The Pokédex Glitch is a glitch exclusive to FireRed and LeafGreen US v1.0. The species names present are cut off, most specifically those species names made up of more than one word with a space in between. This causes Pokémon like Squirtle to be listed as "Tiny Pokémon" rather than "Tiny Turtle Pokémon." This was addressed in later releases of the games.
Here's a part of the routine disassembled from FireRed US v1.0:
The very first byte of the species name is loaded. If this byte is 0x0, no name will be loaded because the routine would treat that as an empty string.
Going on with the routine, there are some other instructions, but we just need to focus on the second cmp. There, the current name byte is checked to see if the end of the string was reached yet.
A blank space (0x0) is confused for the terminating byte (0xFF), basically. Now, changing the cmp instructions a little:
I wonder what other differences between v1.0 and v1.1 are.
Thank you. And I wonder too. AFAIK, there are not many differences at all. Except the said glitch, and the presents screen, I wouldn't really know.
Comparing the ROMs is not a solution because all the data got shifted, making all offsets and pointers different.
Since the thread revival limit does not apply here.... I noticed this way back in '04 when I got FireRed (I still have that cartridge, and the Wireless Adapter that came with it). At the time, I thought that they were going to stick with not having the full species name thing in future games. I also didn't know that they fixed it in later versions of Fire Red.