When a Nintendo Game Boy is turned on, it displays a logo read from the cartridge (looking like this) before starting the game. What does it display if there's no cartridge inserted from which to read the logo? And what happens after that?
3 Answers
Here's a selection of Game Boys I've dug out from my drawer:
The original Game Boy displays a solid black rectangle (and a ®) which scroll down from the top of the screen, in the same way that the Nintendo logo would if a cartridge were inserted. This image remains on the screen until the Game Boy is switched off.
(Note the difference with the picture of the Game Boy Pocket in Greenonline's answer, which has a vertical break in the middle of the rectangle.)
The Game Boy Color shows a coloured animation of the phrase Game Boy in the centre of the screen, while a smaller black rectangle (with ®) is shown below the animation. Again, this remains until switched off. If a cartridge is inserted, the word "Nintendo" is displayed instead of the black rectangle, and the cartridge boots after the animation is complete.
The Game Boy Advance (and SP) display a different coloured animation of the Game Boy phrase, without a Nintendo logo. (The Nintendo logo is shown if a cartridge is present.)
Bear in mind that the GB Advance line supports network booting from another Advance or a Gamecube via link cable. When turned on without a cartridge inserted, they wait for communication with the host device, then transfer software over the link cable to execute (indicated by the Nintendo logo appearing in a non-standard, pulsing color chosen by the host device).
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2The GBA linked to a Gamecube is actually an extension of what it does when connected to another GBA with a link cable and a single-cart multiplayer game inserted in the other GBA. The GBA to GBA functionality was the original use, the Gamecube just leveraged it later on to also allow remote loading of code to the GBA. The original Gameboy also has similar functionality to allow running of multiplayer games from a single cartridge over the link cable.– mnemJul 21, 2019 at 23:25
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5@mnem The original Game Boy does not have single-pak functionality. The GBA made multi-cart boot possible by adding additional code in the boot ROM and a 256KB RAM bank to hold the downloaded program - the Game Boys before it only had 8KB of RAM and did not read the link port during boot. Jul 22, 2019 at 0:13
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1On the GBA you can force the no games inserted scenario by pressing SELECT + START while the game boy logo is on the screen. If timed properly a sound will play and the word Nintendo on the bottom should disappear. You can resume loading your inserted game by pressing any button afterwards. Jul 22, 2019 at 8:14
To complement the previous answer on why this happens, the Game Boy contains a very small ROM that is executed by the CPU before running the cartridge.
One of its routines include checking if the cartridge contains a Nintendo logo (Nintendo used this as a way of controlling game distribution by use of trademark law). Then another routine checks if the cartridge is correctly inserted (by doing a checksum of the cartridge’s rom header).
The logo shown on the screen is actually fetched from the cartridge rom (not the gameboy’s one) so if there was any problem with the cartridge header (such as not being present at all) the system will receive garbage data, manifested as scrambled graphics.
Sources:
- The Ultimate Game Boy Talk (33c3)
- Booting the GameBoy with a custom logo
- I research the different architecture of consoles and write some interesting findings in my personal website
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Don't those checks occur after the Nintendo logo? Otherwise, why would it continue to try to read those zeroes after it knows the cartridge isn't inserted properly?– wizzwizz4 ♦Jul 21, 2019 at 8:45
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3Anecdotally, I've known a GB with a dirty / mis-inserted cartridge to scroll down a corrupted version of the Nintendo logo, and then sit there doing nothing (just like when there's no cartridge).– KazJul 21, 2019 at 10:01
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7Regarding, "Nintendo used this as a way of controlling game distribution by use of trademark law," if you have any references for this, it would be worth adding an answer to this question.– cjsJul 21, 2019 at 10:04
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@CurtJ.Sampson Yes, I’ve noticed after writing this there was that specific question and added a comment there as well, I could turn it into an answer if it’s what you were looking for?– RodrigoJul 21, 2019 at 10:18
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3@wizzwizz4 Sequence is initializing sound and graphics for logo display, then display and scroll the logo while playing sound. When done the logo data (0A8h) is compared to the cartridges image (0104h).Difference locks up the system in an infinite loop. When equal the 01Ah ROM bytes staring at 0134 are added up and checked to result in 00h. If yes, the Boot-ROM is flipped off aand execution continues with the ROM otherwise the seme infinite loop as before is executed (aka locked up)– RaffzahnJul 21, 2019 at 20:53
This is what a GameBoy Pocket does:
Two black blobs (and an ®) slowly descend from the top and come to rest half way down the screen.
Taken from the (somewhat interesting) video, What it looks like when you turn on a game boy without a game.
Other GameBoy versions (DMG, GBC) differ in behaviour, as Kaz's answer demonstrates.
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2Is that gap actually there by design? I know my GameBoy towards the end of its life started to develop columns of dead pixels which look pretty much like this picture. Jul 22, 2019 at 13:11
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That is a very good point. I took that image from the video. Unfortunately, after just attempting to check it myself, while I thought I had a GBP, in fact it is a GBC, so I am unable to verify this. Jul 23, 2019 at 7:53
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@DarrelHoffman My first Game Boy was a Pocket, which I parted with when getting a Color. I specifically recall the gap in the black pixels on the Pocket, as it wasn't there on my new Game Boy Color.– KazFeb 19, 2020 at 9:03