git is a JavaScript implementation of a subset of Git.

GameOfTrees is an open-source implementation of Git for the OpenBSD project.

Git server

As Git is a distributed version control system, it could be used as a server out of the box. It is shipped with a built-in command  which starts a simple TCP server running on the Git protocol. Dedicated Git HTTP servers help (amongst other features) by adding access control, displaying the contents of a Git repository via the web interfaces, and managing multiple repositories. Already existing Git repositories can be cloned and shared to be used by others as a centralized repo. It can also be accessed via remote shell just by having the Git software installed and allowing a user to log in. Git servers typically listen on TCP port 9418.

Open source

 * Hosting the Git server using the Git Binary.
 * Gerrit, a Git server configurable to support code reviews and provide access via ssh, an integrated Apache MINA or OpenSSH, or an integrated Jetty web server. Gerrit provides integration for LDAP, Active Directory, OpenID, OAuth, Kerberos/GSSAPI, X509 https client certificates. With Gerrit 3.0 all configurations will be stored as Git repositories, and no database is required to run. Gerrit has a pull-request feature implemented in its core but lacks a GUI for it.
 * Phabricator, a spin-off from Facebook. As Facebook primarily uses Mercurial, Git support is not as prominent.
 * RhodeCode Community Edition (CE), supporting Git, Mercurial and Subversion with an AGPLv3 license.
 * Kallithea, supporting both Git and Mercurial, developed in Python with GPL license.
 * External projects like gitolite, which provide scripts on top of Git software to provide fine-grained access control.
 * There are several other FLOSS solutions for self-hosting, including Gogs, Gitea, a fork of Gogs, as well as Forgejo, which is, in turn, a fork of Gitea. Gogs, as well as the two aforementioned derivatives of it, is developed using the Go language. All three solutions are made available under the MIT license.

Git server as a service
There are many offerings of Git repositories as a service. The most popular are GitHub, SourceForge, Bitbucket and GitLab.

Graphical interfaces
Git comes with a Tcl/Tk GUI, which allows users to perform actions such as creating and amending commits, creating and merging branches, and interacting with remote repositories.

In addition to the official GUI, many 3rd party interfaces exist that provide similar features to the official GUI distributed with Git, such as GitHub Desktop, SourceTree, and TortoiseGit.

Adoption
The Eclipse Foundation reported in its annual community survey that as of May 2014, Git is now the most widely used source-code management tool, with 42.9% of professional software developers reporting that they use Git as their primary source-control system compared with 36.3% in 2013, 32% in 2012; or for Git responses excluding use of GitHub: 33.3% in 2014, 30.3% in 2013, 27.6% in 2012 and 12.8% in 2011. Open-source directory Black Duck Open Hub reports a similar uptake among open-source projects.

Stack Overflow has included version control in their annual developer survey in 2015 (16,694 responses), 2017 (30,730 responses), 2018 (74,298 responses) and 2022 (71,379 responses). Git was the overwhelming favorite of responding developers in these surveys, reporting as high as 93.9% in 2022.

Version control systems used by responding developers: The UK IT jobs website itjobswatch.co.uk reports that as of late September 2016, 29.27% of UK permanent software development job openings have cited Git, ahead of 12.17% for Microsoft Team Foundation Server, 10.60% for Subversion, 1.30% for Mercurial, and 0.48% for Visual SourceSafe.

Extensions
There are many Git extensions, like Git LFS, which started as an extension to Git in the GitHub community and is now widely used by other repositories. Extensions are usually independently developed and maintained by different people, but at some point in the future, a widely used extension can be merged with Git.

Other open-source Git extensions include:

 * git-annex, a distributed file synchronization system based on Git
 * git-flow, a set of Git extensions to provide high-level repository operations for Vincent Driessen's branching model
 * git-machete, a repository organizer & tool for automating rebase/merge/pull/push operations

Microsoft developed the Virtual File System for Git (VFS for Git; formerly Git Virtual File System or GVFS) extension to handle the size of the Windows source-code tree as part of their 2017 migration from Perforce. VFS for Git allows cloned repositories to use placeholders whose contents are downloaded only once a file is accessed.

Conventions
Git can be used in a variety of different ways, but some conventions are commonly adopted.

 * The command to create a local repo, git init, creates a branch named master. Often it is used as the integration branch for merging changes into. Since the default upstream remote is named origin, the default remote branch is origin/master. Some tools such as GitHub and GitLab create a default branch named main instead. Also, users can add and delete branches and choose any branch for integrating.
 * Pushed commits generally are not overwritten, but are reverted by committing another change which reverses an earlier commit. This prevents shared commits from being invalid because the commit on which they are based does not exist in the remote. If the commits contain sensitive information, they should be removed, which involves a more complex procedure to rewrite history.
 * The git-flow workflow and naming conventions are often adopted to distinguish feature-specific unstable histories (feature/*), unstable shared histories (develop), production-ready histories (main), and emergency patches to released products (hotfix).
 * A pull request, a.k.a. merge request, is a request by a user to merge a branch into another branch. Git does not itself provide for pull requests, but it is a common feature of git cloud services. The underlying function of a pull request is no different than that of an administrator of a repository pulling changes from another remote (the repository that is the source of the pull request). However, the pull request itself is a ticket managed by the hosting server which perform these actions; it is not a feature of git SCM.

Security
Git does not provide access-control mechanisms, but was designed for operation with other tools that specialize in access control.

On 17 December 2014, an exploit was found affecting the Windows and macOS versions of the Git client. An attacker could perform arbitrary code execution on a target computer with Git installed by creating a malicious Git tree (directory) named .git (a directory in Git repositories that stores all the data of the repository) in a different case (such as .GIT or .Git, needed because Git does not allow the all-lowercase version of .git to be created manually) with malicious files in the .git/hooks subdirectory (a folder with executable files that Git runs) on a repository that the attacker made or on a repository that the attacker can modify. If a Windows or Mac user pulls (downloads) a version of the repository with the malicious directory, then switches to that directory, the .git directory will be overwritten (due to the case-insensitive trait of the Windows and Mac filesystems) and the malicious executable files in .git/hooks may be run, which results in the attacker's commands being executed. An attacker could also modify the .git/config configuration file, which allows the attacker to create malicious Git aliases (aliases for Git commands or external commands) or modify extant aliases to execute malicious commands when run. The vulnerability was patched in version 2.2.1 of Git, released on 17 December 2014, and announced the next day.

Git version 2.6.1, released on 29 September 2015, contained a patch for a security vulnerability that allowed arbitrary code execution. The vulnerability was exploitable if an attacker could convince a victim to clone a specific URL, as the arbitrary commands were embedded in the URL itself. An attacker could use the exploit via a man-in-the-middle attack if the connection was unencrypted, as they could redirect the user to a URL of their choice. Recursive clones were also vulnerable since they allowed the controller of a repository to specify arbitrary URLs via the gitmodules file.

Git uses SHA-1 hashes internally. Linus Torvalds has responded that the hash was mostly to guard against accidental corruption, and the security a cryptographically secure hash gives was just an accidental side effect, with the main security being signing elsewhere. Since a demonstration of the SHAttered attack against git in 2017, git was modified to use a SHA-1 variant resistant to this attack. A plan for hash function transition is being written since February 2020.

Trademark
"Git" is a registered word trademark of Software Freedom Conservancy under US500000085961336 since 2015-02-03.

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Felicia Forrester

Felicia Forrester is a fictional character from the CBS Daytime soap opera The Bold and the Beautiful. Originally portrayed by actress Colleen Dion-Scotti, the role was portrayed on and off by Lesli Kay from November 2005 to 2014, with a brief reappearance in September 2016.

The youngest daughter of Stephanie (Susan Flannery) and Eric Forrester (John McCook), Felicia has one brother, Thorne (Winsor Harmon), and one sister, Kristen Forrester (Terri Ann Linn, Tracy Melchior). She had another sister, Angela who is deceased. She also has three half-siblings: Ridge (Thorsten Kaye), Rick (Jacob Young), and Bridget (Ashley Jones). She is affectionately known as Fifi, a name bestowed on her by her mother's friend, Sally Spectra (Darlene Conley). In March and April 2008, the character made her first crossover to the series' sister series, The Young and the Restless.

Casting and conception
The role of Felicia Forrester was originally cast with actress Colleen Dion-Scotti in 1989; first appearing on January 15, 1990. Dion-Scotti remained until 1992 but briefly returned in 1997. In May 2004, it was announced that Dion-Scotti was again returning in an attempt to "reinvent" the Forresters. That September, the actress was bumped to recurring status due to the actress' commute between the east coast and the west coast, where the series films. In October, the actress announced that she would be exiting the series once again. Her final appearance was on December 4, 2004.

In October 2005, it was announced that another daytime veteran actress, Lesli Kay, had been hired as a recast Felicia. Kay was best known for her roles as Molly Conlan on As the World Turns, and also known as Lois Cerullo on General Hospital. Her first airdate as Felicia was November 30, 2005, opposite Taylor Hayes (Hunter Tylo).

In 2008, it was announced that Kay would crossover to The Young and the Restless, in what was considered to be a semi-permanent basis. Kay's crossover to Y&R was short-lived and she returned to her home series. In 2009, it was announced that Kay would make history in becoming the first actress to hold two roles on two separate coasts, when she was announced to be returning to the role of Molly on As the World Turns, while maintaining her role as Felicia. Following the cancellation of As the World Turns, Kay continued appearing on B&B.

In August 2014, Kay reprised her role as Felicia for one episode of The Bold and the Beautiful. A TV Soap reporter said that Kay had no more upcoming appearances scheduled. On September 2, 2016, it was announced that Kay would again reprise her portrayal of Felicia on September 22, 23, and 26.

Storylines
Soon after Felicia's arrival in Los Angeles in 1990, she forges ill-fated relationships with Jake Maclaine (Todd McKee) and Zach Hamilton (Michael Watson). She leaves town in 1992. Felicia returns in 1997 for her parents' wedding, which is called off when Eric's affair with Lauren Fenmore (Tracey E. Bregman) is exposed. After Ridge is arrested for shooting Grant Chambers (Charles Grant), Felicia tries to help exonerate him and attempts to help him reunite with his wife, Taylor Hayes (Hunter Tylo). She is unsuccessful on both counts, and leaves town again. After seven years overseas, Felicia returns in July 2004. She has an affair with Nick Marone (Jack Wagner), who soon discovers that Felicia had colon cancer. She has medical tests run and is given the all clear. Felicia realizes that she and Nick will not work out and she leaves for Paris.

Felicia returns a year later with a baby son. She believes the baby is Nick's, having named him Dominick. It is revealed that Dominick is the product of a one-night stand with Dante Damiano (Antonio Sabàto, Jr.) in Paris, leaving Nick devastated. Felicia's cancer returns and she "dies" in her mother's arms. However, a faint heartbeat is detected in the ambulance and Stephanie has Felicia secretly transferred to a private clinic, where she eventually has a liver transplant. Felicia fights to survive for her child's sake. Meanwhile, Dante and Bridget, believing that Felicia is dead, begin raising Dominick (who they nicknamed "Dino") as a family. Stephanie eventually reveals to the rest of the family that Felicia is alive. Though ecstatic to have her back, Bridget and Dante prepare to fight Felicia for custody of Dino. However, Dino bonds together Dante and Felicia instead, and Bridget gives up on Dante. Dante proposes to Felicia, although he is still in love with Bridget. On their wedding day, Felicia sees Bridget staring at Dante and a heated confrontation ensues. Bridget then admits her love for Dante and they temporarily reunite. Dante and Bridget eventually split again because of her reluctance to have kids right away, and Felicia and Dante get back together. Bridget later finds out that she is pregnant with Dante's child, but she later miscarries the baby, with Felicia and Dante supporting her through the loss. Despite Bridget stepping aside for Felicia to reunite with Dante, an act which solidified the sisters once more, Felicia develops animosity towards Dante, now living in Italy, calling him a loser. Felicia works with Katie Logan (Heather Tom) to try to end the long-time war that had ensued between their families. Felicia clashes with her father when he divorces Stephanie and marries Donna Logan (Jennifer Gareis).

Felicia visits Genoa City to assist Nick Newman (Joshua Morrow) in the launch of Restless Style magazine. While working on the joint campaign, Felicia flirts with Nick, and joins forces with Nick's half-brother Adam (Chris Engen) to break up Nick and his wife Phyllis Summers Newman (Michelle Stafford), which is unsuccessful.

Felicia returns to Los Angeles and allies with Thorne and Ridge to eliminate Donna out of Forrester Creations, because of the supposed bad publicity that the company had received since Eric married Donna (of whom none of them approve of). Their efforts are not well received by Eric, who is angry that his children aren't willing to give Donna a chance. The feud continues and Felicia is fired from her job at Forrester Creations by Donna, though she is later reinstated. Felicia becomes frustrated with her father's choice to name Rick president of the company even though. She sees the Logan family as having far too much influence over her family's business, and feels that her father does not notice her anymore. When it is time for the company to debut its new line, Felicia openly expresses that she partially wishes it would fail so that Eric would see the error in allowing the Logan family to have so much power over Forrester Creations. Felicia contacts Nick expressing a wish to leave her father's company in favor of Jackie M and even offers to rekindle their romance, despite him being engaged to Katie Logan (Heather Tom). It does not happen because Nick is committed to Katie.

Felicia returns in 2010 and learns her mother has cancer, and stays to support the family until Christmas. She again returns in July of the following year for the wedding of Ridge and Taylor—which does not end up happening. Felicia returns in November 2012 for her mother's farewell party, she stays for the funeral and leaves again after spending Christmas with her family. In August 2014, Wyatt Spencer (Darin Brooks), Hope Logan (Kim Matula) and Rick (Jacob Young) visit Felicia at Forrester Creations Paris, ahead of shooting a new promotion in the city. In September 2016, Felicia returns to help her family to stop Eric and Quinn Fuller (Rena Sofer)'s wedding.

Reception
Kay's performance in the role earned her a nomination for the Daytime Emmy Award for Outstanding Supporting Actress in a Drama Series in 2007. Luke Kerr from Daytime Confidential expressed excitement for Felicia's 2011 return, writing "This is going to be fun!", hoping that Felicia "stirs up some trouble while she’s back". In 2014, Jillian Bowe from the same website called Felicia a "fiesty fashionista and cancer survivor".

title: Felicia Forrester


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title: User talk:71.96.250.184