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Old 8th Apr 2021, 3:19 am   #1
100grand
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Default National Semiconductor IC batch codes

Does anybody know how to read the batch codes or manufacturing codes on old NS integrated circuits? For instance, I have a DM7400N with a '007' on it and another one with a '037P' and another with '-827 B+'. They seem to be all over the map. Just wondering if anyone knows how to read those. Thanks.
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Old 8th Apr 2021, 12:50 pm   #2
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Default Re: National Semiconductor IC batch codes

Don't know if this helps: from a 1995 databook
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Old 8th Apr 2021, 1:43 pm   #3
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Default Re: National Semiconductor IC batch codes

Something does not look quite right with the font, and the date code should normally consist of four digits together with a character or two. Picture attached of a genuine Nat-Semi DM74x which was manufactured in 1985 week 52.

Edit: matches format as shown in previous post.

As an afterthought, does the ink come off easily?

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Old 8th Apr 2021, 8:42 pm   #4
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Default Re: National Semiconductor IC batch codes

I just checked on my MK14 and the date codes are /831 on the DM74S571Ns, /845 on the INS8060N, /847 on INS8154N, /821 on DM7445N, 7845 on DM74LS178N, 839 on DM74LS157J, -833 on DM80L95N, -816 on DM7408N, -831 on DM74LS04N, -841 on DM74LS00N, -840 on DM74LS08N.

I think the variation will be from different manufacturing sources not always following the letter of the spec.
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Old 8th Apr 2021, 8:45 pm   #5
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Default Re: National Semiconductor IC batch codes

Quote:
Originally Posted by Marconi_MPT4 View Post
does the ink come off easily?
Yes, with a file
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Old 9th Apr 2021, 12:35 am   #6
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Default Re: National Semiconductor IC batch code.

Quote:
Originally Posted by Julesomega View Post
Don't know if this helps: from a 1995 databook
Terrific! Thank you! Though it would seem to be a different schema than the older ones like I have.

Quote:
Originally Posted by Marconi_MPT4 View Post
Something does not look quite right with the font, and the date code should normally consist of four digits together with a character or two. Picture attached of a genuine Nat-Semi DM74x which was manufactured in 1985 week 52.

Edit: matches format as shown in previous post.

As an afterthought, does the ink come off easily?

Rich
What you're saying makes absolute sense. Which is why I was confused by the codes I have. Maybe it's because the ones I have are probably much older. I think they are from the mid to late 70's. Perhaps the info was coded much differently then. The ink is on there pretty good. Doesn't scratch off easy. Thanks for the reply!

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Quote:
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does the ink come off easily?
Yes, with a file


Quote:
Originally Posted by Mark1960 View Post
I just checked on my MK14 and the date codes are /831 on the DM74S571Ns, /845 on the INS8060N, /847 on INS8154N, /821 on DM7445N, 7845 on DM74LS178N, 839 on DM74LS157J, -833 on DM80L95N, -816 on DM7408N, -831 on DM74LS04N, -841 on DM74LS00N, -840 on DM74LS08N.

I think the variation will be from different manufacturing sources not always following the letter of the spec.
certainly sounds plausible. Thanks.
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Old 13th Apr 2021, 1:40 am   #7
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Default Re: National Semiconductor IC batch codes

Quote:
Originally Posted by Mark1960 View Post
I just checked on my MK14 and the date codes are /831 on the DM74S571Ns, /845 on the INS8060N, /847 on INS8154N, /821 on DM7445N, 7845 on DM74LS178N, 839 on DM74LS157J, -833 on DM80L95N, -816 on DM7408N, -831 on DM74LS04N, -841 on DM74LS00N, -840 on DM74LS08N.

I think the variation will be from different manufacturing sources not always following the letter of the spec.
Those all seem to have been manufactured in 1978 (the code format likely being YWW). Does that match the MK14 production period?
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Old 13th Apr 2021, 1:42 am   #8
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Default Re: National Semiconductor IC batch codes

Quote:
Originally Posted by 100grand View Post
Does anybody know how to read the batch codes or manufacturing codes on old NS integrated circuits? For instance, I have a DM7400N with a '007' on it and another one with a '037P' and another with '-827 B+'. They seem to be all over the map. Just wondering if anyone knows how to read those. Thanks.
Likely 1980 week 7 (or maybe it has a license to kill), 1980 week 37 and 1978 week 27, respectively. I think the logo and the font would confirm that era.
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Old 13th Apr 2021, 2:15 am   #9
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Default Re: National Semiconductor IC batch codes

Is it ink, or has it been writen by laser?
Is there anything written on the underside.

David
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Old 13th Apr 2021, 4:38 am   #10
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Default Re: National Semiconductor IC batch codes

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(or maybe it has a license to kill)
LOL!

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Likely 1980 week 7 (or maybe it has a license to kill), 1980 week 37 and 1978 week 27, respectively. I think the logo and the font would confirm that era.
Thank you. That makes total sense. Except I've seen a board I know was built in 1978 which has the same NS IC's (same logo and font) with code 027P. That would mean 1980 week 27, right? Except that's after it was put on the board. Something isn't adding up. Maybe I've finally found the glitch that proves our universe is a simulation. Thanks Maarten.
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Old 13th Apr 2021, 3:26 pm   #11
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Default Re: National Semiconductor IC batch codes

Quote:
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Those all seem to have been manufactured in 1978 (the code format likely being YWW). Does that match the MK14 production period?
Yes, my MK14 is an issue IV from end of 78 or sometime early in 79. I think there was also an issue V, though not sure when that was introduced and I donít think there were so many of those.
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Old 13th Apr 2021, 4:26 pm   #12
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Default Re: National Semiconductor IC batch codes

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Those all seem to have been manufactured in 1978 (the code format likely being YWW)
Maybe it's WWY? Although there aren't 82 weeks in a year so that's not right either. Bother.
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Old 13th Apr 2021, 7:41 pm   #13
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Default Re: National Semiconductor IC batch codes

The only use of WWY I'm aware of, are Philips date codes on assemblies and equipment, up to the mid to late 1960's.

Philips later did use non-existing week numbers to indicate months and quarters, but I don't think anyone else did that either.

I'd guess the 027 date code could be an IC that was replaced later on.
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Old 13th Apr 2021, 10:34 pm   #14
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Default Re: National Semiconductor IC batch codes

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I'd guess the 027 date code could be an IC that was replaced later on.
I would've thought the same, but this is where it gets interesting. That board was built for a prop in a movie which was released in the spring of 1980. After which, the board was never used again. To make it more certain it wasn't simply replaced, there was a duplicate backup board which was never used and it has the exact same IC on it with the same 027P.
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Old 14th Apr 2021, 5:26 am   #15
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Default Re: National Semiconductor IC batch codes

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I'd guess the 027 date code could be an IC that was replaced later on.
Actually, the more I look into this by looking at other IC's on ebay, the more I think you must be right. It's YWW and that IC was replaced. Very interesting. Thank you.
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Old 15th Apr 2021, 12:21 am   #16
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Default Re: National Semiconductor IC batch codes

Your post #14 would have had me doubting it as well. Could have been something external that blew up this IC during usage as a prop? Then it would of course make sense that the IC on the spare board was also blown as the first action after a malfunction would have been to try the spare board.
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Old 15th Apr 2021, 5:46 am   #17
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Default Re: National Semiconductor IC batch codes

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Your post #14 would have had me doubting it as well. Could have been something external that blew up this IC during usage as a prop? Then it would of course make sense that the IC on the spare board was also blown as the first action after a malfunction would have been to try the spare board.
Very good point. Something must've happened to it, despite being used in only one shot. Thank you for helping me to figure this out. I don't think anyone knew this part of the story of this prop/costume piece before. A small but interesting detail. Thanks.
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