The M Network mold variations are extensive, and sometimes so subtle, they are hard to tell the difference. I'm going to show and explain each variation, with arrows pointing at exactly what you should be looking for. One thing to know is that the easiest way to tell some of the differences is to have a ruler handy.
M Network cartridges are shaped much differently than other Atari games. They
consist of two parts, the long cartridge part which holds the circuit board, and
a wide base, which is made to fit into the Atari 2600 system cartridge slot.
are 9 different cartridge types for M Network games. The descriptions cover
the cartridge itself. It will refer to the long skinny part. There are also
versions with “M Network” molded into the plastic
of the base, and will be so noted in the actual label variations.
CART: snap piece: This cart has a 2.5” x 2.5” square piece in the back that
is not part of the main cart, and snaps into place. “© MATTEL INC” is
near the base.
CART: line at base: This cart has a raised line near the base on the back. No ©
CART: line at grips: This cart has a raised line on the back, up towards the
label, parallel to the grips. No © on cartridge.
CART: Mattel at base-small ©: This cart has a small “© MATTEL INC” near
the base on back. “MATTEL INC is 18mm
long. © is even with “MATTEL INC”
CART: Mattel at base-small Mattel stretched ©: This cart has “© MATTEL
INC” near the base on back. “MATTEL INC” is 16mm long. The c in © is
v9. CART: Mattel at base-large Mattel stretched ©: This cart has “© MATTEL INC” near the base on back. “MATTEL INC” is 19mm long. The c in © is elongated.
The first and easiest distinction in M Network carts is whether or not “M Network” is molded into the front of the cart at the top. Above you see that Armor Ambush does not have the “M Network” logo while Bump 'n' Jump does.
Above we have the first 3 of 9 variations for the back mold of the M Network games. I've labeled the versions as V1, V2, and V3. The exact descriptions are at the top of this page. V1 is the snap piece, which is a square piece of plastic that snaps into the cartridge to cover the components inside. I've put 4 arrows depicting the corners of the snap piece. V2 is the line at the base. There is no copyright on the mold, but a line going across near the bottom part of the cart that goes into the system. V3 is also a line, but it has moved towards the top by the side grips near the end label.
Above we have V4 on the left. This is the one where the copyright is up near the grips, towards the end label. The photo on the right is what versions 5 through 9 are. The copyright is near the base as shown. I forgot to put the white arrow, but you can see it. Since it is difficult to see the detail of the copyright, the next scan below will have V5 through V9 zoomed in on the copyright itself and labeled. You already know the location of where to look for the copyright as designated above.
Ok, here we go. I think I did a good job with this. Just note, the small, round, and stretched refer to the © itself. The width is now in millimeters. That is the length of “MATTEL INC”, measured from the beginning of the M to the end of the C, not including the ©. The detailed description is at the top of this page.