WIN_CHG
Set(f, WIN_CHG);
Set(f, WIN_CHG);
Set(f, WIN_CHG);
!Status(f, WIN_CHG))
Set(f, WIN_CHG);
if (current && Status(f, WIN_CHG)) {
Clr(f, WIN_CHG);
Set(f, WIN_CHG);
if (Status(f, WIN_CHG)) {
Clr(f, WIN_CHG);
Clr(p, WIN_CHG | BUF_CHG);
Clr(f, WIN_CHG | BUF_CHG);