Int 15 Fn 87  - System - Copy Extended Memory                              [B]

   AH = 87h
   CX = number of words to copy (max 8000h)
   ES:SI -> global descriptor table (see #0425)

Return: CF set on error
   CF clear if successful
   AH = status (see #0424)

Notes: copy is done in protected mode with interrupts disabled by the default
     BIOS handler; many 386 memory managers perform the copy with
     interrupts enabled
   this function is incompatible with the OS/2 compatibility box

See Also: AH=88h,AH=89h,INT 1F/AH=90h

(Table 0424)
Values for extended-memory copy status:
 00h   source copied into destination
 01h   parity error
 02h   interrupt error
 03h   address line 20 gating failed
 80h   invalid command (PC,PCjr)
 86h   unsupported function (XT,PS30)

Format of global descriptor table:
Offset Size    Description (Table 0425)
 00h 16 BYTEs  zeros (used by BIOS)
 10h   WORD    source segment length in bytes (2*CX-1 or greater)
 12h  3 BYTEs  24-bit linear source address, low byte first
 15h   BYTE    source segment access rights (93h)
 16h   WORD    (286) zero
       (386+) extended access rights and high byte of source address
 18h   WORD    destination segment length in bytes (2*CX-1 or greater)
 1Ah  3 BYTEs  24-bit linear destination address, low byte first
 1Dh   BYTE    destination segment access rights (93h)
 1Eh   WORD    (286) zero
       (386+) extended access rights and high byte of destin. address
 20h 16 BYTEs  zeros (used by BIOS to build CS and SS descriptors)