"1943: The Battle of Midway" is the second in a series of highly successful vertical-scrolling airplane shoot'em up games from Capcom. I find it rather ironic that although the game bears a stern warning that it is NOT to be played outside Japan, all the enemy planes in the game have Japanese national markings, the goodies' airplanes have USAF markings, and one of the game sound effects is the American national anthem (presumably played when the game is complete). Very non-patriotic for a Japanese game!
The manual for this game gives a little historical background for the game's title; apparently, there was a decisive battle during World War 2 in the Midway Islands, where the Americans defeated the Japanese. It's really hard to understand why this game would be released with such a political loading; why didn't they just make it a generic shooter? Is this Japan's apology for Pearl Harbor? The intro to the game shows your plane (and player 2's plane, if it's a multiplayer game) sitting on the deck of an aircraft carrier, just as in 1942. A fleet of Japanese planes comes along and bombs the carrier, and the ship develops a list to port. Your planes then take off from the sloping deck to deal out some incendiary havoc.
Incidentally: There are a LOT of hidden cheats in 1943. Holding down certain joystick/button combos at the start of particular levels will give you special weapons, and there are also strange bonus items which appear sometimes (a cow, a cat, a barrel and a lump of something I don't recognize).
It has taken me a long time to document this board, because it means twisting the tube in one of my cabinets to make it a vertical monitor. Almost all the games I really enjoy run on horizontal monitors.
My 1943 is probably a bootleg, though it's difficult to tell; it actually looks a lot like my 1942, which I know to be genuine. The board is based around two Z-80As. Audio output is provided by two YM2203s; one does the sound effects and a couple of short snippets of music, the other handles the background music. Both are controlled by a single Z-80A. My board had an annoying sound fault, where the background music was overlayed by strange noises (I remember this fault cropping up in the 1943 machine at university, too). By poking about in the audio section, I found firstly that the board had single-wipe sockets, and the audio ROM was intermittent - I replaced this socket, and that was OK, but the fault was still present. Sterner measures time!
By tying _CS from each YM2203 to +5V with a test lead, I was able to establish which of the chips handled music and which handled sound effects. It turned out that force-disabling either chip made the other chip work perfectly. Thus, it appeared to be a case of the FX chip sometimes being selected incorrectly when the sound CPU was passing data to the music chip. I traced _CS from the FX chip to a 74LS74 (dual D flip-flop), and replaced this chip. Voila - correct sound.
Fixed! Or... not quite! Occasionally, the machine STILL wouldn't make a sound. Manually resetting the sound CPU would restore normal functionality. It seems that the Z-80A which controls the audio wasn't getting a wide enough reset pulse on powerup. I added a small electrolytic capacitor between _RESET (of the audio CPU) and ground, and FINALLY my board is 100%. Phew!
1943 uses a vertical low-res monitor, one or two 8-way joysticks with two buttons, and it has a standard JAMMA pinout. DIP switch settings are below. NOTE: My board has the numbering reversed, ie the DIP switch modules were inserted the wrong way round during manufacture. Yours may be the same! * = factory default setting.
DIP Switch Bank A
DIP Switch Bank B