I have a Willem 5.0C EPROM burner with both the DIP42 and ADP-54 adapters. It took me awhile but I finally figured out how to burn 27C400 successfully. I burned several 27C400s and then my Willem 5.0C wouldn't burn them successfully. There is very little to no documentation on the web about the DIP42 and ADP-54 adapters. I tried everything and then started from scratch. I put the burner in "TEST" and check all my voltages. A14 was always 0v. I found that my 12 position DIP switch, switch 5 was bad. I replaced the DIP switches and all is good now. Both of those adapters you just put them in the Willem, put the EPROM at the bottom of the socket, and you are ready to read, burn and verify. When reading from a file, sometimes you have to do a "bit switch" or have it repeat at a certain address.
So the ROMs are on the 3.2CD? I have been holding off on upgrading to 3.2 because it is like $35 for the ROMs. If I can burn my own, cool!
Has anyone used 27C4000G EPROMS in an Amiga? If you compare datasheets between the 27C400 and the 27C4000 they look to be the same and both with 12.5v programming voltage. I have burn them successfully but not tried them in an Amiga yet. *** NOTE: I just watched the 3.2 ROM burning and it sounds like the guy doing it is already using the 27C4000 chip.