Well, that is certainly a Yamaha drive. Also, since it doesn't say 3.3v, I'd presume it to be 5v. Plus, based on your statement of it being from 1998, I'd presume it to be a model 0 Dreamcast, which is where the 5v drives would normally be.
I'd stay away from interchanging drives between that console and any with 3.3v drives. The voltages won't be correct and will probably damage the drives (although, it may not be immediate). Heck, even the GD-ROM emulation devices won't work properly on those consoles, due to the difference in voltages (see here
for a statement from the creator of the original GDEMU on that).
Thanks for the pictures of the drive though, since I never got mine out of storage to take pictures of it.