Speaking of which here is the FUSE sinclair zx spectrum emulator, recompiled in the stable retroarch branch
If controls do not work (which they wont at first): Load ROM>RetroArch Quick Menu>Controls>User 1 Device Type>Set to whatever joystick the game is asking you for. An on screen keyboard, atleast for the kempston joystick, is bound to select (-)
Many very thanks, it exists any new version? when you change to another rom, switch hangs.