i've been debating releasing this for awhile, but here goes. it's a basic tilemapper. im releasing this right now as a beta (if you can call it that) since all i want is feedback.
some limitations:
1) tilemap editor cursor is inaccurate. i'm hoping to fix this by reordering the movement code.
2) you can't export the HEX string of the tilemap. my program won't display it, since it's obnoxiously long to copy anyway.
3) you cannot load/save tiles, even though it gives you an option to load a tilemap. that's for the future.
4) you can only navigate through the program tile editor -> tile mapper, as of right now.

buttons of use in tile editor:
arrows - move cursor
[2nd] - invert pixel
[ + ] - next tile
[ - ] - previous tile
[Alpha] - start tilemapping

buttons of use in tilemap editor:
arrows - move cursor
[2nd] - display next tile in tileset.
[ + ] - display tile number
[Clear] - exit program

this definitely isn't a useful program (yet). some of the things i'm hoping to implement:
1) compression techniques. 1 byte = 1 tile, 1 byte = 2 tiles and RLE. let me know if you want me to support any others.
2) saving/loading tilemaps and their corresponding tilesets.
3) more accurate cursors
4) 16x16 tiles. *maybe* unless i gain enough support, they're out.

TL;DR: download. find some bugs, think of useful features. post 'em.

the getkey() vs getkey->K thing i will experiment. then again, i could make there be two modes. i've done it before 

forgot about that. i just added it, thanks for reminding me. except i only added it for the tilemap editor, not the tileset. since at most, to get to the other edge you only need to move 8 pixels. on a tilemap i'll make it do that, though.

scrolling (maps larger than 12x8) will be implemented too, forgot to add that.

my main problem is tile selection. can anyone let me know how they would like to see a tilemap editor work? DJ, i can think of a few ways:
1) leave as is (with a button that will indicate to delete the tile being added)
2) have 1-9 and A-F be tile keys. so pressing 1 will get first tile, 2 = 2nd tile, 3 = 3rd, etc.
3) drop down menu displaying like so at the left side of the screen:
[tile 0][tile 8]
[tile 1][tile 9]
[tile 2][tile 10]
[tile 3][tile 11]
[tile 4][tile 12]
[tile 5][tile 13]
[tile 6][tile 14]
[tile 7][tile 15]
except the actual tile is visible there.
4) combine all three. 2nd would display the next tile, 1-9 + A-F would give corresponding tile, [Alpha] would open the menu.

thoughts?
also, i've decided copying tiles will be another feature. so you could copy the data from tile 1's memory slot to tile 5's memory and then go to tile 5 and be able to edit a variation of tile 1.

i'm going to give myself a challenge and do 2,3 and then +, - for next/previous tiles. DJ, should the tiles loop? like if i'm at my last tile, and i press +, should i stay at the last tile or should i loop back to no tile?

Yes, they should loop both ways.

I, personally, think the menu should depend on your tiles.  If you are using half-byte, you can have at most 16 tiles, so two rows at the right or left edge of the screen.  (Depending on where you are placing the tile.)

I also would like cross-linking tiles.  Eg.  Teleport, or doors.

cross linking tiles are something to code by your own in your program. It cannot be implemented in a tilemap. The trick is to make sure to group teleport tiles together if you have many so if conditions are easier to write.

Nemo: Yeah, kinda, altough make sure it's to the upper left when moving the cursor to the right half, down when moving cursor to the upper half and vice versa, so it won't always hide the first tile in the map

Yeah I often had issues with the left key

Kinda annoying at times. I think it's the key delay not being long enough or something. You migth want to report this to Quigibo in case

Sounds like a good deal. Good luck

aaah ok ^^ Hopefully Quigibo implement geometry drawing soon