error in ISP ???

[bhanot.manik90]

Guys, I need your help, I have made an ISP programmer for programming AT89S52 with the help from Asim khan's website. But when I WRITE a program , the software gives me the following error :
Program Verify Error @Address 0000
Data Read = 00
Prog Data = C2

So I simply can't understand this error. On the other hand, the software is able to read data from the microcontroller but as I have said already I am not able to write data into it???

PLEASE help me in sorting out this problem....

THANK YOU

 

[mvs sarma]

Check whether, the MOSI and MISO pins might be reversed. Secondly see whether the Reset cap is leaky.
the EA*pin is expected to be connected to Vdd
you are expected to use Fig2 of link below

**broken link removed**

Inside the Fig2, there is a note indicating that at DB25 connector pins2 and 12 must be looped. A crystal is to be used instead of 3 pin resonator and with 22pF cap grounded from each pin of the crystal.

connect the body of the DB25 to the ground of the programmer.

 

[johnsmith123]

build this one
**broken link removed**
it works with a serial port and is more reliable