Zelda SNROM-01 Board Question

[zoiks66 | 72]

I have 2 copies of Legend of Zelda for the NES.  Both carts are early prints of the game that are 5-screw with TM on the label.  The boards are slightly different for each cart.  I’ve attached photos.  Can anyone tell me anything about the board that has what seems to be a circled 1 printed on the PCB below where it says Nintendo in the corner?  I can’t find any pictures of a similar board online and am wondering if it’s possible to tell which board was made earlier.

[0xDEAFC0DE | 1,277]

The standard way to date carts is by taking the latest date codes on the chips. It's not foolproof, but usually good enough. The top one has a lock out chip dated 8723 (23rd week of 1987) and the bottom one has a mapper chip dated 8722 (22nd week of 1987). So, I would guess the bottom one was made a week earlier. As far as the PCBs I assume those are production marks and probably not relevant. I out of the 12 pictures I have of NES tm PCBs, 2 have a partially circled I/1 like yours, 3 have a fully circled I/1, 3 have an S, and 4 are blank.

[Tyree_Cooper | 853]

Both have chips dated 8721 so my guess is to look at the ROM chip. The top one says 8720, while the bottom one has a more obscure 0209 7E3 A0. If we could decipher this into a production date, we could confirm the bottom one is earlier or not.

I don't know what the circled 1 is. Maybe a subrevision? Or a plant code?

I think the date is in the "7E3", I guess 7 is 1987, and E3 is the week... or maybe not. Any help?

Edited April 15, 2021 by Tyree_Cooper

[0xDEAFC0DE | 1,277]

12 minutes ago, Tyree_Cooper said:

Both have chips dated 8721 so my guess is to look at the ROM chip. The top one says 8720, while the bottom one has a more obscure 0209 7E3 A0. If we could decipher this into a production date, we could confirm the bottom one is earlier or not.

I don't know what the circled 1 is. Maybe a subrevision? Or a plant code?

I think the date is in the "7E3", I guess 7 is 1987, and E3 is the week... or maybe not. Any help?

The E3 is the third week of May (E = 5th letter = 5th month) which is equivalent to 8720. However the lock out and mapper chips have later date codes. 

[Tyree_Cooper | 853]

didn't they stop using this method of dating? looks like the very end batch, before they moved to "8720" ?? could be made at the same time as the other cart with the last batch of older rom chips, just before or just after, hard to tell. the battery is from a month earlier though

i know they mixed whatever they had, i think those carts are a good example, some items are a bit older, some a bit earlier, in the end it's very close

 

Do you know what the circle 1 means?

[zoiks66 | 72]

Thanks for the info.