At one point I started using SDCC (free C compiler) for 8052 stuff. I had a development board with an Atmel AT89S8252. Very short SDCC programs would work, but the longer ones would not. I found that the programmer was designed for .hex files, but that SDCC produces .ihx which is similar but not the same. I found a program that would convert and that solved the problem. But, in my case the verify always worked (yeah strange I know) but the program would not run for the longer files. It sounds like you may have a different problem since your verify does not work either.

How repeatable is the problem? In other words, do the files that work do so no matter how many times you try them? And the ones that don't work will not work no matter how many times you try them? Are the files that work longer or shorter than the ones that don't? Or is it that maybe the programmer only works sometimes regardless of the file?

Frank Kienast