Talk:7400-series integrated circuits

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Is it just me or does the article look a wee bit like someone snuck some Potato Semiconductors advertisement in? —Preceding unsigned comment added by 131.188.212.202 (talk) 13:05, 30 January 2008 (UTC)
 * I assume this ad is gone now and this comment can be removed? I don't see anything about potato anymore. JettaMann (talk) 13:26, 8 November 2010 (UTC)

IC logic
The opening sentence reads "The 7400 series of TTL integrated circuits are historically important as the first widespread family of IC logic". With no definition of what IC logic is. Integrated Circuit? This should be defined for the non-expert. Or at least linked. Bilz0r 23:54, 3 September 2007 (UTC)

Logic Families?
Could someone do more research on the different families of logic? http://www.ti.com/ (http://focus.ti.com/logic/docs/technologyfamily.tsp?templateId=5985&navigationId=11386&DCMP=TIHomeTracking&HQS=Other+OT+home_p_logictechfam) has an extensive list of logic families. Also, additions like the 'A' prefix sometimes means Advanced, and the 'H' suffix means bus hold, etc. could be improved. Mhowell 14:25, 17 October 2005 (UTC)

List of 7400 series parts doesn't really belong in Talk; moved to list of 7400 series integrated circuits. --Brouhaha 16:24, 29 Sep 2004 (UTC)

Minicomputers Using 7400 series TTL
The 74181 was the 'workhorse' of the minicomputer era. It was the function generator for machines like the:
 * DEC PDP

Introduction date and early pricing
The main page states that the 7400 was available in 1962. I believe this is incorrect. I'm pretty sure that it was introduced around 1966-1967, but I don't have an authoritative reference. Note that there were other TTL parts before the 7400 series (e.g., the Motorola MTTL 4000 series, not to be confused with the CD4000 CMOS series). --Brouhaha 15:23, 29 Sep 2004 (UTC)

Updated introduction date to 1965; I've found two references to TI introducing the SN7400 series in that year, although neither could be considered extremely authoritative. The only logic *family* in 1962 was Motorola MECL. I'm not sure whether the "nearly $1000" price is accurate, nor the engineer's typical salary. --Brouhaha 23:49, 4 Oct 2004 (UTC)

Removed $1000 claim. I've spoken to engineers that were designing computers in 1965, and they say the early SN7400 prices were well under $100, possibly under $25. --Brouhaha 19:50, 18 Jan 2005 (UTC)

I still haven't found any definitive pricing information from 1965, but SN5400 series parts (military-grade version of SN7400) appeared on page 35 of the Allied Industrial Electronics Catalog #660 (1966). Parts listed are the SN5400, SN5410, SN5420, SN5430, SN5440, SN5450, SN5460, and SN5470. Quantity 1-24 price from Allied ranged from $17.70 to $28.80. --Brouhaha (talk) 05:54, 29 September 2009 (UTC)

(Non-) use in Minuteman II missile
I removed the following paragraph as it has NOTHING to do with 7400 series TTL, which was not used in the Minuteman II: The computer for the Minuteman II missile used integrated circuits in such large quantities that the prices fell to only $15 per package of four gates, paying for the difficult new lithographic assembly lines, and enabling the sharply-reducing prices of the modern digital computer. --Brouhaha 23:49, 4 Oct 2004 (UTC)

TI sold the "Minuteman" series DTL integrated circuits, SN336A through SN355A and SN717A; they were listed on page 21 of the Allied Industrial Electronics Catalog #650 (1965), and page 35 Catalog #660 (1966), but are not listed in Catalog #680 (1968). No relation to 7400 series. --Brouhaha (talk) 05:54, 29 September 2009 (UTC)

Transistor Count?
From the diagram, am I correct in thinking this product had only 4 transistors in it?
 * MSTCrow 18:30, 17 March 2006 (UTC)
 * No, the diagram shows 4 NAND gates. Each gate is implemented in typically 4 transistors (a few more for AND, NOR, OR gates etc) for a total of 16 transistors in the 7400. Four of these transistors has two emitters in it, so you might want to count those as say 1.3 transistors (4 connections to the usual 3). An eight input NAND gate (7430) has just 4 transistors, but one of these has 8 emitters (which you might want to count as 10/3, so only about 6.3 transistor equivalents in that one. These are the SSI chips (small scale integration). Things like the 7490 counter are called MSI (medium scale integration), they have maybe a hundred transistors in them. --Mike Van Emmerik 22:30, 17 March 2006 (UTC)

pictures
Do the pictures of the homebrew projects add anything to the article? They seem irrelevant to me. -- Mikeblas 11:52, 26 March 2007 (UTC)


 * Yes somewhat irrelevant, and also in the TTL article. It would be natural with, say, a picture of an older (all TTL) mini-computer or IBM-PC board, along with one that shows surface mounted 74-series chips supporting large ICs (and/or usage in consumer electronics). I guess a couple of current pictures could as well be kept though (as "curiosa"), or used in other appropriate articles. HenkeB 07:55, 28 April 2007 (UTC)
 * I've removed them, then. -- Mikeblas 19:14, 9 June 2007 (UTC)

7400 Originator
Um, so who introduced the 7400 series? - MSTCrow 16:56, 14 June 2007 (UTC)


 * Texas Instruments, I think. -- Mikeblas 16:57, 14 June 2007 (UTC)


 * But see Transistor-transistor logic article for the history of TTL; which cites the Computer Museum web site. TTL was invented in 1961, and although TI made the biggest family of parts, there were many manufacturers in the TTL business in the early years (including Westinghouse- remember Westinghouse?). TTL and 7400 series weren't quite synonomous. --Wtshymanski (talk) 14:41, 21 April 2008 (UTC)


 * FWIW...back in the 80's when I was a hobbyist, I read that Texas instruments originated the 7400 series for our space program. — Preceding unsigned comment added by 67.241.83.46 (talk) 00:40, 3 September 2011 (UTC)


 * I too was wondering (2019-4-7) what the origin of the 74 prefix was; I'd wondered if it was the year 1974, but seems it was around in the late '60s, so not that. Could be the fourth variant in the 7000 series (see section below), but it's not clear whether that is the case, and even if it is, it would beg the question of where that "name" came from. — Preceding unsigned comment added by G6JPG (talk • contribs) 15:26, 7 April 2019 (UTC)


 * 1) The 74 prefix doesn't have anything to do with the year 1974, because in the "Further Reading" section there are 7400 series parts in the 1967 Texas Instruments catalog and 1971 book. 2) Texas Instruments SN7400 family is commercial (and industrial) temperature range parts, SN5400 family is similar parts in military temperature range parts. 3) Most likely 7400 series wasn't used in space, instead 5400 military parts would be more likely.  4) See Transistor–transistor logic for more historical information.  •  Sbmeirow  •  Talk  • 18:29, 7 April 2019 (UTC)

Some early history
I found this interesting story about an early use of the 7400 series in a mixed analog-digital application. There might be something in there worth mentioning in the article. -- RoySmith (talk) 17:05, 14 June 2007 (UTC)

Other 7000 series logic families
In the early 1980's, I ran across a parts bin with other 7000 series devices. Might have been 7200s or 7300s, I can't remember. Anyway, we pried the tops off of some of these, took some photomicrographs and determined these were discrete logic devices analogous to 7400s. Later, I found some some data books (maybe TI, can't remember) that confirmed these were DTL devices. It seemed that the 7400 series was the latest (and most successful) of these 7000 series. We all know the limitations of DTL, so that's what probably led to 7400 TTL devices.

Also, TI had some 7500 devices as I recall. I didn't have any docs on these, but I did see them used on some large wire wrapped logic boards in the 70's and 80's. The ones I remember were 8 pin DIPs, looked liked line drivers, level converters, or related logic interface.

What about 7600s? The classic SN76477 and SN76488 come to mind.

Does anyone have any more info on this? Madhu (talk) 21:50, 31 December 2007 (UTC)

Standard component
It's overstated to say that 7400 series TTL chips were standard components for 40 years in many products besides computers. Hardly anything had 7400 chips in it in 1968 *besides* computers. Hardly anything *today* has 7400 series chips in it. Even at its peak popularity, it was not hard to find for example especially consumer electronics that had no TTL in it. The phrase irritates me because it's vacuous and content-free and not even particularly descriptive, and not true. --Wtshymanski (talk) 16:15, 14 January 2008 (UTC)


 * Well, I can live with your edits, however, the text didn't say that exactly, "...standard-components for more than 40 years, and seen use in many types of products and equipment besides computers." was intended to state two separate things: (1) the 7400 series has defined standard functions and pin-configs. since long, and, (2) the chips have been used in many other apparatus than computers. Hardly untrue. / HenkeB (talk) 17:03, 14 January 2008 (UTC)


 * I'd also like to see a citation for the first widespread family of integrated circuit logic. Certainly, it was widespread, but it is really true that it was the first?  Probably, but it needs a verifiable citation.  -- RoySmith (talk) 16:26, 14 January 2008 (UTC)
 * I just hit a few of my books; for example Don Lancaster refers to the RTL family, and ECL was also made before 7400 series. "Widespread"is difficult to nail down. --Wtshymanski (talk) 17:31, 14 January 2008 (UTC)

Failure statistics
I'm not sure exactly where (or if) it belongs in the article, but there's some interesting information about failure modes of 7400 (and other) logic chips used in early video games at. -- RoySmith (talk) 20:57, 14 January 2008 (UTC) link is now defunct! Mahjongg (talk) 22:25, 27 April 2013 (UTC)

Sources for references...
-- RoySmith (talk) 21:00, 14 January 2008 (UTC)

6400 series
Can't find any reference to a "6400" industrial series in my 1973 first edition TI TTL handbook, nor in my 1975 edition of the Don Lancaster book, nor in my 1988 edition of the TI databook. Even a Google search only turns up this Wikipedia page and its hangers-on. I'm taking it out till someone can find a reference. --Wtshymanski (talk) 02:36, 21 April 2008 (UTC)
 * It seems there was enough interest in the 6400 series parts that Mullard had a line of interchangeable TTL parts to substitute for them. They must have been sold for a very short time because they don't appear in my TTL Data Book - but the Mullard data sheets are dates 1970, just a little older than my book. So, it's going back in, with a reference this time. --Wtshymanski (talk) 00:02, 17 May 2008 (UTC)

Nostalgia
This article makes me feel nostalgic for the first chip I ever bought, a 7400. Gvanrossum (talk) 00:09, 2 May 2009 (UTC)

Soviet Union's K155xxxx series and other Eastern Block
The article mentions very briefly К155ЛА3 as equivalent to 7400 stressing mainly on metric pinout. It might be useful to mention that the whole line of 74xx ICs was made in the USSR:
 * К155xxx(x) series was fully functional equivalent across the 74xx(x) series - 7420 was К155ЛА1, 7402 was К155ЛЕ1, 7474 was К155ТМ2, 7490/92/93/193 were К155ИЕ2/ИЕ4/ИЕ5/ИЕ7 respectively, etc.
 * other series as equivalents to technology modifications of the basic 74xx - 74Sxx(x) was К531xxx(x), 74LSxx(x) was К555xxx(x), 74AS was К1530, 74F was К1531, 74ALS was К1533, 74HC was К1564, etc.

It also could be noted that various subsets of 7400 were made by Bulgaria, Czechoslovakia, East Germany, Hungary and Poland. --192.28.65.210 (talk) 14:45, 13 August 2010 (UTC)
 * This is very interesting, the problem is finding (hopefully English-language) sources to cite for it. --Wtshymanski (talk) 15:38, 13 August 2010 (UTC)
 * "finding" is the easy part, there are tens or even hundreds of sources. the hard part is right behind the word "hopefully". if one googles the russian part numbers (paying attention to use cyrillic "К" and not the latin "K") many hits will come up as both 7400 series and their russian counterparts are still manifactured and sold. many more paper books have described the series.
 * 74xx equivalents: ,
 * 74/74H/74L/74S/74LS/74ALS equivalents:, , etc.
 * even radiation-resistant 54HC equivalents:
 * it is worth noticing that soviet/russian marking system differs from the western one. there is no manifacturer prefix (there was only one, the USSR), and the prefix shows the case and temperature range. for example К155ЛА3 is plastic case with generic (0÷70°C) range while КМ155ЛА3 is ceramic case with industry (-25 ÷ +85°C) range. --192.28.65.210 (talk) 10:18, 18 August 2010 (UTC)
 * I wonder if there were supplemental markings to identify wich plant made a particular part? But it makes sense that there was only one "manufacturer". Is that still the case today? When I've got my high speed connection again I will have to look at some of those sites; perhaps Google Translate migh tgive a sense of what's there. --Wtshymanski (talk) 13:10, 18 August 2010 (UTC)
 * AFAIK the update to the state standard introduced such markings as a suffix after the functional code. the old standard "ОСТ 11.073.915-80 Микросхемы интегральные. Классификация и система условных обозначений" sets the four-part model code, and being from soviet times does not have manifacturer identification. even if there were some markings allowing to distinguish which fab was making the ICs I am not aware of them.
 * the updated ОСТ 11.073.915-2000 specifies manifacturer suffix codes. you could have a look at this remark, this is the only online source I can find.
 * unfortunately the russian standartisation agency still does not publish the standarts online, and I do not have the full list of manifacturers codes. you could read more (via translator) on ru:ГОСТ. --192.28.65.210 (talk) 18:43, 23 August 2010 (UTC)

Yet Another Slow-Motion Edit War
Yet Another Slow-Motion Edit War: The recent editing history at 7400 series shows that some of the editors here are currently engaged in an edit war.

Being involved in an edit war can result in you being blocked from editing.

Undoing another editor's work—whether in whole or in part, whether involving the same or different material each time—counts as a revert. Also keep in mind that while violating the three-revert rule, which states that an editor must not perform more than three reverts on a single page within a 24-hour period, often leads to a block, you can still be blocked for edit warring&mdash;even if you don't violate the three-revert rule.

To avoid being blocked, instead of reverting please consider using thuis article's talk page to work toward making a version that represents consensus among editors. See BRD for how this is done. --Guy Macon (talk) 19:22, 27 April 2013 (UTC)

7400 LS and F Series: Lack of History and Wrong Information
Does someone know when the LS series came out? Preferably with a source? It is inexcusable that a historical article doesn't at least list the YEAR for everything.

Also, this article has wrong information in it. Here's one example, "74F – Fast, Fairchild's version of TI's 74AS. 3.4nS, 6 mW, 4.5–5.5V. Introduced in 1985." I don't presume to know when it came out, but I am sitting here looking at an F 74F157 PC with a date code of 8027 and I don't think time travel will explain it. I have boards full of these with 1980-83 date codes, so 1985 is just nonsense.76.254.18.119 (talk) 03:15, 9 December 2013 (UTC)


 * Thank you for identifying the error. It is sharp-eyed users like you who are our first line of defense against errors.
 * I found a source for the history of Fairchild: http://www.fairchildsemi.com/about-fairchild/history/
 * It lists FAST as being introduced in 1978. Looks like someone confused FAST with FACT, which was introduced in 1985.
 * I changed FAST from 1865 to 1978 and removed the 1985 date from ALS and AS. Obviously, if FAST was Fairchild's version of TI's AS, AS wasn't introduced in 1985.
 * Again thanks for catching the error. --Guy Macon (talk) 06:31, 9 December 2013 (UTC)

Need help finding citation for NAND gate in analog mode
Regarding this edit, I was trying to find a citation to support the statement in the article. I found a non-RS source: Note the second file the author references, which look like a page from the source I am looking for. Can anyone find the original source for this? It's one of those "this is interesting and it does work, but I wouldn't do that in any actual product" ideas that has been around forever. --Guy Macon (talk) 01:39, 18 March 2018 (UTC)
 * Hmm, is close, but that's for the CMOS flavor.  -- RoySmith (talk) 01:58, 18 March 2018 (UTC)
 * My personal experience (which is useless as a source, see WP:OR) from years ago includes running tests on 7400, 74LS, 74C, 74HC, etc. to see which ones could amplify. I distinctly remember not being able to get HC to work. I keep thinking that if I spoke German I would be able to find it in something written by Dieter Nührmann (Note the "ü" in the name). Alas, if we can't find a source I think we have to delete the claim. Posting a link at Wikipedia talk:WikiProject Electronics. --Guy Macon (talk) 02:15, 18 March 2018 (UTC)
 * Did you find anything more regarding your comment at Talk:7400 series? --Guy Macon (talk) 02:22, 18 March 2018 (UTC)


 * I remember this being a common thing amongst home builders for RF amplifier applications. The cheapness of the chips and their high frequency cabability was what drove it, plus the kudos of doing something surprising.  Old enthusiast magazines are the place to look. I'm seeing a few possible sources on gbooks, but they only have snippet view;
 * Two-stage linear amplifer, Amateur Radio
 * "We might be tempted to bias a TTL inverter or gate into its active region and try to use it as a linear amplifier", TTL Cookbook
 * WP:LIBRARY can help get you copies of any usable article. As for Nührmann, he has written a lot of books and your link is not clear on which one it is. I would try Der Hobby-Elektroniker prüft seine Schaltungen selbst first, but that's just a guess. There was no preview on any of his titles I tried in gbooks. SpinningSpark 09:01, 18 March 2018 (UTC)

I think part of what made this popular was that TTL gates came in units of 4 or 6, so you often had a few unused gates left over in a project. If you needed an amplifier, it was tempting to try to repurpose what was already on the board. -- RoySmith (talk) 16:41, 18 March 2018 (UTC)
 * I think "might be tempted" is the operative phrase. It's hard to make a decent stable amplifier this way.  But it might be OK if tuned up for amplifying a narrow frequency range, more or less as an oscillator. Dicklyon (talk) 03:43, 9 April 2018 (UTC)

Merge with List of 7400 series integrated circuits
Hi , No objection to moving the article to a more descriptive name, but I would not combine this article with List of 7400 series integrated circuits since that list is rather large and often not of interest for readers looking for an overview of the 7400 series. Drahtlos (talk) 16:06, 13 July 2018 (UTC)
 * I agree with Drahtlos. The title change is fine, but I wouldn't do the merge.  -- RoySmith (talk) 16:08, 13 July 2018 (UTC)

and, thank you for the ping. I better linked the pages, following your advice.-- Rings48 16:21, 13 July 2018 (UTC)

What is the subject of this article?
Is this article about (bipolar) TTL ICs with the 7400 part number sequence, or about logic chips in general? There were no "surface mount" bipolar chips, unless you want to count a flat pack as a surface mount chip. Lord knows, in the encyclopedia that things a hybrid integrated circuit is a discrete transistor, anything goes. --Wtshymanski (talk) 23:03, 20 July 2019 (UTC)


 * You have asked a question containing a False dilemma. I can create a false dilemma question too: "Are our TO-3, TO-5 and TO-92 articles about bipolar transistors with the TO package designation, or about semiconductors in general?" In my misleading question if I answer one way TO-93 JFETS are excluded, and if I answer the other way diodes are included. Likewise, if I answer your misleading question one way 74HC is excluded and if I answer the other way 4000 series CMOS is included.


 * The answer is in the article. This article is about the original family of TTL logic chips that are prefixed with 74 or 54 in the part number and it is about the subsequent generations of pin-compatible descendants of the original family.


 * Here is a surface mount 7400/7400LS-series logic gate: [ https://www.mouser.com/ProductDetail/Texas-Instruments/SN7400D?qs=sGAEpiMZZMtMa9lbYwD6ZJeO7ZVi7W4d9IMhLD9QPZ8%3D ]. That page has a link to the datasheet and package dimensions. The datasheet says "Package Options Include: Plastic Small-Outline, Shrink Small-Outline". You do agree that Small Outline Integrated Circuits are surface mount, right? The TI datasheet says you can get it in standard DIP as well as SOP. Does picking the SOP make it no longer a 7400-series part? --Guy Macon (talk) 02:00, 21 July 2019 (UTC)


 * wut? This article isn't ONLY about the original 1960s 7400 TTL family, though the intro does need clarification.  •  Sbmeirow  •  Talk  • 02:29, 22 July 2019 (UTC)


 * I fixed it. The article mislead me by talking about "TTL" in the lead. Clearly we must expand the subject greatly. --Wtshymanski (talk) 23:02, 22 July 2019 (UTC)


 * Your edit was fine, and reduced the possibility of confusion by a reader who doesn't bother reading the third paragraph ("Today, surface-mounted CMOS versions of the 7400 series are used in various applications in electronics and for glue logic in computers and industrial electronics").
 * Your edit summary, however, was factually incorrect, and I hope that you are not planning on defending your error or editing the page to support your error, as you did at Talk:Power factor/Archive 2
 * You wrote in your edit summary "so, not about TTL - remove confusing limitation because it's really about any chip that has a "7" and a "4" in its part number." That is incorrect. An AD8047 op-amp is not part of the 7400 family, and neither is a 4071 CMOS Quad 2-input OR gate. A 40174 CMOS Hex D-type flip-flop is not part of the 7400 Family, and neither is a Dumont Laboratories Model 74-93 Oscilloscope.
 * Says who? what's the legal definition of a "7400 family" ? --Wtshymanski (talk) 20:38, 23 July 2019 (UTC)
 * Nope. Not taking the bait. You have demonstrated in the past a cult-like rejection of any argument, no matter how good, and any reference, no matter how authoritative, that disagrees with your WP:FRINGE views on electronics.
 * One great example of this behavior is your ongoing insistence that Power Factor can only be positive. You are wrong, you refuse to admit it, and all of the words dozens of Wikipedia editors have written in response to your nonscientific beliefs have been a colossal waste of time.
 * When you started pushing the fringe view that power factor is always positive, you were corrected by none other than Wikipedia user AMcEachern (real name Alex McEachern). Alex McEachern is an IEEE Fellow (awarded for "contributions to power quality measurement"), and is co-author of IEEE 519, IEEE 1159, SEMI F47, IEC 61000-4-30, IEC 61000-4-34, IEC 61000-4-11 and, most notably, co-author of IEEE 1459, which you keep citing as supporting your fringe view. The interested reader can see the whole discussion at Talk:Power factor/Archive 2. Alex McEachern's comments to you are at Talk:Power factor/Archive 2. I believe that your editing record makes it clear that you are a disruptive editor who is 100% convinced that you are always right, 100% convinced that everybody who has ever disagreed with you is always wrong, and that no argument or evidence will ever cause you to change your mind.
 * I would also once again bring to your attention this document which contains the words "I am  grateful  to  two  contributors to the Wikipedia.org article on Power Factor, W.T. Shymanski and Guy Macon, for their  interesting  and  useful  written  discussion  there,  which triggered  my  preparation  of  this  paper." If that does not convince you, nothing will. --Guy Macon (talk) 00:00, 24 July 2019 (UTC)
 * A discussion of the power factor article is off-topic here. I asked "What is this article about?". If it was titled "SSI logic parts", the gra-bag TAB books approach to listing our favorite parts would be consistent with that topic.  But the notion that some nightmarish surface-mount 1.8 volt CMOS single-gate part is in a "family" with the good-old SN7400 is peculiar to Wikipedia. --Wtshymanski (talk) 01:57, 24 July 2019 (UTC)
 * You exhibit the exact same behavior on dozens of Wikipedia articles, then you show up at another Wikipedia article and engage in the exact same behavior, and you think that mentioning your pattern of behavior is off-topic? How convenient for you. Nonetheless, if you don't want your behavior to be mentioned, I will be happy to stop mentioning it. Those who are interested can see the pattern from the one example I gave, or could email me for a dozen other examples. --Guy Macon (talk) 03:19, 24 July 2019 (UTC)
 * You seem to be stuck on the idea that the 7400 series is either limited to the original through-hole TTL chips or that we pretty much have to include anything with a 74 in the part number.
 * I have already told you that this article is about the original family of TTL logic chips that are prefixed with 74 or 54 in the part number and it is about the subsequent generations of pin-compatible descendants of the original family in various packages. Please stop pretending that this has not been explained to you. --Guy Macon (talk) 02:05, 23 July 2019 (UTC)
 * We left out an important member of the family, the 741 - it must be important, it has the lowest number. "Pin compatible" with what - many of the devices we list in this eclectic article have no pin-compatible counterparts in the Texas Instrument TTL Logic Data Book, 1988 edition. It's not a "series" of chips, it's a coincidence in part numbers.  WP has committed an original syn here. --Wtshymanski (talk) 20:38, 23 July 2019 (UTC)
 * Again, not taking the bait, and I advise others to also ignore you. [ https://wondermark.com/1k62/ ] --Guy Macon (talk) 00:00, 24 July 2019 (UTC)
 * Is a 54LS13 a member of the 7400 family? --Wtshymanski (talk) 20:40, 23 July 2019 (UTC)
 * Yes, if it's a Dual 4-input NAND gate Schmitt trigger, same as a 7413. Dicklyon (talk) 22:09, 23 July 2019 (UTC)
 * How about an 8288 divide by 12 counter? Is it a member of the 7400 family, too? Can we explain to J. Random Reader who gets to be part of the family and who doesn't, or is this just something we cognoscenti must never share with the great unwashed masses? --Wtshymanski (talk) 01:24, 24 July 2019 (UTC)
 * I have no idea what that is. Why would you think it might be in the 7400 family?  Not sure what you're asking about the masses, washed or otherwise.  Not sure what you think the problem is here; just that the family boundary might not be crisp? Dicklyon (talk) 02:34, 24 July 2019 (UTC)
 * The 8288 is listed on page 7 (according to the page numbers on the pages - it is page 23 of the PDF) of the 1971 National Semiconductor Corporation Digital Integrated Circuits catalog. So I would say, "Hey great unwashed masses! Here is a reliable source from 1971 that specifically says 'Series 54/74 technology' and 'Series 54/74 compatible'! Here on Wikipedia we rely on citations to sources to answer such questions. See WP:V and WP:RS."
 * Good find. I had forgotten that National had extended the family with their own DM72XX/DM82XX numbers. Dicklyon (talk) 04:00, 24 July 2019 (UTC)
 * Also there is this. --Guy Macon (talk) 03:32, 24 July 2019 (UTC)
 * So the only way to tell if something is part of the (Wikipedia-defined) "7400 family" is put it up on this article and see if it passes the editorial board? Could we put a pin in this and rename the article something more practical like "Small scale integrated circuit logic", since the "TTL" part has long been abandoned and evidently something can be a "7400 family" member even if it doesn't ahve "74" anywhere in its part number. The idea of "family" is so vague as to be useless.  --Wtshymanski (talk) 05:05, 3 August 2019 (UTC)
 * [ https://wondermark.com/1k62/ ] --Guy Macon (talk) 05:28, 3 August 2019 (UTC)

Historical stuff isn't as clear cut as simple math rules (1+1=2), but the concept of logic families and series has been around for decades, so knock off the sillyness. 05:55, 3 August 2019 (UTC) — Preceding unsigned comment added by Sbmeirow (talk • contribs) 05:56, 3 August 2019 (UTC)
 * https://www.nutsvolts.com/magazine/article/understanding_digital_logic_ics_part_2
 * https://www.computerhistory.org/siliconengine/standard-logic-ic-families-introduced/
 * https://archive.org/details/bitsavers_tidataBookVol1_11973959/page/n17 (1984 databook)


 * "Reasoning will never make a man correct an ill opinion, which by reasoning he never acquired: for, in the course of things, men always grow vicious, before they become unbelievers..." --Jonathan Swift ( 1721)
 * In modern language that would be
 * "You cannot reason people out of something they were not reasoned into. They will viciously attack you instead of abandoning their beliefs".
 * --Guy Macon (talk) 13:10, 3 August 2019 (UTC)

Revised lead
I took a stab at overhauling the intro section. It might need some elegant wordsmithing help. • Sbmeirow  •  Talk  • 11:23, 23 July 2019 (UTC)


 * I think the latest edits to the lead are very much an improvement. Good job! --Guy Macon (talk) 12:46, 23 July 2019 (UTC)


 * Thanks. Others are welcome to improve or expand it. • Sbmeirow  •  Talk  • 13:50, 24 July 2019 (UTC)

I have an problem with the following paragraph:


 * While designed as a family of digital logic, some TTL chips were used in analogue circuits, such as Schmitt triggers. Like the 4000 series, the newer CMOS versions of the 7400 series are also usable as analogue amplifiers using negative feedback (similar to operational amplifiers with only an inverting input). However, this type of circuit suffers from significant harmonic distortion and shortened component life.  As the parts are not designed to operate in the partially on/off region except when switching states, heat buildup can be severe.

I was unable to find any source for using logic chips as analog amplifiers, although I have heard of it and did some experiments with it years ago (nothing that went into production, just fooling around in the lab). See Talk:7400-series integrated circuits.

Also an op-amp based Schmitt trigger is really more of an example of using an analog chip to do a digital function than it is an example of using a digital chip to do an analog function

Didn't some early personal computers use logic outputs to drive speakers? If we can find sources that might be a better example of using digital to do the job of analog. --Guy Macon (talk) 12:46, 23 July 2019 (UTC)
 * Don Lancaster in "TTL Cookbook" says on pp. 169-170 that while you could theoretically bias a gate into the linear region, you'd rather not rely on it. He does give an example of a ring oscillator made of open collector gate. TTL crystal oscillators were present in some personal computers; I have schematics for the obscure Ibex 7150 and the rather more popular Osborne 1, and both of them use crystal oscillators made of a TTL gate. (The Osborne had bipolar transistors to drive the non-TTL-compatable clock input of the Z80, the Ibex worked OK at 2.5 MHZ driving the Z80 clock from the TTL oscillator but to work reliably at 4 MHZ the 7406 had to be changed to the HCMOS "pin compatible" equivalent).   Don't know what a Kaypro used.  The IBM XT used a real dedicated clock generator chip. --Wtshymanski (talk) 23:32, 23 July 2019 (UTC)
 * And here is another that says no to driving a speaker with TTL. Not that someone else might not have done it anyway... Dicklyon (talk) 00:21, 24 July 2019 (UTC)


 * This guy says "Combining L-C tuned circuit with TTL inverter gives low-cost bandpass amplifier for use as frequency multiplier, or i-f amplifier. Q of feedback path can be modified ..." Dicklyon (talk) 00:27, 24 July 2019 (UTC)
 * And here's one showing a Schmidt trigger (and other stuff) made with TTL NAND gates. Not really a good idea, but it can work. Dicklyon (talk) 00:30, 24 July 2019 (UTC)


 * I have no problem with mentioning the analog uses, but it should be moved out of the lede, and buried somewhere far down in the article. It was a quirky oddity, which shouldn't be given top billing.  -- RoySmith (talk) 15:01, 3 August 2019 (UTC)
 * I should also note that I added "citation needed" tags to this section a while back, and nobody's found citations for this yet. Maybe, if nobody can come up with good citations, we should just drop it completely.  -- RoySmith (talk) 15:03, 3 August 2019 (UTC)
 * I say nuke it. Despite the fact that I actually did this in the lab (unbuffered 4000-series CMOS maybe kind of work if the phase of the moon is right, 7400-series H and HC don't work at all) the sources simply do not show that this was ever a significant use. --Guy Macon (talk) 22:34, 7 September 2019 (UTC)

Speed
The speeds given seem unreferenced and some technologies missing. See http://www.ti.com/lit/sg/sdyu001ab/sdyu001ab.pdf --Kitchen Knife (talk) 14:09, 4 September 2019 (UTC)
 * and this Also by TI some different abbreviations http://digsys.upc.es/csd/units/Elect/TI_Digital_Logic_Families.pdf --Kitchen Knife (talk) 20:16, 7 September 2019 (UTC)

HCS
Is this a fa,ily that needs adding https://www.ti.com/lit/an/scea069a/scea069a.pdf --Kitchen Knife (talk) 21:38, 25 June 2022 (UTC)
 * This parts list is friend to all integrated circuits. As long as it has a "7" or a "4" somewhere in its part number and is some kind of digital IC, you'll not find anyone denying it a home here. Parts lists articles are best when they have lots of parts in them, after all. The more the merrier. --Wtshymanski (talk) 02:26, 7 July 2022 (UTC)
 * This isn't the parts list. Its the description of what 7400 is and the technology in which it is implemented and the HCS technology is not mentioned. --Kitchen Knife (talk) 09:07, 7 July 2022 (UTC)
 * This article is also a kitchen sink...who am I to complain about a few more potato peels in the sink? --Wtshymanski (talk) 00:36, 8 July 2022 (UTC)

8400?
While trying to find a WP:RS for the 6400 series, I found https://hackaday.com/2021/12/06/ttl-and-cmos-logic-ics-the-building-blocks-of-a-revolution/, which also mentions an 8400 series, which I'd never heard of before. Don't know any more about it than what I can read on that page, so just mentioning it here to get it recorded somewhere. -- RoySmith (talk) 02:22, 5 March 2023 (UTC)

In a book I have, I found a number of manufacturers for the 6400 and 8400 series. Several other books (e.g. this one) mention the 6400 series for CEMI. Unfortunately, I have found actual manufacturer's data sheets for these series only for Tesla. A 1973 data book from Siemens mentions the 8400 series as equivalent to their FLH xx5 series. From that I would conclude that a company other than Siemens had introduced an 8400 series that was reasonably well known in 1973. Siemens printed the 7400 / 8400 number on their ICs in addition to their own FLH designations (e.g. ). Drahtlos (talk) 01:13, 8 March 2023 (UTC)
 * 6400: Texas Instruments, Transitron, Ferranti, ITT
 * 8400: Telefunken, Tesla
 * Another data point: A 1970 data sheet from Mullard mentions the 6400 series as equivalent to their FJH xx6 series. Drahtlos (talk) 14:52, 8 March 2023 (UTC)
 * The 6400 series is still alive at Texas Instruments (and has been again since 1989). Drahtlos (talk) 18:44, 6 June 2023 (UTC)

Family 74FC ?
The family table lists a 74FC family but I can find no reference for it (only the 74FCT family appears to have been manufactured). For the time being I am removing 74FC. Whoever finds a reference, can add it back. Drahtlos (talk) 23:09, 23 March 2023 (UTC)

Those are not logic circuits per se
Hello anonymous editor, the 7400 series includes many IC that are not simple logic IC but counters, ALUs, or drivers. Why would you exclude an SN64BCT125? What about a 74LS125? Or would you exclude the entire 74BCT series? Drahtlos (talk) 20:44, 8 October 2023 (UTC)