I have made this JDM pic programmer. but I don`t know the serial cable that I should use, cross, or direct ???
the programmer image and schematic are below :--
Instructables isn't much use. They are always vague and I hate how they want you to pay for information that you can get for free. You might do better to google for jdm programmers and find a better writeup. I know this isn't much help. here's another one.
Well, for 30+ years I always tried what I thought it should be and then crossed if it didn't work. Never had a problem. But not long ago I bought a RS232 level shifter from Polulu and it failed to work. Their support folks say I fried it from tying Tx to Tx. I don't believe that, but I now modify my advice to say trying connecting the pin you think is Tx to what you are sure is Rx and verify the connection by looking for data.