IC / chip orientation vs text

tstone

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Just a random musing here...

I've been looking over a pile of boards I recently received, and found it odd that one of the chips on one of the boards had text "upside down" with respect to all the other chips on the board.

I got to reading, and found some sites that say that you can find pin 1 or the notch just by considering it to be to the lower left of the text. Like this site: http://www.evilmadscientist.com/2010/basics-finding-pin-1/ ("The text orientation is consistent, and for chips of this shape (with pins on two opposite sides), you can reliably assume that the polarity mark goes to the left of the text.")

This pin has the dot and notch, which I rely on, and it's not to the left of the text, and ALL of the text is upside down compared to every single other chip on the board. See pic.

I think this might have confused someone else at some point, because on this board, every single ROM, which are near this chip, was installed backwards (sigh).

After I got the ROMs replaced and the board fully working...that one chip's text is upside down compared to all the others.

Is this common? Is the text orientation completely random? I found at least 3 sites that said you could rely on the text...just misinformation? Or is this a super uncommon misprint?
 
Although rare, there was an old time manufacturer that did mark them upside-down. I forgot what brand it was. Haven't seen this in a long, long time. Extreme majority of time you will see text oriented as in the link you provided (or rotated as on larger EPROMs).
So, no you can NOT rely on the text for orientation of ICs but it does give you a 99+% chance of which way it will go.
 
Unable to upload the pic, sigh. It's 16k but still won't go for some reason.

This is an AMI chip.

Even the plastic "AMI" logo molded into the physical chip is upside down.
 
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pic

Here's the pic:

https://postimg.org/image/6zwv2nadj

6zwv2nadj
 
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