asm(" push es"); /* save segment register */
asm(" mov ax, 034h"); /* use the Phar Lap Local Descriptor Table (LDT) */
asm(" mov es, ax"); /* segment selector 034h to access real memory */
ebx = addr; /* real memory address desired */
cl = val; /* byte value to poke */
asm(ebx, cl, " mov byte ptr es:[ebx], cl"); /* poke it */
asm(" pop es") /* restore segment register */