Hi, i ll like some help with some translations of maple's functions to mathematica

i have this

A :=diff(y(t),t,t)=-0.3*a*d1*diff(y(t),t)

H:=evalf(h*Pi/120)

st:=stop_cond=[diff(x(t),t)];

tmax:=eval(t,n);

K:=dsolve({A,B,ic},{y(t),x(t)},type=numeric,st);

if anyone can translate any of this to mathematica i ll be greatful!

cheers