Sorry, I am a newbie and can not fix the problem,So...

I made my own isp cable with the help of picture here:
http://www.21icbbs.com/club/bbs/...&ID=593835
they said that the cable works well under ATMEL ISP sofware and AEC_isp, but my cable can not work :(

when I try to use my cable under atmel_isp software, the target can be initialized well.But AT89S52 in the board usually can not be read, when the chip was read, the software said that it is bit locked, and the chip can not be erased either, when the chip was erased, the error message is "Unable comminucate with the device,Please check the cable connection,ensure that the device is on, and reinitialize the device"

when I use my cable under aec_isp software, the chip can be read and erased but can not be programmed normally, when it is programmed, the error message is " error while programming flash memory","Flash byte error in address 0000".
After I read the flash of the chip,all the flash buffer is "FF", then the chip can be wrote, namely Only the "FF" can be wrote into flash.

Any help will be appreciated!