The hardest thing for me transitioning away from Motorola / MOS assembly code was the change over from AT&T syntax to Intel style.

A hex value or address is preceded by a dollar sign:

$C010 + $FE

$00:60:AA:B0:C1:FF

Etc...

Also, binary was a percent sign:

$0f = %00001111

Two bits per pixel was %%, allowing the digits 0 through 3.

There were lots of other differences but just too many to list here. Frankly, I don't miss those as much as I do the dollar sign for Hex.

To this day, I have to bend my brain into reading 0xC010 as $C010... Grrr....

Of course, one can commit the mortal sin of programming say, X86 using AT&T syntax.... Yeah, I can feel the rage from here still for having done that. LOLOL