In the past six years we have had to purchase two universal programmers and are now faced with having to purchase yet another.

Each of the manufacturers of our existing programmers claim "lifetime free software upgrades" but then announce a new model and stop supporting the older model. These are not cheap products - we paid about US$1000 for each.

In this instance we want to program the (relatively) new Phillips 87C51X2 One-Time-Programmable part. The summary data sheet shows the programming algorithms to be identical to the Phillis 87C51C but both our universal programmers baulk at programming the X2 chip. It's probable that the only difference is the chip ID. When we asked Phillips about any differences they declined to specify and suggested we "purchase a programmer that supported the X2 chip".

Apparently Phillips got tired of responding to people having problems with their home-made programmers so will no longer provide the specifics of how to program their new chips. The details are provided only to programmer manufacturers.

So be warned if you think you are purchasing a unniversal programmer that it will only be current for about 2-3 years.