// license:BSD-3-Clause // copyright-holders:R. Belmont /********************************************************************** General Instruments AY-5-3600 Keyboard Encoder emulation *********************************************************************/ /* TODO: - scan timer clock frequency - more accurate emulation of real chip */ #include "emu.h" #include "kb3600.h" //#define VERBOSE 1 #include "logmacro.h" //************************************************************************** // GLOBAL VARIABLES //************************************************************************** // devices DEFINE_DEVICE_TYPE(AY3600, ay3600_device, "ay3600", "AY-5-3600 Keyboard Encoder") //************************************************************************** // LIVE DEVICE //************************************************************************** //------------------------------------------------- // ay3600_device - constructor //------------------------------------------------- ay3600_device::ay3600_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : device_t(mconfig, AY3600, tag, owner, clock), m_read_x0(*this, 0), m_read_x1(*this, 0), m_read_x2(*this, 0), m_read_x3(*this, 0), m_read_x4(*this, 0), m_read_x5(*this, 0), m_read_x6(*this, 0), m_read_x7(*this, 0), m_read_x8(*this, 0), m_read_shift(*this, 0), m_read_control(*this, 0), m_write_data_ready(*this), m_write_ako(*this) { for (auto & elem : m_x_mask) { elem = 0; } } //------------------------------------------------- // device_start - device-specific startup //------------------------------------------------- void ay3600_device::device_start() { // allocate timers m_scan_timer = timer_alloc(FUNC(ay3600_device::perform_scan), this); m_scan_timer->adjust(attotime::from_hz(60), 0, attotime::from_hz(60)); m_ako = 0; // state saving save_item(NAME(m_b)); save_item(NAME(m_ako)); save_item(NAME(m_x_mask)); } //------------------------------------------------- // device_start - device-specific reset //------------------------------------------------- void ay3600_device::device_reset() { } //------------------------------------------------- // perform_scan - scan the keyboard matrix //------------------------------------------------- TIMER_CALLBACK_MEMBER(ay3600_device::perform_scan) { int ako = 0; for (int x = 0; x < 9; x++) { uint16_t data = 0; switch(x) { case 0: data = m_read_x0(); break; case 1: data = m_read_x1(); break; case 2: data = m_read_x2(); break; case 3: data = m_read_x3(); break; case 4: data = m_read_x4(); break; case 5: data = m_read_x5(); break; case 6: data = m_read_x6(); break; case 7: data = m_read_x7(); break; case 8: data = m_read_x8(); break; } for (int y = 0; y < 10; y++) { int b = (x * 10) + y; if (b > 63) { b -= 64; b = 0x100 | b; } b |= (m_read_shift() << 6); b |= (m_read_control() << 7); if (BIT(data, y)) { ako = 1; if (!(m_x_mask[x] & (1 << y))) { m_x_mask[x] |= (1 << y); if (m_b != b) { m_b = b; m_write_data_ready(1); if (ako != m_ako) { m_write_ako(ako); m_ako = ako; } return; } } } else // key released, unmark it from the "down" info { m_x_mask[x] &= ~(1 << y); } } } if (!ako) { m_b = -1; } if (ako != m_ako) { m_write_ako(ako); m_ako = ako; } } //------------------------------------------------- // b_r - //------------------------------------------------- uint16_t ay3600_device::b_r() { uint16_t data = m_b; m_write_data_ready(0); return data; }