// license:LGPL-2.1+ // copyright-holders:Tomasz Slanina /*************************************************************************** machine.c Functions to emulate general aspects of the machine (RAM, ROM, interrupts, I/O ports) ***************************************************************************/ #include "emu.h" #include "includes/nycaptor.h" READ8_MEMBER(nycaptor_state::nycaptor_68705_port_a_r) { return (m_port_a_out & m_ddr_a) | (m_port_a_in & ~m_ddr_a); } WRITE8_MEMBER(nycaptor_state::nycaptor_68705_port_a_w) { m_port_a_out = data; } WRITE8_MEMBER(nycaptor_state::nycaptor_68705_ddr_a_w) { m_ddr_a = data; } /* * Port B connections: * * all bits are logical 1 when read (+5V pullup) * * 1 W when 1->0, enables latch which brings the command from main CPU (read from port A) * 2 W when 0->1, copies port A to the latch for the main CPU */ READ8_MEMBER(nycaptor_state::nycaptor_68705_port_b_r) { return (m_port_b_out & m_ddr_b) | (m_port_b_in & ~m_ddr_b); } WRITE8_MEMBER(nycaptor_state::nycaptor_68705_port_b_w) { if (BIT(m_ddr_b, 1) && BIT(~data, 1) && BIT(m_port_b_out, 1)) { m_port_a_in = m_from_main; if (m_main_sent) m_mcu->set_input_line(0, CLEAR_LINE); m_main_sent = 0; } if (BIT(m_ddr_b, 2) && BIT(data, 2) && BIT(~m_port_b_out, 2)) { m_from_mcu = m_port_a_out; m_mcu_sent = 1; } m_port_b_out = data; } WRITE8_MEMBER(nycaptor_state::nycaptor_68705_ddr_b_w) { m_ddr_b = data; } READ8_MEMBER(nycaptor_state::nycaptor_68705_port_c_r) { m_port_c_in = 0; if (m_main_sent) m_port_c_in |= 0x01; if (!m_mcu_sent) m_port_c_in |= 0x02; return (m_port_c_out & m_ddr_c) | (m_port_c_in & ~m_ddr_c); } WRITE8_MEMBER(nycaptor_state::nycaptor_68705_port_c_w) { m_port_c_out = data; } WRITE8_MEMBER(nycaptor_state::nycaptor_68705_ddr_c_w) { m_ddr_c = data; } WRITE8_MEMBER(nycaptor_state::nycaptor_mcu_w) { m_from_main = data; m_main_sent = 1; m_mcu->set_input_line(0, ASSERT_LINE); } READ8_MEMBER(nycaptor_state::nycaptor_mcu_r) { m_mcu_sent = 0; return m_from_mcu; } READ8_MEMBER(nycaptor_state::nycaptor_mcu_status_r1) { /* bit 1 = when 1, mcu has sent data to the main cpu */ return m_mcu_sent ? 2 : 0; } READ8_MEMBER(nycaptor_state::nycaptor_mcu_status_r2) { /* bit 0 = when 1, mcu is ready to receive data from main cpu */ return m_main_sent ? 0 : 1; }