I agree, I'm trying to decipher assembly but man it's still functionally greek to me. I've read and am re-reading the posted tutorials but it's just really cloudy.
Not giving up though.
You don't really need to understand much to modify the graphics in the asm. Really you just need to know how to assemble it to a .bin so you can test it. Have you tried the following?
1. Open the .asm I attached in my previous post in a text editor of your choice.
2. search for MPH
3. change the 1's and 0's to produce the desired MPH graphic and save the asm file.
4. Assemble with dasm. There's a bunch of ways to do this. This simplest is to call dasm from the command line with the path of the asm file. On windows I use a small batch file which assembles it and then runs it.
SET progpath=%~dp1 SET fileName=%~n1 dasm.exe "%progpath%%fileName%.asm" -f3 "-o%progpath%%fileName%.bin" "-l%progpath%%fileName%.lst" "-s%progpath%%fileName%.sym" -v5 "%progpath%%fileName%.bin"
but you can get away with just running
dasm.exe "C:\path\file.asm" -f3 "-oC:\path\file.bin"