Using Registers
Putting some number in these registers is quite simple once you realize
how they work. Assuming you are using debug, just type in "R
{enter}".
You should see a bunch of info, of which are four of the above mentioned
registers. Now, type in "RAX {enter}". Then
type in a number like 8FABh. Type in "R"
again and noticed how the accumulator (AX) has change its number.
These general purpose registers can also be "split" in half into its
higher and lower order components. Instead of having one register AX, you
can have two registers, AH and AL. Note however that while you have a range
of 0 to FFFFh for AX, you will now have a range of 0 to FF for AH and AL.
You cannot change these directly in debug, but be aware that programs will
use it. If AX contains 0A4Ch, then AH will contain 0Ah and AL will contain
4Ch.