Spitfire on the Channel F is like the plane mode in Atari’s Combat, except with the option to play it alone against the machine. Also, I found an easter egg in it, which might (might) be the World’s First Easter Egg in a Videogame (maybe idk).
Here’s what the game looks like normally, for context:
I found the easter egg several months back by going through various Channel F games and viewing them as raw, 1 bit-per-pixel images using YY-CHR and seeing if I could spot anything interesting. Here’s what spitfire looks like arranged in a bunch of vertical stripes:
Most of it looks like static (machine code usually does), but towards the end of the file (the right side of the image) you can see some graphics, several letters smooshed together, some empty space, and a rather weird looking pattern at the end. Being intrigued, took a look at a raw disassembly to investigate.
The first thing the game does when turned on is ask you the timeless question: “G?” In response to this question, you are supposed to hit one of the 4 numbered buttons on the console itself to select a game mode. The modes are listed in the game’s instruction manual (this is a common (but not universal) design pattern for Channel F games). In the case of Spitfire, pressing “1” starts a 2-player game and pressing “2” starts a 1-player game against the CPU. Pressing “4” does nothing.
Pressing “3” also appears to do nothing, but it actually does something (invisibly). It jumps to a piece of code where you can enter a special passcode. The passcode is that weird-looking pattern at the end of the ROM. If you fail, you get sent back to the G? menu (also invisibly).
The passcode itself is 343242124133231432142314322132342334111223324443. (I have been unable to find any meaning to this sequence.) For those of you not counting at home, that’s 48 button presses, not counting the initial “3” from earlier.
If successful, you will see this screen appear:
…and then that screen will disappear as quickly as it appeared (given the system’s draw rate, that’s enough time to read it).
You can watch and listen to me input this code in this video:
This little easter egg, in addition to being basically impossible to find except through code analysis or divination, also takes up a hefty portion of the game’s ROM. The graphics for the text take up 110 bytes. The passcode itself takes 48 bytes. The routine that takes the passcode and prints the message is 61 bytes – and the code that branches from the initial G? menu to the passcode routine takes 7 bytes. That means, in total, this easter egg takes up a whopping 226 bytes of the game’s 2048 byte cartridge space, which is 11.04% of the cart. (And beyond this, let’s not forget the game also has 140 more bytes of empty space.)
Mr. Glass would later add a more simple to find easter egg to the Channel F “Democart” (intended for retail displays, I assume). By holding buttons 1, 3, and 4 at the end of its demo, a similar message appears. I didn’t find it, but here’s a video of it:
A later Channel F game, Video Whizball, has an easter egg of its own, where the last name of programmer Brad Reid-Selth would be put in the middle of the playfield as an obstacle. I didn’t find this either, but here’s a video of it:
Q: Is this the first very first video game easter egg?
Not sure. Halo 2600’s author Ed Fries found an easter egg in the arcade game Starship 1, and he was able to pin down the release date (or rather, its first public appearance) for that game down to August 13, 1977. Wikipedia lists the release date of Spitfire as being December 31, 1977 – however that date is unsourced and just feels inaccurate (like it was taken from a site that doesn’t support unspecified date/month fields). Further research on the matter is needed. According to this here post this game was advertised in a newspaper on April 15, 1977, meaning this game conclusively predates Starship 1.
EDIT (August 7, 2019): Due to an issue with the hardware of the cartridge itself, this easter egg is effectively disqualified. See this post for details.
Q: Did anyone else find this before you?
A: Not to my knowledge. Maybe privately, but not certainly not publicly.
Q: Do you know who Michael Glass is?
No. I found some results on Google for some fellows with that name, but I don’t feel comfortable asking any of them. Please scroll down to this post for more information.
Q: Can you post a video of you performing the easter egg?
Maybe when I figure out how to capture video from MESS on my laptop. Done.
Q: Hey could you post a line by line disassembly showing what’s going on in the code?
Not now. (plz pay me money so my day job becomes disassembling old games) A fellow named e5frog has graciously done one right here: http://channelf.se/veswiki/index.php?title=Disassembly:Videocart_4
Q: What’s the best place to find technical information on the Channel F?