@@ -89,13 +89,13 @@
 # endif
 # if defined(__mc68010__) || defined(OF_M68020)
 #  define OF_M68010
 # endif
 # if defined(__riscv) && defined(__riscv_xlen) && __riscv_xlen == 64
-#  define OF_RISCV64
+#  define OF_RISC_V_64
 # elif defined(__riscv)
-#  define OF_RISCV
+#  define OF_RISC_V
 # endif
 #endif
 
 #if defined(__APPLE__)
 # include <TargetConditionals.h>
@@ -141,10 +141,12 @@
 #elif defined(_PSP)
 # define OF_PSP
 #elif defined(__DJGPP__)
 # define OF_DJGPP
 # define OF_MSDOS
+#elif defined(__riscos__)
+# define OF_ACORN_RISC_OS
 #endif
 
 #if defined(__ELF__)
 # define OF_ELF
 #elif defined(__MACH__)