Talk:7400 series

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[edit] Advertisement

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)

[edit] 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)

[edit] 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)

[edit] Minicomputers Using 7400 series TTL

The 74181 was the 'workhorse' of the minicomputer era. It was the function generator for machines like the:

[edit] History

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 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)

[edit] 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)

[edit] 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)

[edit] 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)

[edit] 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)


[edit] 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)

[edit] 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)

[edit] 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 [1]. -- RoySmith (talk) 20:57, 14 January 2008 (UTC)

[edit] Sources for references...

Find sources: 7400 series — news, books, scholar -- RoySmith (talk) 21:00, 14 January 2008 (UTC)

[edit] 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)