Identification of old Integrated circuits - Page 1
Forum section: electronics / projects

author: elecncs
author_rank: Newbie
timestamp: February 08, 2018, 10:52:12 pm
content: I am a teacher sponsoring an electronics club through my school. I am looking for some help determining what I have received through some donations from a widow whose husband was an ex-military radio and telecommunications officer and left a lovely stash of things for us to use (A few examples attached).When searching for the numbers on some of these parts (specifically the ti 7806 components) I found data sheets for voltage regulators but not in the form factor depicted. searching each set of the other set of numbers did not help me much either.I would love to be told how I could find these datasheets on my own and or any troubleshooting in my method of trying to find these sheets or if anything other than pure experimentation would help me to determine what these are. I am very much hoping to find some additional projects in which I can use these, but am concerned they may require more than my current knowledge or they are so old the datasheets are just unavailable.I have about 3 dozen cases labelled MOSTEK that are ~10 inches by ~4 inches with such old anti-static foam that it crumbles as I try to remove some of the chips. with usually at least one row of chips or more each.If this would be better placed on the vintage computing board please let me know and it seemed more appropriate here.

author: helius
author_rank: Super Contributor
timestamp: February 08, 2018, 11:04:09 pm
content: The white chips in the first picture are resistor networks, used for bus termination. The chips in the second picture are TI 74H11 triple AND gates. They all have Burroughs custom part numbers—Burroughs was one of the manufacturers of mainframe computers, like IBM.

author: elecncs
author_rank: Newbie
timestamp: February 08, 2018, 11:39:01 pm
content: First, thank you so much for replying.So deconstructing your methodology I assume on the TI chips that the SN stands for Serial Number and then it is followed by the component ID which would explain why I wasn't getting any / the correct hits searching the strings.I can then use the number on the left which, I assume, is the Burroughs number to cross reference it to the other chips of that type? For chips where I only have that burroughs number is there a datasheet source I could feed that into to tell what it is?What do the 7806 or 7810 at the top of these chips mean?Some of the chips rather than a J at the end have a BJ and a CSN instead of an SN would it be safe to ignore these letters as you did the J in my searches?This is super exciting I have never been trained on logic gates, but look forward to learning the ropes with my students

author: danadak
author_rank: Super Contributor
timestamp: February 08, 2018, 11:57:15 pm
content: The logo on some of the chips is National SemiconductorYou can find a lot of old scanned databooks at wwww.archive.orgLot of old parts floating around, Signetics, Fairchild, Motorola, Xicor......https://steveblank.files.wordpress.com/2010/08/fairchild-silicon-valley-genealogy.jpghttps://en.wikipedia.org/wiki/Silicon_Valley#Notable_companiesRegards, Dana.

author: floobydust
author_rank: Super Contributor
timestamp: February 09, 2018, 12:00:15 am
content: I am speaking very generally, but most IC numbers can be broken down. Most of us here can look at an IC and ID it right away, it's just years of knowing them.First I look for a logo (NS=National Semiconductor) or manufacturer's name (Beckman).Four digit date code (year, week) i.e. 7810 is 1978, 10th week. Less encountered is three digits, i.e. 806 = 1978, 6th week.Then the root part number. Usually there is a prefix and a number and then a suffix.'SN' (TTL logic originally by Texas Instruments but many second-source them)'74nxx' logic gate part number- middle letter n if present identifies the logic family, i.e. LS is low power Schottky, H high speed.Suffix is usually adding a package code (N=DIP) and a temperature range.So for SN74H11J, it is TTL logic, H= high speed, 7411 is the root logic, and J is ceramic DIP package with military temperature spec. ?55°C to 125°C.Your pics also have rarer "house" numbers 1447-3557 where some product manufacturers got their in-house part number on the IC. I think that is a Burrough's house part number.

author: helius
author_rank: Super Contributor
timestamp: February 09, 2018, 12:13:14 am
content: "SN" is a prefix code that identifies the manufacturer of the chip. It is used by Texas Instruments. Other prefix codes identify other manufacturers.74 is the name of the series of TTL MSI circuits that Texas Instruments began producing in 1964:https://en.wikipedia.org/wiki/7400_series"H" is the generation of transistor technology within the 74 series.https://en.wikipedia.org/wiki/Transistor–transistor_logic#Sub-typesThe code that identifies the part within the 74 series is 7411 or 74_H_11 for the particular generation of transistor. A SN7411 is a triple, 3-input AND gate, which means that there are three separate AND gates, each having 3 inputs. The gates share a common power supply (VCC) and ground.You can look up the different parts in lists like this:https://en.wikipedia.org/wiki/List_of_7400_series_integrated_circuitsThe part number suffix letters identify the packaging. J refers to a ceramic DIP package; N would be a plastic DIP.If the package letter is preceded by an A, B, or C, they refer to speed grades. After chips are fabricated on silicon wafers, they are tested and segregated into different "bins" based on their speed: the speed is marked on the package as A, B, or C, or as a number in nanoseconds or megahertz for memories or processors, respectively.7806 or 7810 are date codes. "Jellybean" (cheap) chips like these do not normally have serial numbers. Instead they carry date and factory codes. The first two digits (or first digit for the National Semiconductor parts: 806 and 808) identify the year and the last two digits are for the week during that year. So 7806 means the 6th week of 1978, around February 8 1978. So it makes sense that all the chips in that box were sold at around the same time, whether from Texas Instruments or from National. The National parts do not have an industry standard part number at all, but only the Burroughs custom number, but since it is the same, you can be sure they are DM74H11J (the equivalent National part number to TI's SN74H11J) as well.It helps to have a cross-reference table to identify custom-numbered parts. You can get one for Burroughs athttp://www.bitsavers.org/pdf/burroughs/icData/burroughs_IC_crossref.pdf

author: Rich M
author_rank: Newbie
timestamp: February 23, 2022, 03:52:07 am
content: I know this is an old thread but it seems like you guys can help me ID some old IC's I have. They are 16-pin CERDIP. I was given them in the early 80s'.My guess would be a 9314 quad latch but not sure with all the other markings (I assume the 75 refers to 1975 as the year of manufacture).

author: gman76
author_rank: Contributor
timestamp: March 15, 2022, 05:11:37 am
content: AFAIK MOSTEK made DRAMs, maybe other types of memory too, like SRAMs and PROM/EPROMs.