When researching flash cartridges, I keep coming across the term "RTC", but never see it actually defined. I think it has something to do with a battery powered clock. What does "RTC" stand for?

  • 24
    My brain went: Roller... Tycoon Coaster? Oh. Commented May 4, 2016 at 12:23
  • 16
    You mean: Roller Toaster Cy...cloon? Commented May 4, 2016 at 18:02
  • 1
    For me, RTC in Google results in the Wikipedia disambiguation page for RTC, followed by the Wikipedia page for real-time clock. I guess it may not be clear that that's your solution if you don't know what you're looking for.
    – DCShannon
    Commented May 4, 2016 at 19:01

3 Answers 3


RTC is indeed short for "Real Time Clock." What this indicates in terms of flash cartridges is a bit more complex.

Some games shipped with an internal clock chip that kept track of the time even when the system was powered off. They used this to measure actual, real world time for certain in-game events. Pokemon games in particular made heavy use of cart-based RTC chips in the GBA era. There's a list of games that rely on RTC (probably somewhat incomplete) over on Reddit.

In later handhelds (DS, 3DS, etc), the clock was a part of the handheld itself and not part of the cartridge. You'd set the time in the system's settings, and then games could read that time without having to resort to having their own RTC chip.

Flash carts that contain a RTC can make the time available to games flashed on them, which is an advantage if you plan to play games that used it.

Usually a flash cart with a RTC will also have an internal battery, which is another thing to consider - if the battery is difficult or impossible to recharge or replace, the lifetime of the RTC may be limited.

Granted, these batteries last a good 5-10 years easily, so the lifetime of the battery may not be an issue. However, this assumes you're buying one that was recently manufactured as opposed to one for an older system which has been sitting in storage for years already.

  • Cool! But why could not the system itself track time for the game?
    – Ostmeistro
    Commented May 6, 2016 at 9:31
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    @Ostmeistro: The second, third and fourth paragraphs address that. Commented May 6, 2016 at 10:51
  • @Ostmeistro, I'm guessing it was a design decision not to include a RTC in the systems at that time. Probably they didn't think it was worth the expense, it wasn't that common of a feature at the time, and hadn't thought of a reason why games would want it. After they started using it in games, it was probably cheaper to embed it rather than paying to ship one in every game. Plus, later games started coming on smaller carts (less room for battery) and/or discs that would have made including it harder/impossible.
    – agent86
    Commented May 6, 2016 at 12:30

RTC is short for Real Time Clock.


RTC - Real Time Clock served to keep track of date and time when the cartridge is without a power supply. In this Pokemon cartridge example you can see the battery that is powering the clock.

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You probably find that familiar from PC motherboards ;)

  • IIRC that battery also powered the volatile save storage. Or was that only on older GB carts?
    – Bob
    Commented May 7, 2016 at 14:45

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