Which calculators run RPL under the hood?

[Dave Britten]

Obviously the 48/49/50 line is built on RPL, and HP even made it available to users via both SysRPL and UserRPL, but it wasn't user-accessible at first.

18C - The first place it appeared
19B, 19BII
28C, 28S - UserRPL programming, limited SysRPL access through SYSEVAL
17B
17BII
27S
42S
48, 49, 50 - UserRPL and SysRPL
38, 39, 40 - These are all built on RPL, aren't they?

I think all the "high-end" Pioneers use RPL internally. What about the mid-range Pioneers like the 32S, 32SII, 14B, etc.? And I doubt the low-end models - 10B, 20S, 21S - use it.