Question

what are the contents of the CS and IP registers immediately after the reset of the 8086?​

Answer 1

Answer:

sorry don't know....?.

Answer 2

CS and IP register immediately after the reset of 8086 is FFFF:0000.

Explanation:

• This value is the lowest 16bytes of memory.  

• In this location, there is a jump instruction to initialize the processor.

• The processor doesn't directly take CS:IP to 0000:0000.

• At 0000:0000 there is the Interrupt Vector Table (IVT) which handles the interrupts with an array possibly accessed by an extended call instruction in 8086-hardware.  

• At F000:FFF0 that are the last 16 bytes before 1 Megabyte or FFFF:0000, there is the cached copy of the motherboard BIOS-ROM in 8086-architecture going from F000:0000 to F000:FFFF.

• An illogical, but architecturally fixed, entry point into the initialization routines of the BIOS.

• Locating the BIOS address to 0000:0000 would confuse the circuits in the 8086-CPU for computing the address and calling interrupts with INT/IRET, which is very simple if the table is placed at zero.