Hi Hrishikesh B
The programmer you built was designed by M.Asimkhan and someone had succeded in building one. The reason you got shocked is this: the power supply of all computer has some capacitor of about 10nF connect from hot side of ac source to the chassis ground therefore you HAVE to ground your computer’s case for safety’s sake
Mr Wichit is very helpful he does not elaborate but his answers are very courteous and effective, when I first start out with MCU, I built the Easy down loader V2.0 he designed using PCB file from Bruno Macio(single side pcb) it did not work first try,he gently gave me a lot of advices till I found out the problem(my fault)this gave me the courage to build his SBC which he called C52EVB.I designed the single sided pcb based on his schematic it works on the first try(I can give you this pcb file if you’re using Protel).I can tell you this, Wichit’s sources are very reliable therefore check and double check your work then you might find the problem or if you can have access to a programmer try building the simpler V2.0
Good luck
Vu Nhu Khanh