Info Catalog
as: Z80-Chars
as: Z80 Syntax
as: Z80-Case
9.55.2.2 Register Names ....................... The registers are referred to with the letters assigned to them by Zilog. In addition 'as' recognizes 'ixl' and 'ixh' as the least and most significant octet in 'ix', and similarly 'iyl' and 'iyh' as parts of 'iy'.