To wrap it up,
I was able to program all three eeproms with original pc-bios and verify each. The pc would boot from all three of them.
The single requried change to the code was :
# svn diff Index: jedec.c =================================================================== --- jedec.c (wersja 2500) +++ jedec.c (kopia robocza) @@ -144,9 +144,11 @@ /* transfer data from source to destination */ for (i = 0; i < page_size; i++) { /* If the data is 0xFF, don't program it */ - if (*src == 0xFF) - continue; - *dst++ = *src++; + if (*src != 0xFF ) + *dst = *src; + dst++; + src++; + }
toggle_ready_jedec(dst - 1);