Hi, I don't check in often unless I'm writing for pics at the time...

I'm going to get ports wrong if I guess here, given that it's years old now,
so just to describe how the rows and columns are defined... the display is
8 LEDs high to fit one column in a byte, so since it's a mono colour display,
the whole display buffer is 18 bytes
I use in line assembler (if I remember correctly), or an asm/PBP combination
to address the bits of each byte in each column.
C0 - C17 are the bytes for each column, they are being strobed in the draw screen routine.