pgmfi.org

I was trying to further my understanding of asm code and came across a difference between the Nx_800 book and the code dasm'ed by Andy's program.

In the book it shows
CLR A as opcode "FA" (DD = 1)
and
CLRB A as opcode "FB" (DD = 0)
In the dasm it seems to be different..

CLRB A shows as opcode "FA" (DD = 0)
CLR A shows as opcode "F9" (DD = 1)

I assume the dasm is correct and the book is wrong..? (Since the ROMs are working with this 'bug'..)

For nX-8/500S Core :

opcode "FA" (DD=1) = CLR A

opcode "FB" (DD=0) = CLRB A

opcode "FAxx" (DD=0) = LB A,#xx

So, does the 66201, 207,etc.. not really follow the Nx8_500s core?

My 273_stock ASM:




Note how it shows the opcode for clrb A is FA not FB
and CLR A opcode is F9 not FA
This is why I'm confused..