What explains the unintuitive numbering of chip pins?

I think this is wrong. Pins really pads that are numbered on the die. The die is square (or was back then). Pads are numbered in sequence around the pad ring. So the concept of columns doesn't exist in the context of the die. As to why number counterclockwise vs clockwise, possibly that's to do with existing convention from valves. However note that in the beginning dual inline packaging wasn't the norm. There were flip chip packages, die on board, circular TO-xx metal can packages etc. So whatever led to the counterclockwise numbering convention certainly predated DIL packages.

The only pin numbering I ever perceived as unintuitive is on PLCC packages where pin 1 is in the <i>middle</i> of one of the 4 sides. Especially since there&#x27;s still a marker dot in one of the <i>corners</i> generally.<p>Luckily, PLCCs are rare these days.<p>Example: <a href="https:&#x2F;&#x2F;www.zilog.com&#x2F;manage_directlink.php?filepath=docs&#x2F;z80&#x2F;ps0180&amp;extn=.pdf" rel="nofollow">https:&#x2F;&#x2F;www.zilog.com&#x2F;manage_directlink.php?filepath=docs&#x2F;z8...</a> (Note that the orientation on the PLCC package is indicated by one of the corners being different, yet that&#x27;s not where pin 1 is.)

&gt; Why are pins counter-intuitively numbered in a rotating fashion rather than by columns as one would expect for a rectangular package?<p>I am not sure why this is counter intuitive, on a 8 pin package, it makes sense to keep pin 5 close to pin 4 to simplify the layout of the wires, and in general, it makes sense to keep consecutive pins close to one another. This applies to vacuum tubes as well.

Well, we now have packages where pins are on 4 sides (not just 2 sides). For example [1]. So here it certainly makes sense that numbering goes around the package instead of in columns&#x2F;rows.<p>[1] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Quad_Flat_Package" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Quad_Flat_Package</a>

Why would a convention be considered unintuitive? You learn it and it&#x27;s just a design fact. I&#x27;m not sure I agree with the article - it seems like a case of human-pattern matching.

Also, when creating wire wrap circuits (<a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Wire_wrap" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Wire_wrap</a>) one works from the underside of the board, so the underside pin numbering image shown in the webpage is the pin numbering one follows while wire wrapping a circuit.

It seems like the author just wanted to write about something, and he chose something he&#x27;s not familiar with but what appears as quirky to him. I expected the article to talk about IC design and peripherals (the placement of which is what is actually something that might seem unintuitive at first to many, well perhaps more annoying than unintuitive).