The chip you are programming/debugging is know as the target chip or target for short.

The MCLR is a line used to set/reset the target, also provides the VPP program voltage.

The other two lines are serial lines used to communicate between the ICD2 and the target. PGD is program data and PGC is a clock line for use with PGD.

The ICD2 (and clones) is used with MPLAB software from Microchip. It is a IDE or Integrated Development Environment that also contains a PIC simulator program. MPLAB is the only free program that I know of that works with an ICD2. You can read more about MPLAB on the Microchip web site.

The inchworm and inchworm+ are ICD2 clones. You can find the schematics for building them at www.blueroomelectronics.com. Many here have built these from scratch or as kits.

Originally Posted by Suraj143

Here I have attached an ICD circuit one has already made.

Now if I want to program a new PIC16F876 where do I have to insert the chip? In the circuit already there is a 876 PIC.

I can plug the RS232 cable into this circuit. After that can I program with IC Prog?

The only program you can use with your ICD is MPLAB from Microchp. You can download it for free from the Microchip Website.

Your ICD uses an ICSP connector. It has the MCLR, PGD, PGC, +5 and GND pins. Take a look at the schematics you built it from. It is up to you to get these signals to your target chip. Most often we put an ICSP connector on the target board and use a cable to connect the ICD ICSP to the target ICSP. This saves having to move the chip to and from a programmer socket.

EDIT:
Did you build this ICD? If so I am not sure that you understand it. The ICD has a PIC on it that is used to program other PICs. The problem is that the onboard PIC needs to be programmed or the ICD will not work. So if this is your only programmer you have no way to programm the onboard PIC.

That is to say: The PIC on the ICD is part of the ICD and not a target for your use. It is the brains for the ICD.

Did you use a new/blank PIC in the ICD or has it been programmed for use with the ICD?

Originally Posted by Suraj143

Do I need two PICs?

Yes

While you were reading my last post I edited it. Please re read it.

It looks like your ICD uses a 16F876. This page has a link to the HEX file you need to program it with.

Where did you get the schematic for the one you built. Did it not talk about programming and testing the ICD?

Yes you need a different (simpler) programmer to program the PIC for the ICD.

One of the parallel types seem to be the most reliable. Some have had good luck with the JDM style programmers but not always with laptops.
You may want to go to the WinPicProg website and build the P16PRO40 programmer.

On stolz's site you need to see 3.1. ICD's Firmware.

He also has a low voltage programming cable that you can use to program the PIC.

It can be bult with only 4 10K resistors. He calls it dirty but working. The P16PRO40 is a better programmer but since you only need to program the one chp you may want to give it a try. I have not tried it.

I do not mind answering your questions but if you want better/faster answers to the simple ones you can google for them or look them up on wikipedia.

What follows have been put in the most basic terms. Not 100% correct but it should move you in the direction of understanding these terms enough so you can read more about them elsewhere.

First some basic definitions.

uC = microController
RAM = Random Access Memory
ROM = Read Only Memory
Flash = a type of ROM used by many uC, also known as EEPROM.

FIRMWARE is code that is saved in and executed out of ROM. Code you store/execute on a flash PIC is firmware. The code inside a microwave oven is firmware.

A BOOTLOADER is a simple program with the purpose to load other programs. A bootloader must be written to the uC with a programmer. After the bootloader is in place the uC can be programmed without the use of a programmer. Most often this is done over a RS232 or USB connection. The bootloader can also be used to reprogram the flash. So once you have a bootloader on a uC you can do without a programmer. This is very useful to upgrade firmware after a product is released.

A BOOTLOADER is most often firmware because it is software stored in ROM.

What does this mean for the ICD2?

The uC that is the brains of the ICD2 needs firmware to function.
To make life easy that firmware is initialy a bootloader.
MPLAB communicates with the bootloader on the ICD2 to download the software needed to program other PICs. Microchip calls this software an OS (operation system).

There are several OS used to program various Microchip uC's. If you had been programming 16F chps and switched to a 18F chip the ICD2 would need a different OS. MPLAB uses the bootloader on the ICD2 to load in that new OS.

HTH