Some newer Seagate drives like 7200.12 and 7200.14 will use a 1.8V SPI flash to store the ROM code.
The Willem programmer can't program at a lower voltage than 3.6V, so it will not by itself support 1.8V chips and attempting to read/write a 1.8V chip on the Willem might even kill the chip.
A solution for it is to use a 1.8V SPI Flash base adapter. This is confirmed to work.
Unfortunately at the moment I can't find any place that sell those, so the only option (unless someone knows of a place selling those adaptors) is to made your own.
Another option is to buy a programmer that supports 1.8V SOIC8 SPI Flash chips.
For doing the adaptor for Willem here are the diagram and photos. Hope this can be useful to someone looking for a cheap alternative to program 1.8V SPI Flash chips :