; BBC Micro OS ABI FSCV = &21E GBPBV = &21A BGETV = &216 FILEV = &212 WRCHV = &20E BYTEV = &20A IRQ2V = &206 IRQ1V = &204 BRKV = &202 USERV = &200 OSRDRM = &FFB9 OSEVEN = &FFBF GSINIT = &FFC2 GSREAD = &FFC5 NVRDCH = &FFC8 NVWRCH = &FFCB OSFIND = &FFCE OSBPUT = &FFD4 OSBGET = &FFD7 OSARGS = &FFDA OSFILE = &FFDD OSRDCH = &FFE0 OSASCI = &FFE3 OSNEWL = &FFE7 OSWRCH = &FFEE OSWORD = &FFF1 OSBYTE = &FFF4 OSCLI = &FFF7