INT 21 P - Phar Lap 386/DOS-Extender v3.0+ - READ/WRITE SYSTEM REGISTERS AX = 2535h EBX = direction (00h read registers, 01h write) DS:EDX -> system register record (see #01375) Return: CF clear Note: this call is only available under MS Windows if PHARLAP.386 VDD is installed Format of Phar Lap system register record: Offset Size Description (Table 01375) 00h DWORDDoubleword; four bytes. Commonly used to hold a 32-bit segment:offset or selector:offset address. CR0 04h 4 DWORDs DR0,DR1,DR2,DR3 14h 2 DWORDs reserved 1Ch 2 DWORDs DR6,DR7 24h 3 DWORDs reserved