cartridges with missing copper pegs on the rom chip?

[RetroRich]

if a cart is missing some of the copper colored things on the rom chip, does that mean the game is pretty much unfixable and broken?

[skaar]

Things are necessary for things to work.

Pics to specify what things help.

[RetroRich]

i'm talking about the gold pins on the bottom of tis circuit board. some of them are missing.

[Ro-J]

Is this what you mean?


If that's the case, then no worries, they should work fine.

[crazyjackcsa]

For a guy with Retro in your name, you have a lot to learn


I'm going to assume this is related to your other thread.

Some Sega Genesis games just didn't have all the connectors. They came like that from the factory. Nothing more to it. They are missing, sure, but they haven't been removed.

I've noticed it more on third party games late in the life of the system. Why? I honestly have no idea.

Relax, there is nothing to repair.

[RetroRich]

i don't really know the technicality behind the rom chips of the games, and never owned a genesis back in the day, so i do admit i'm a newb at stuff like this.

thanks for the info though

[Tokimemofan]

On SNES carts some pins were used for expansion CPUs and other cartridge specific features. some manufacturers removed the connectors that weren't used, possibly to avoid needing to gold plate functionless parts.

[APE992]

They're called "golden fingers".

A good chunk of SNES carts didn't have them and the theory that they were used for expansion universally isn't true. Pop StarFox onto a GameGenie (which doesn't support the extra connector on either side) and you'll find it works just fine. Might not be the case with StarOcean or MMX3 but it is not a universal.

[jb143]

Going off the picture that Ro-J posted you can see that it's pins 15-20 that are not being used. Looking at a pinout it's easy to see what they are and why they might not be needed.

Here's the specs...
B15 HS_CLK
B16 !C_OE
B17 !C_CE
B18 !AS
B19 CLK
B20 !DTACK

The CLK's are clock signals. Specific frequency outputs coming from the Genesis itself. I can't really think of why a game would need these.
OE and CE are cartridge ROM output and chip enable. I'm pretty sure they are used to tell the cartridge what memory banks you wish to access(only needed for larger games)
I think AS is Address Strobe, which is a pin on the Genesis processor itself. It would be used to tell external devices that there is a valid memory address on address lines. This probably also wouldn't be of any use for a small game(but might on a large game with more complex address decoding...or an external device with it's own possessor)
DTACK is Data Transfer Acknowledge. It signals the processor that data is available. It looks like the Genesis generally doesn't need to make use of it though.
(Note: Don't take any of this as fact. I haven't looked too much into the Genesis's inner workings but is mainly assumed on my part from a general understanding of databusses)

The basic idea is that if a cartridge doesn't need the signal then why bother having a trace for it? They are gold plated and add unnecessary costs. Also, some of these pins are probably never needed by cartridges and were added for future devices...such as the 32X.

[APE992]

That picture is actually the PCB from a NES cart. One of games these actually:

http://bootgod.dyndns.org:7777/searc...-04&kwtype=pcb

[Loremaster]

Going off the picture that Ro-J posted you can see that it's pins 15-20 that are not being used. Looking at a pinout it's easy to see what they are and why they might not be needed.

Here's the specs...
B15 HS_CLK
B16 !C_OE
B17 !C_CE
B18 !AS
B19 CLK
B20 !DTACK

The CLK's are clock signals. Specific frequency outputs coming from the Genesis itself. I can't really think of why a game would need these.
OE and CE are cartridge ROM output and chip enable. I'm pretty sure they are used to tell the cartridge what memory banks you wish to access(only needed for larger games)
I think AS is Address Strobe, which is a pin on the Genesis processor itself. It would be used to tell external devices that there is a valid memory address on address lines. This probably also wouldn't be of any use for a small game(but might on a large game with more complex address decoding...or an external device with it's own possessor)
DTACK is Data Transfer Acknowledge. It signals the processor that data is available. It looks like the Genesis generally doesn't need to make use of it though.
(Note: Don't take any of this as fact. I haven't looked too much into the Genesis's inner workings but is mainly assumed on my part from a general understanding of databusses)

The basic idea is that if a cartridge doesn't need the signal then why bother having a trace for it? They are gold plated and add unnecessary costs. Also, some of these pins are probably never needed by cartridges and were added for future devices...such as the 32X.

Thought I'd just chime in here...

I've never worked with the Genesis hardware specifically, but I have dealt with the Motorola 68k processor that it uses. AS and DTACK are rather important for the processor to function. DTACK is a signal sent from the chip back to the processor. If the processor fires Address Strobe and does not receive a DTACK reply, it will just sit there, waiting. In fact, on a board I built with the 68k for school, the DTACK not asserting was a HUGE problem [turned out to be related to a bug in the address decoding hardware, but I digress].

I realize that cart is actually NES, but just thought I'd add a little more knowledge to this great thread. Speaking of the topic, anyone got a website that details the cartridge slot pinouts of the various consoles?

[jb143]

oops...double post

[jb143]

From the info I came across, DTACK and AS are not generally used or needed by the cartridge. The DTACK signal is used internally by the processor of course but not necessarily the data going into the cart.

I never even considered that the picture wasn't a Genesis cart, since the pinout lined up with 5 pins that weren't always necessary.

Here's one of the sites I came across looking for references.

Edit...
And here's a picture of an actual Genesis cart PCB where B18 and B20 are clearly not used.

[APE992]

That is a Blockbuster Game Factory PCB, not remotely a "normal" Genesis cartridge either. They were essentially flash carts (you'll note the dual Intel flash chips) that Blockbuster downloaded ROMs over ISDN lines (or better) and flashed onto the cart to rent out to someone.

I wouldn't want to use that particular example as something common place but your point is taken.

http://www.assemblergames.com/forums...d.php?p=547349

[Loremaster]

From the info I came across, DTACK and AS are not generally used or needed by the cartridge. The DTACK signal is used internally by the processor of course but not necessarily the data going into the cart.

I never even considered that the picture wasn't a Genesis cart, since the pinout lined up with 5 pins that weren't always necessary.

Here's one of the sites I came across looking for references.

Edit...
And here's a picture of an actual Genesis cart PCB where B18 and B20 are clearly not used.

I did a little more reading on the 68K, and have found an answer. Turns out we're both right.

In high-speed designs where it can be assumed that read cycles will be very fast [i.e., not the limiting factor], then DTACK can be held low [that is, constantly asserted], so that the processor can run programs as fast as possible.

I'm assuming that DTACK is tied to a pull-down resistor within the Genesis hardware, so that simple single-chip carts or carts with higher read-speed ROMs won't need that pin, and as such it will be constantly asserted.