yeah..parallel port is working well..else the software reports an error..
all the connections are made on PCB..so no loose connections..
does the absence of buffer IC making a trouble..?
yeah..parallel port is working well..else the software reports an error..
all the connections are made on PCB..so no loose connections..
does the absence of buffer IC making a trouble..?
check loop between pin40 and pin31
have a 10n cap across power supply
use only 4MHz crystal with 33p caps on either side
have 47 ohm resistors in series on sck, mosi and miso wires , with a 47pF to ground from each at the 89S5X pins.
connect the pc ground (body) to the gnd common or pin20 of 89S5x, the programmer should work.
dont tamper the fuse bits
if already done changes , reset them using any high voltage 12V Vpp, parallel port programer.
two issues reformed-
1.) DB25 cable length was cut shortened to 12cm (thanks to hewitson)
2.)the PC with which i was using the software was getting a power supply from a port with not proper GROUND.
( generally people have their supply ports at homes without proper GROUND). Thus i gave supply to PC from a different port having proper GROUND.