void fastinvaders_state::fastinvaders_6845(machine_config &config) { fastinvaders(config); m_maincpu->set_addrmap(AS_IO, &fastinvaders_state::fastinvaders_6845_io); MC6845(config, m_crtc6845, 11500000/16); /* confirmed */ m_crtc6845->set_screen("screen"); m_crtc6845->set_show_border_area(false); m_crtc6845->set_char_width(16); m_crtc6845->out_vsync_callback().set(FUNC(fastinvaders_state::vsync)); m_crtc6845->out_hsync_callback().set(FUNC(fastinvaders_state::hsync)); }