I use that software version : (
) with the "true usb willem programmer" a new version of the well known willem, which uses usb in replacement of the parallel.
you have the url in the pic for more infos. a cool new function is "byte swap" (no need for winhex) :-)
The 27C400 is in the "supported devices" list and need the "16 bit eprom adaptator", I've bought the zif socket version with the programmer.
by editing the devices.dat file I've found the 27C400 entry and succeeded to make it appears in the device list. but all chip I give to it's "blank test" says the same : not blank (even with new ones!) and trying to read a (known full and fonctionning) chip read something but the data does not appear in the buffer window. ???