The original RASP model of Elgot and Robinson had only three instructions in the fashion of the register-machine model, but they placed them in the register space together with their data. (Here COPY takes the place of CLEAR when one register e.g.
The initial RASP model by Elgot and Robinson featured just three instructions, mirroring the register-machine model, yet they integrated these instructions with their data within the register space.  (In this instance, COPY replaces CLEAR when a specific register is involved).