I originally wrote this for the high score forum, but I'm not sure it goes there because it's sorta bigger in scope than just submissions. So I'll just post it here!
Some questions are being raised about Donkey Kong PCB hardware and ROM sets, what's valid and what isn't, etc., so here are some things I've learned over the past couple of years after a butt-ton of research on KLOV, etc.
There are THREE different Donkey Kong board sets: TKG-2, TKG-3, and TKG-4, and TWO different ROM sets.
The "TKG" numbers refer to the part numbers of the PCB sets, not to the ROM revision (which have no official name that I'm aware of, other than the MAME nomenclature "Set 1" and "Set 2").
There are, as far as I've been able to find, only those TWO ROM sets in the US, Japan had three, for five total.
The board set TKG part numbers have come to be semi-synonymous with the ROM revisions because of the semi-reliable correlation between the hardware and the software. People just use the PCB part number for simplicity and lack of a better term.
TKG-2s are actually not Donkey Kong boards at all. They're Radarscope boards that were hand-converted at the factory to DK, with "TKG-2" stickers over the original "TRS" part numbers. But I'm sure you all know THAT story by now.
Only 3,000 of these TKG-2s existed, and most are probably gone now. They would have shipped with the original code ("US Set 2" in MAME). But they will probably never be an issue as far as submissions are concerned. (And if somebody shows up with a working one of those, call me any time day or night. I will have cash in hand.
)
The TKG-3 boards were the first DKs that were NOT Radarscope conversions. They also would have shipped with the original code (US Set 2).
The TKG-4s were the newer, streamlined 2-board sets that Nintendo put into production as soon as DK started taking off in the arcades. These are found in the vast majority of all DK uprights produced. All TKG-4 boardsets shipped with the updated ROM code (US Set 1). So unless somebody "downgraded" their board to the original code, these will always be legit.
The TKG-2 and TKG-3 boardsets are not so simple. Some will have the older "Set 2" ROM code, some will have the newer "Set 1" code.
The updated ROMs were made available for purchase in December 1981 to any operator with a TKG-2 or 3. Nowadays, of course, anybody could burn a set. So any of those boards MAY OR MAY NOT have been updated to the newer code anytime between BITD (in the field by an arcade operator), up to this very moment (by a collector). The hardware will not show this.
The question of how cocktail scores should be handled was recently raised, so here's how that works: ALL non-fullsize DK machines (the cocktails and cabarets) used the TKG-3 board set. The TKG-4 two-board set will not fit in a cocktail or cabaret machine, so Nintendo kept using the 4-board for the odd-sized cabs, all the way to the end of production.
What this means though is that cocktails/cabarets produced later in the run, while containing TKG-3 boardsets, DID ship from the factory with the updated ROM code, and are legit.
Those that shipped with the updated ROM are TKG-3-7s. The older ones, which shipped with the original ROM, are TKG-3-6. But again, any TKG-3-6 COULD have been manually updated at any point between then and now, so a "-6" on the PCB doesn't necessarily rule out an updated ROM.
In other words, you can't tell anything just from looking at PCBs. TKG-3 boardsets should NOT be disqualified just because they're TKG-3 boardsets, because many of them either shipped, or were updated with, the updated ROM code. The TKG-4 requirement is an error in TG's rules (one that we should not inherit).
So what to do?
I've mentioned this before, but there is a simple way to differentiate the old ROMset from the updated set, and it's a lot easier than dissecting gameplay for use of the ladder cheat or looking at the physical hardware.
The title screen on the original ROM set says "(C) Nintendo 1981."
The updated set says "(C) 1981 Nintendo of America Inc."
It's really that simple.
So, just look at the title screen and you can see which version of the ROM is running (assuming that the owner hasn't hacked it, which takes things into a realm that we can't do anything about, other than to watch the game for oddities).
The DK running on the Braze kits (high score save, Foundry, and D2K) adds code for FREEPLAY and high score save, but is otherwise untouched and runs identically to the updated ROMs that shipped with the TKG-4s. Jeff Kulczycki would not have modified the actual gameplay code without making it known, would have had no reason to (and every reason NOT to), and after years in the field, nobody has been able to provide evidence of any gameplay differences. If these aren't legit, I can't imagine how.
Also, on the 60-in-1s, and possibly some other multiboards, the title screen says "(C) 1981". No "Nintendo of America Ltd." Otherwise, they appear to run the "Set 1" code, and (again) after years in the field, there is no evidence that anything is amiss, other than imperfect audio emulation.
To sum up...
GAME CODE-------------------------------
Original code (MAME: "US Set 2"):
Ladder cheat possible. Title screen: "(C) Nintendo 1981."
Updated code (MAME: "US Set 1"):
Ladder cheat patched. Title screen: "(C) 1981 Nintendo of America Inc."
HARDWARE--------------------------------
TKG-2: 4-board set Radarscope conversion.
Shipped with original code (US Set 2).
ROMs might have been upgraded after shipment.
TKG-3-6: 4-board set, second run of uprights and cocktails/cabarets.
Shipped with original code (US Set 2).
ROMs might have been upgraded after shipment.
TKG-3-7: 4-board set, third run of cocktails/cabarets.
Shipped with updated code (US Set 1).
TKG-4: 2-board set, third run of uprights.
Shipped with updated code (US Set 1).
Multiboards: There are many, but the most common 60-in-1 that everybody has seen in arcades, etc. is a JAMMA PCB that utilizes drivers written for MAME (as most multiboards do). These appear to use the "Set 1" code for Donkey Kong, except for the removal of "Nintendo of America Ltd." from the title screen.
Braze kits (HS save, Foundry, D2K): Daughtercard that plugs into Z80 slot on a TKG-3 or TKG-4 board. These kits bypass whatever ROMs are installed on the PCB and contain "Set 1" DK code, except additions for FREEPLAY and high score save.
So there you have it.
And for anyone who has not seen the famous "service bulletin," check out the attachment. (Re the header: "LMC" was a company that distributed games for Nintendo.)
