16f877 ain't giving me any lovin'

I have been trying to flash a 16f877 in order to build some of Tom Scarff's fantastic-looking MIDI hardware. But it always fails to verify correctly! I really need to narrow down whether it is the programmer or the chip (might be the latter, as I picked it up really cheap). I have heard that some serial ports can't achieve high enough voltages to program a chip such as the 16f877. The problem is I only have one chip, so it makes things a little more complicated... oh well...