INT 21 P - Phar Lap 386/DOS-Extender - CALL REAL-MODE PROCEDURE, REGISTERS AX = 2510h EBX = CS:IP(Internet Protocol) The lower level (transport layer) of the TCP/IP protocol suite. See also TCP, TCP/IP. of real-mode procedure to call ECX = number of two-byte words to copy to protected-mode stack to real-mode stack DS:EDX -> pointer to parameter block (see #01360) Return: CF clear if successful all segment registers unchanged, EDX unchanged all other general registers contain values set by real-mode proc all other flags are set as they were left by real-mode procedure real-mode register values are returned in the parameter block CF set on error EAX = error code 01h not enough real-mode stack space Note: unlike most of the preceding 25xxh functions, this one is not supported by FlashTek X-32VM SeeAlso: AX=250Eh,AX=250Fh Format of Phar Lap real-mode call parameter block: Offset Size Description (Table 01360) 00h WORD real-mode DS value 02h WORD real-mode ES value 04h WORD real-mode FS value 06h WORD real-mode GS value 08h DWORDDoubleword; four bytes. Commonly used to hold a 32-bit segment:offset or selector:offset address. real-mode EAX value 0Ch DWORDDoubleword; four bytes. Commonly used to hold a 32-bit segment:offset or selector:offset address. real-mode EBX value 10h DWORDDoubleword; four bytes. Commonly used to hold a 32-bit segment:offset or selector:offset address. real-mode ECX value 14h DWORDDoubleword; four bytes. Commonly used to hold a 32-bit segment:offset or selector:offset address. real-mode EDX value