SCPE_NXREG 3383 src/simh/scp.c return SCPE_NXREG; SCPE_NXREG 6104 src/simh/scp.c return SCPE_NXREG; SCPE_NXREG 6120 src/simh/scp.c return SCPE_NXREG;