What I am doing is reading a barcode scanner that produces keyboard scan codes. I am having speed issues so I have had to produce the most tight code I have ever written in my life (no subroutines and very few jumps) and I have to just throw the scan codes into a temporary table until I finish reading (there are 13 bytes of scan codes). After I finish, I can actually DO something with the codes...which is where the three pointers come in.

I am using the dptr to point at the temporary table, r0 to point at the hex conversion table, and r1 to point at the permanent storage table. I take the data from the temp table, convert it, shift every other one to the left and or it with one that hasn't been shifted so that I am actually putting two hex values in one byte (to only use 7 bytes instead of 13), and store it in the permanent table. Life would be so much easier if I had time to do all of this while reading the barcode scanner the first time but I have had to reduce that code down to bare bones.