Same BCC, but diffrent bins?

[JeepsAndGuns]

I found this kida odd. The reason I found out was just pure curiosity, still dont even know why I checked, but I did.
Heres what I found. I have a 7427 memcal, with the BCC of BNKM. Its a V8 $31 bin. It was what was in my spare 7427 I keep. I then bought another V8 memcal from another member, witch has the same BCC. I figured it would be handy to have a extra V8 memcal around.

When I got the memcal, I noticed it had a sticker on it with the BCC. It looks to be the same silver material and font as whats on the old 7747 chips I have. I thought this was odd, as the other memcal I have with the same BCC, has it "printed" on the blue cover itself. All the other memcals I have ever seen are the same way. They have the BCC printed on the body, no stickers.
There are also other numbers on there, and then stickers and more numbers on the actual chips.

On the "printed" memcal, it goes as follows:

DELCO
3480 BNKM

Then on the chip:
5125
1618
8020

On the "sticker" memcal, it goes as follows:

BNKM
1621
3479

Then on the chip:
6128
1618
8020

I took my memcal readout header and read both and saved them. Seeing the diffrences, something told me to compare them. So I loaded them up and used the diffrence finder in TP and it found a crapload of diffrences. 99.9% of them were in undefined areas, and the only defined areas was "platform ID (MSW)" and "platform ID (LSW)"
The sticker one has FFFF, while the printed one has 7F7F. What oes that mean?

So anyone have any clue as to what the diffrences might be that are in the undefined areas? And why one has a sticker instead of being printed? Could it be a factory replacement? I will attach the bins if anyone wants to look at them. The sticker ones is called BNKM-3479, and the printed one is BNKM-3480.

[RobertISaar]

i've seen this once or twice before... since all of the changes were in undefined areas, it sounds like an algorithm change.

[EagleMark]

and what does that mean?

One looked like filled spots with 00 and other looked like filled spots with FF. Why?

[jim_in_dorris]

I am not 100% positive on this, but IIRC when I was learning $0D I had a conversation with 98 about 0 fill versus FF fill. Before address $4000, nothing is changable, that is all RAM and Prom addresses, so it doesn't matter what is in there. If you are assembling it, you can use that as an equate area to define stuff you reference in the code.

[JeepsAndGuns]

and what does that mean?

One looked like filled spots with 00 and other looked like filled spots with FF. Why?

I noticed that too, most al of them was 00 on one, and FF on the other, but if you keep scrolling down, you will see some lines that have other numbers in them.

Jim, your saying its basicly changes in the code, and not the bin? What is, and why is it diffrent, when they are both the same BCC?

[EagleMark]

Jim, your saying its basicly changes in the code, and not the bin? What is, and why is it diffrent, when they are both the same BCC?

That is what I am wondering as well. I didn't look to see if the rest of hex in bin area was same, just thought it strange that same bin changed ram area from 00 to FF? 00 in decimal is 000 and FF in decimal is 255. One extreme to the other...

[historystamp]

BitHoist gives these results, not that I know how to interpret.

Picture 1.png