74XX Series: Alternative Numbering? - Page 1
Forum section: electronics / beginners

author: 1-ev
author_rank: Newbie
timestamp: December 23, 2014, 08:51:17 pm
content: Dear all,i've got a whole bunch of supposedly 74-series IC's. However, i'm not able to identify all of them, because of their numbering...for example:239 2100 (Texas Instruments) - should be 7400158 2607 - should be 74LS174159 0171 - ?239 2106 - ?239 2108 - ?...I did a quick internet search, but i couldn't find any information. Does somebody know this numbering system?Regards,1-ev

author: IconicPCB
author_rank: Super Contributor
timestamp: December 23, 2014, 09:06:05 pm
content: Search the web for Hewlett Packard part number cross refference. Those codes look very much like old HP stock.

author: 1-ev
author_rank: Newbie
timestamp: December 23, 2014, 09:15:24 pm
content: Quote from: wilfred on December 23, 2014, 09:00:11 pmThey came along with a "Mini-Micro Designer I" i've purchased...some of them are manually labeled with their corresponding 74-number.

author: mrgregs
author_rank: Contributor
timestamp: December 24, 2014, 12:20:43 am
content: I found this copy of the Mini Micro Designer I manual which has the original parts marked (and schematics) in a google search - maybe that could help?http://www.joelowens.org/mmd1/manual_revl.pdf

author: macboy
author_rank: Super Contributor
timestamp: December 24, 2014, 12:26:59 am
content: They are not HP part numbers; they are always 4+4 digits in my experience.I foundthis schematicfor some kind of IBM keyboard controller that describes the part in your photo, but shows National as the manufacturer, not TI. Maybe they are IBM in-house part numbers?

author: JoeO
author_rank: Frequent Contributor
timestamp: December 24, 2014, 02:47:37 am
content: Yes, they are IBM part numbers. I do remember that 2392100 is a 7400.However there is not a correlation, i.e. 2392104 is not a 7404.

author: Richard Crowley
author_rank: Super Contributor
timestamp: December 24, 2014, 03:04:58 am
content: They are proprietary OEM "house numbers". Manufacturers use them internally for inventory control, etc.And sometimes, they are used for obfuscation, to prevent others from knowing exactly what components they are.First, you must identify what manufacturer's numbers those are.Then maybe you can find a secret decoder ring to translate them into standard numbers.But I wouldn't hold my breath. Especially if you can't even identify the manufacturer.

author: Richard Crowley
author_rank: Super Contributor
timestamp: December 24, 2014, 03:08:36 am
content: IF those ARE chips from IBM, then it doesn't agree with your assumption: 239 2100 = 7400At least not according to this list:http://www.kbdbabel.org/kbdbabel-ibm-part-number-list

author: amyk
author_rank: Super Contributor
timestamp: December 24, 2014, 05:31:07 am
content: 7437 and 7400 have the identical logic function and pinout, the difference is the '37 can supply more current.Looks like you would find one of these very useful:https://www.eevblog.com/forum/testgear/chinese-ic-testers/

author: 1-ev
author_rank: Newbie
timestamp: December 24, 2014, 09:11:23 am
content: Quote from: macboy on December 24, 2014, 12:26:59 amThank you...the IC numbering shown there fits to the few hand labeled ones i've got (except for 239 2100, which should be 7400 and not 7437). As it looks, it will be hard to identify the remaining IC's...Thank you all for your help...Merry Christmas,1-ev