Need help programming 16F877

I am trying to program a 16F877 from a hex file using my P16PRO parallel port programmer. I can't get it to program with either ICProg or Picallw software, and I checked that I have the latest versions. Code protect is shown as off when I open the hex file. I know my programmer works because I used to use ICProg all the time to program 12F629s. I just downloaded WinPicProg 1.91 but do not know which options to set for a P16PRO programmer, so I have not tried it yet. Any ideas as to what my problem may be?

Try pulling PGM (RB3) to ground with a resistor. Is the LVP fuse disabled?

Maybe this is also a stupid question, but which direction does the 40-pin PIC mount to the P16PRO40? It indicates which end pin 1 goes to for 8, 18, and 28 pin PICS. I just tried to program again this morning using WinPicProg with no luck.

Low voltage is not checked.

I also tried using the resistor between ground and RB3, with no luck.

The error message is "Program Verify failed at address 0x000. Programming aborted."

Pin 1 on all PIC's point the same way, toward the lever on the ZIF socket. That error message is commonly caused by a poor power supply, either too low, or too much ripple.

My P16PRO40 has the individual sockets, not the ZIF. I will change my power supply and try again, but this one used to work. I am only at 18.3VDC.

kittydog42 said:

My P16PRO40 has the individual sockets, not the ZIF. I will change my power supply and try again, but this one used to work. I am only at 18.3VDC.

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Is it a regulated supply?.

Can you still program 629s?

Mike.