Silly question, just out of curiosity.
I know there is an 'A' and 'S' firmware, but have not seen an example of DVD 'S' in any of the posted scans, maybe someone really smart can help me...
All Write. My 20A4H use "S" firmware and it shows as ATAPI DVD A DH20A4H.
OK, makes sense.
Other drives show "DVDRW" because they don't burn DVD-RAM, but this write "all" formats, hence it's trade name.
OK, thanks juancdg
The 'A' and 'S' firmwares are tweaks for the particular laser diodes in the A4-series, since probably during the manufacturing process, the supplier had changed. There is no correlation of the 'A' in the ID with respect to firmware versions.