Yamaha YIS-503IIR 1985 USSR version of the YIS-503II, targeted for schools. With network module (not emulated). MSX ru 807a823d4cac527c9f3758ed412aa2584c7f6d37 yis-503iir_basic-bios.rom 16000 ru false true true false V9938 16 YM2149 21000 true true