However, it is far more complicated than modern ISP schemes that require just a serial port; eg, the 89LPC932.
which is why I have stated several times "use an ISP chip" what reason can there be to use an older chip?

For the P89LPC932 you will either need to istall some rather complicated logic or implement the NoTouch for LPC932 in my user page. The LPC932 will, fresh from the factory program without any special stuff, from then on you need a chip and a few other things to do it BUT ONLY IF you do not implement NoTouch.

For that reason I suggest tha first ISP experience to be with chips such as the P89C51Rx2 or P89C66x.

Erik