Wondering what this 14 pin cerdip chip is, markings:
| 1 1124 1155B | | 0 F 7331 < | 4 |
The '104' text baseline is rotated to left, and pin 1 indent to the right.
Picture at
Turned up in some junk parts a friend gave me.
Cheers, Grant.
Grant wrote in news: snipped-for-privacy@4ax.com:
Military markings? They use ceramic IC,s and might not want people to know what's in them.
Another thought: precursor to 74 logic series? I have no clue if there was ever a 73 series, btu if so you might have one there.
On Wed, 29 Sep 2010 07:39:20 +1000, Grant put finger to keyboard and composed:
Could the "7331" be a week 31, 1973 date code?
F = Fairchild ?
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Lostgallifreyan schrieb:
I'd rather think 7331 is the date code, and the type information is in the first line - maybe some custom code, and/or military.
The "F" could be an indicator for Fairchild as manufacturer.
Tilmann
Tilmann Reh wrote in news:i7unuv$1vv$ snipped-for-privacy@news.eternal-september.org:
31st week of 1973? If so that could fit, it looks old enough.
I wondered that too, but I don't know if firms were as logo-happy then as now. They got very flamboyant so we can't confuse them with anything else, but in those days I have no idea what they did. I think Fairchild are one of the oldest though, so I agree it might mean them.
Lostgallifreyan schrieb:
At least it appears possible. :-)
In those early years, Fairchild often printed just that single letter "F" on their ICs.
Tilmann
Or telecomms? I think the 7331 is data code, going be the age of the plastic tape around the IC carrier, a piece just long enough for one chip, perhaps carried as a spare?
Be my guess too. I have no idea what the chip is though.
Grant.
I don't know for sure, and looked at the photo first and my best guess was Fairchild and made in 1973 as well. The rest of the numbers don't mean much- could be house markings or something like a 12 gate IC that was discontinued in 1974.
If you have a Xeltek Eprom burner you can use it to identify many TTL and CMOS parts - I think a few other burners may have this function as well.
Or it may be a PROM
John :-#)#
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The thing is, circa 1973 (and that seems like a good guess, that the "7331" is the date code), ceramic packages were fairly common. It was kind of on a cusp, ICs were seeing a lot of use but nothing like what came later. A lot was still in ceramic, there wasn't yet enough demand to make it in a cheaper package. Remember, this was the time of 265bytes in a RAM IC, and only one-bit wide, or more likely long shift-registers for memory. I'm sure that RAM I bought at PolyPaks about 1973, not having more than
256bits, was a ceramic package.The 7400 series was usually plastic, but ceramic was not uncommon at that point (though, I'm not sure if just happened to come in ceramic, or if it was rejects from the tighter-spec'd 5400 series).
The point is that at that time, having a ceramic package might not be much use in defining the IC, other than it isn't likely to be a consumer-oriented IC.
Michael
May have been a house part for telecomms industry, as that's the area my friend worked in for a long time. I started working in electronics mid 70s and mostly opamp ICs where what I saw until late '70s.
Glad I'm not the only one wondering what the thing is.
Grant.
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