What is the difference between multi-tile encoding and dictionary compression? I've tried finding the answer to this question in several documents but the only thing I can seem to fathom is that MTE refers to a system where one byte correlates to a few characters whereas with dictionary compression, a byte correlates to a full word. That would indicate that it's purely a matter of semantics. (I'm just about positive that DTE vs MTE is purely a matter of how many tiles a byte references.)

However, there is a document on this site that explains how to implement a "combined DTE and dictionary compression scheme" which obviously suggests that they are two separate entities.

To avert anyone from going too in depth with their answer, let me state that I am not terribly interested in the coding side of the issue. I am simply hacking a game that uses one of these and I'd like to know exactly which one it is so I don't sound stupid when talking about it.

Hi and welcome to RHDN

These two terms are usually loosely used interchangably. Originally, it really meant a tile encoding. That is, one hex value equals two tiles on a tile-based system. So for instance, 0x0A prints Tiles 「１」「０」 (two tiles). Now, multi tile encoding would stretch that even further. You can say DTE ⊂ MTE.
However, nowadays, MTE is also used to mean that one value can in fact represent a whole word. This is obviously dictionary encoding. These two are somewhat related, because there could be a lookup table in place that says 0x0A = 0x01 0x00 for instance (and these would represent, to keep the example from above, the tiles 「１」「０」 resp.). So the MTE and DTE effect can be achieved by having a dictionary in place.
Also, there is sometimes also references to a DTE that works the other way around. It will take two regular bytes and print their values into one Tile. For instance 0x01 0x00 would represent "10" in the Rom (as plain text, just as an example). However, in the game, to save screen space, these would be rendered as 「10」, inside one tile. This is however, usually referred to as half-width font, however, there is some confusion about this out there and some people use DTE to mean this system.

I hope this cleared stuff up a bit... Or maybe enhanced the trauma :O

cYa,

Tauwasser

So MTE doesn't necessarily have a lookup table in place? Would this mean that the values would be hard coded and require assembly to change? Or did I misunderstand something?

They all have a look up table. Unless for some asinine reason you hardcode everything:


That's just a waste of space and time.