Category: memory management
INT 21 - Quarterdeck DOS-UP.SYS v2.00 - INSTALLATION CHECK AX = 2B01h CX = 444Dh ('DM') DX = 4158h ('AX') Return: AX = 0000h if installed BX = DOS-UP version (BH = minor, BL = major) CX = 4845h ('HE') DX = 5245h ('RE') ES = DOS-UP driver segment