It really depends on the situation which constraint is the most dire, but I think CHR space is a big reason that a lot of Japanese games used English characters exclusively. Especially before CHR banking was common. On the FDS disk load times to swap in those characters are a big issue, too.Great Hierophant wrote:Japanese text takes less space in terms of text strings than English text to convey the same ideas, most of the time. But I never appreciated the fact that Japanese text characters require more graphics tile storage space than U.S. text characters. Kanji usually takes a 16x16 cell to display legibly, which is the equivalent of four U.S. letters. Later systems usually have a lot more memory and you usually see fewer instances of blocks of English text.Nicole wrote:One practical reason: Japanese requires more tiles. Even with katakana alone, you're going to need about 50 or so tiles minimum. Compare this to English with its 26 letters. That said, the town dialogue is indeed in katakana, where I'm guessing they set aside more CHR RAM for text.
The biggest chunk of English text is probably the intro text, and it's not really essential to play the game. Not only that, the same information is probably in Japanese in the instruction manual.
I know the Zelda 2 U.S. manual tells the story in a grammatically correct and perfectly intelligible manner, I assume the Zelda 2 Japanese story does the same for speakers of that language.
String space is less constrained, I think, and text tends to be very compressible (especially compared to CHR tiles).
There's some other constraints that are important too. Screen space is a big one. Since Japanese is typically shorter it does tend to take up less horizontal space, but at the same time it tends to require extra vertical spacing between lines to accommodate diacritic marks. Hiragana especially is hard to fit in an 8x8 box, so a blank vertical line in between also makes it easier to make them legible, so you can use all 8 lines instead of 7, leaving one blank for spacing.
The Castlevania 2 retranslation ROM-hack efforts took advantage of this; I think reclaiming those blank lines (not used in the official English translation) let them put more text in that box. Some of its notoriously poor translation might have partially been due to cramped screen space because of requiring longer English words but having the same every-second-line text system in place.
Though, applying to Zelda 2's title screen, I don't know if any of those constraints really mattered. It seems like the scroll split would have made it feasible to stick the katakana set on the other PPU page if they'd wanted to use it. It might very well have been that they just wanted it in English for other reasons already mentioned in this thread, and not technical ones.
