I bought a used Dell TS-L632D to replace the combo drive in my Acer Aspire 5315. I looked up the specs and figured it’d be a good one because not only did it say dual layer, dual format but also DVD-RAM. ('Course I didn’t see the DELL specifications…)
When Nero Info Tool showed no DVD-R DL support or DVD-RAM I went firmware hunting.
The drive now has RPC1 Toshiba/Samsung SC04 firmware and supports -R dual layer and DVD-RAM. (Now I just need some affordable dual layer media and a DVD-RAM disk to try!)