In my infinite wisdom, I'm formulating Waferboard to Particleboard! For your benefit, if you have OSB, you're probably OK. (Again, I'd check w/the mfgr. to see what they say TO BE SURE you don't Void the Warranty.) I could say you're OK but it may NOT be OK.
Particleboard will 'chip' when nailed and/or screwed, and over time, they will come 'loose' from movement. Waferboard is a predacesor (sp) of OSB. For some more info, check out these links:
I can't say for sure what you have. Your OSB 'may' look like wafferboard but it 'may' be particleboard, and so on. If you can get to a heat vent or a doorway (where you can remove a threshold or 'transition strip', take a look at the SIDE of the sheathing. Make a mental picture of that as well as a mental picture of the TOP of the sheathing. From there, go back to Home Depot and see if you can find the same thing. I'm a bit confused by the info you just gave me. In the first stmt., you said that HD has the same underlayment as your dining room. Then, in the next sentence, you say the underlayment looks like the description I gave (pieces or chips of wood glued together.) OSB is clearly distince from Wafferboard. Really, I'm a little afraid to say what I think you have. It could be either/or.
Jay J -Moderator
PS: If you have OSB, before you rip it up, just check w/the mfgr. to see if it's OK. If not, go w/their advice.