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View topic - MkIII F-16 My Card vairants?

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  • Joined: 05 Nov 2014
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MkIII F-16 My Card vairants?
Post Posted: Thu May 30, 2019 12:10 pm
Ive been buying a few "card" games lately and have come across 2 different variants of F-16 for the MkIII. One has the code C-508E and 549 on it, the other has C-508EE and 547 on it.

I don't have my master system 1 handy at the moment so am unable to test them on that, but i have tested them with a SMS to MkIII adapter and a card catcher on a modded SMS2 (with JP bios). Both copies were brought off ebay in "working" condition, but they behave differently.

The one with C-508E on it refuses to load and goes straight to the bios. It happens very very quickly, almost indicating that its not able to detect it at all.

The one with C-508EE on it loads fine.

What i find interesting is that the one that works (C-508EE) has some extra lines printed on it that look like they could possibly be connecting some of the card pins together, or possibly covering up some sort of rework. The lines mostly go between address pins, which doesn't make too much sense. Ill take it to work tomorrow and have a look under the xray and see if i can see anything different going on inside it.


Does any one know why this is so? And or if any other games had a similar type of thing?
20190530_234228.jpg (246.09 KB)
20190530_234228.jpg

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Post Posted: Thu May 30, 2019 4:53 pm
The fact that you can visibly see added traces is pretty odd but its a good sign for a hardware revision on a cart/cart.
I assume all the extra pins are being pulled by the center ground pin unless its layered and only A9 is to GND.
from what I can see its.

A9 <> GND
A11 <> A3
MO-7 <> A2
A10 <> A1

This is kind of odd but also not really if its for "bank swapping" if you want to call it that. As far as Software Revision theory goes, its pretty normal to see slightly different carts/cards/discs pop up featuring revision codes on them that dont totally match another release or even having totally different artwork on them.
If you can get the non working one to boot then awesome else I personally wouldn't rule out that the non working card is some fake made to rip someone off. It's highly possible, given the size of the card it would be extremely cheap to make a plastic dummy.
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Post Posted: Thu May 30, 2019 6:41 pm
I guess it would be easy enough to check for continuity between the apparently joined pins.
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Post Posted: Fri May 31, 2019 12:59 am
It looks like theres a print of carbon ink under those lines. Its roughly 35k ohms between all of them.. so pull down resistance looks like the reason.

The carbon doesnt show up under the xray but other than that, both copies look the same internally.

Interestingly enough the US copy of f-16 is a little different inside. Its got little sets of pads with carbon ink between them allowing for the posability of different pinout configurations, rather than being tracked straight to the connector pins like the MkIII one.

Ill attach some pictures once i can get near a computer.
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Post Posted: Fri May 31, 2019 10:35 am
Here are some pictures showing the same spot inside the cards. The one with the extra pads is the US version
20190531_124353.jpg (183.23 KB)
20190531_124353.jpg
20190531_124416.jpg (228.89 KB)
20190531_124416.jpg

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Post Posted: Thu Jun 06, 2019 11:13 am
Ive had a little play with this.

Both copies work fine on a pal master system 1 in the card slot and using a boot loader.

The copy with the extra printing on it (C-508EE) works fine in a card catcher with a MkIII to SMS adapter, also using a boot loader. However, the copy without the extra printing (C-508E) will not work in the same setup.

I can only then assume the carbon ink is used as pull down resistance to compensate for some difference caused by the card catcher.

1) In the card catcher the address lines all go straight through to the same pins on the MkIII edge connector, if they didn't then it wouldn't work. Don't see why pull down resistance should help here as the CPU will drive these lines.

2) The MkIII slot doesn't have M0-7. This goes from M0-7 on the card socket to A15 on the MkIII edge connector. In theory they are the same thing, so not sure what effect pull down is going to have here either as the CPU is also driving A15.

On the card catcher i noticed that /MemReq on the card socket is connected to /CSRAM on the MkIII edge connector. This would be pulled low by the MkIII, so /MemReq on the card socket is always active. /CE on the card socket is also connected to /MemReq on the MkIII card edge.
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Post Posted: Thu Jun 06, 2019 12:48 pm
If you have a way to do a memory dump then maybe we can see if there's a region check going on. Some games may even do this by counting scanlines before a vblank to detect PAL or NTSC. Either way, if you can, you should see if it loads on other variants of the platform.
once again just assumptions and speculations.
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Post Posted: Tue Jun 18, 2019 10:52 am
Was just reading another post and spotted the same extra lines printed on one of the my card ep pictured in this discussion.

http://www.smspower.org/forums/6225-EPMyCard

It must not be an uncommon thing then. I still think its to add compatibility for the card catcher, although i havn't bothered to trace it all the way through and get to the bottom of what the exact differences are.
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Post Posted: Tue Jun 18, 2019 2:58 pm
interesting... just looking at the MO-7 line, its a different connection on this and the card in that link... What is MO-7 even used for?
Im also now convinced that these extra traces are all grounding these lines, the question still is, why?

Your Card
A11 <> GND
A10 <> GND
A9 <> GND
A3 <> GND
A2 <> GND
A1 <> GND
MO-7 <> GND

Card from Link
A11 <> GND
A10 <> GND
A9 <> GND
MO-7 <> GND
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Post Posted: Tue Jun 18, 2019 11:30 pm
M0-7 is esentially the same as A15. On the card catcher its actually connected to A15. I assume internally its connected to either /CE or /OE like they do on 32k carts.

The extra printing is definately resistive and pulls the pins to ground. That my card ep used 2 separate ground connections.. possibly its got 2 different resistive inks to give different pull down values?

I might pull apart a card catcher and solder some resistors on to all of those pins and see if the copy of f-16 that doesnt work in a card catcher starts working.
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