Programming an ancient 1970's Intel 8751H with TL866 FAIL. DON'T DO THIS!

This video was going to be an instruction video on how to program the original, "vanilla" vintage Intel P8751H microcontrollers which I had already successfully erased with UV light. But it turned into a disaster with a ruined chip. I thought I'd release it anyway so others do not fall into the same trap I did assuming this would work. Assumptions are the mother of all F**kups right? Yeah...

Maybe I did something wrong? Who knows.

So back to the story. When it came to programming I found that the TL866 only supports the CMOS version (87C51) which has a programming voltage of 12.5V. The older chips like in this example need 21V which the TL866-2 does not support and even if it did the algorithm is set to 12.5V.

So isolating the VPP pin and applying 21V to it from an external power supply should work right? Well apparently not. ... https://www.youtube.com/watch?v=t3qJT_9tZCY