MAI Systems Corp.: The Irvine computer hardware and software company posted a profit of $4.5 million, or 78 cents a share, a 97% decline from earnings of $145.5 million, or $24.72 a share, for the previous year. The 1993 net income included a gain of $79.1 million from disposal of European operations and $60.4 million for bankruptcy-related gains. Annual revenue fell 43% to $66.1 million from $115.3 million. For the fourth quarter, MAI reported a profit of $4.3 million, or 74 cents a share, compared with $59.4 million, or $10.09 a share, for the final three months of 1993. Quarterly revenue declined 10% to $16.3 million from $18.1 million.