I'e searched it up, but i can't find out how to compress tilemaps using RLE.  I saw how to decompress using the routine though.

Yeah I saw that, but it stores the compressed map into an appvar - How do I just get it to display the compressed map data?
EDIT: NEVAR MIND I SEE.

Which routine are you using?

This one http://www.omnimaga.org/index.php?PHPSESSID=42e30a9bce8fdd375ed37eb181ff9432&topic=1532.msg50859#msg50859

you could fill a safe ram area with 0's and then rather than export to an appvar, export to the safe ram and then use length([saferam]). or you just could keep a byte counter, everytime you write to the appvar, increment the counter accordingly.

actually, just kidding. my routine already keeps track of the size. variable D should contain the size.

Try instead of creating the appvar beforehand, compressing the map into L1, or a large piece of memory.  After you finish compression, you know the size and you can create the right sized appvar

Yep, that should work That is, are you able to write the compression routine in itself?  or do you need some pointers?

Okay, I modified Nemo's compression routine so it works fine except for one thing - it glitches whenever there are more than 16 of any hexadecimal value in a row, at which point it reads off the hex string into char randomness.
How to fix?

the routine compresses data into two nibbles. the first is frequency, the second is the tile number. though that shouldn't be happening because my routine does check to see if you're trying to put more than 14 (why 14? i can't say, i wrote that a long time ago.) into frequency. if you can give me uncompressed and compressed data, i could better identify the bug.