/*****************************************************************************
** apple1_kbd_poll
**
** Keyboard polling handles both ordinary keys and the special RESET
** and CLEAR SCREEN switches.
**
** For ordinary keys, this implements 2-key rollover to reduce the
** chance of missed keypresses. If we press a key and then press a
** second key while the first hasn't been completely released, as
** might happen during rapid typing, only the second key is
** registered; the first key is ignored.
**
** If multiple newly-pressed keys are found, the one closest to the
** end of the input ports list is counted; the others are ignored.
*****************************************************************************/
static void apple1_kbd_poll(int dummy)
{
int port, bit;
int key_pressed;
UINT32 shiftkeys, ctrlkeys;
/* This holds the values of all the input ports for ordinary keys
seen during the last scan. */
static UINT32 kbd_last_scan[] = { 0, 0, 0, 0 };
static int reset_flag = 0;
/* First we check the RESET and CLEAR SCREEN pushbutton switches. */
/* The RESET switch resets the CPU and the 6820 PIA. */
if (readinputport(5) & 0x0001)
{
if (!reset_flag) {
reset_flag = 1;
/* using PULSE_LINE does not allow us to press and hold key */
cpunum_set_input_line(0, INPUT_LINE_RESET, ASSERT_LINE);
pia_reset();
}
}
else if (reset_flag) {
/* RESET released--allow the processor to continue. */
reset_flag = 0;
cpunum_set_input_line(0, INPUT_LINE_RESET, CLEAR_LINE);
}
/* The CLEAR SCREEN switch clears the video hardware. */
if (readinputport(5) & 0x0002)
{
if (!apple1_vh_clrscrn_pressed)
{
/* Ignore further video writes, and clear the screen. */
apple1_vh_clrscrn_pressed = 1;
apple1_vh_dsp_clr();
}
}
else if (apple1_vh_clrscrn_pressed)
{
/* CLEAR SCREEN released--pay attention to video writes again. */
apple1_vh_clrscrn_pressed = 0;
}
/* Now we scan all the input ports for ordinary keys, recording
new keypresses while ignoring keys that were already pressed in
the last scan. */
apple1_kbd_data = 0;
key_pressed = 0;
/* The keyboard strobe line should always be low when a scan starts. */
pia_set_input_ca1(0, 0);
shiftkeys = readinputport(4) & 0x0003;
ctrlkeys = readinputport(4) & 0x000c;
for (port = 0; port < 4; port++)
{
UINT32 portval = readinputport(port);
UINT32 newkeys = portval & ~(kbd_last_scan[port]);
if (newkeys)
{
key_pressed = 1;
for (bit = 0; bit < 16; bit++) {
if (newkeys & 1)
{
apple1_kbd_data = (ctrlkeys)
? apple1_control_keymap[port*16 + bit]
: (shiftkeys)
? apple1_shifted_keymap[port*16 + bit]
: apple1_unshifted_keymap[port*16 + bit];
}
newkeys >>= 1;
}
}
kbd_last_scan[port] = portval;
}
if (key_pressed)
{
/* The keyboard will pulse its strobe line when a key is
pressed. A 10-usec pulse is typical. */
pia_set_input_ca1(0, 1);
timer_set(TIME_IN_USEC(10), 0, apple1_kbd_strobe_end);
}
}
/*****************************************************************************
** apple1_kbd_poll
**
** Keyboard polling handles both ordinary keys and the special RESET
** and CLEAR SCREEN switches.
**
** For ordinary keys, this implements 2-key rollover to reduce the
** chance of missed keypresses. If we press a key and then press a
** second key while the first hasn't been completely released, as
** might happen during rapid typing, only the second key is
** registered; the first key is ignored.
**
** If multiple newly-pressed keys are found, the one closest to the
** end of the input ports list is counted; the others are ignored.
*****************************************************************************/
static TIMER_CALLBACK(apple1_kbd_poll)
{
apple1_state *state = machine.driver_data<apple1_state>();
int port, bit;
int key_pressed;
UINT32 shiftkeys, ctrlkeys;
pia6821_device *pia = machine.device<pia6821_device>("pia");
static const char *const keynames[] = { "KEY0", "KEY1", "KEY2", "KEY3" };
/* This holds the values of all the input ports for ordinary keys
seen during the last scan. */
/* First we check the RESET and CLEAR SCREEN pushbutton switches. */
/* The RESET switch resets the CPU and the 6820 PIA. */
if (input_port_read(machine, "KEY5") & 0x0001)
{
if (!state->m_reset_flag) {
state->m_reset_flag = 1;
/* using PULSE_LINE does not allow us to press and hold key */
cputag_set_input_line(machine, "maincpu", INPUT_LINE_RESET, ASSERT_LINE);
pia->reset();
}
}
else if (state->m_reset_flag) {
/* RESET released--allow the processor to continue. */
state->m_reset_flag = 0;
cputag_set_input_line(machine, "maincpu", INPUT_LINE_RESET, CLEAR_LINE);
}
/* The CLEAR SCREEN switch clears the video hardware. */
if (input_port_read(machine, "KEY5") & 0x0002)
{
if (!state->m_vh_clrscrn_pressed)
{
/* Ignore further video writes, and clear the screen. */
state->m_vh_clrscrn_pressed = 1;
apple1_vh_dsp_clr(machine);
}
}
else if (state->m_vh_clrscrn_pressed)
{
/* CLEAR SCREEN released--pay attention to video writes again. */
state->m_vh_clrscrn_pressed = 0;
}
/* Now we scan all the input ports for ordinary keys, recording
new keypresses while ignoring keys that were already pressed in
the last scan. */
state->m_kbd_data = 0;
key_pressed = 0;
/* The keyboard strobe line should always be low when a scan starts. */
pia->ca1_w(0);
shiftkeys = input_port_read(machine, "KEY4") & 0x0003;
ctrlkeys = input_port_read(machine, "KEY4") & 0x000c;
for (port = 0; port < 4; port++)
{
UINT32 portval, newkeys;
portval = input_port_read(machine, keynames[port]);
newkeys = portval & ~(state->m_kbd_last_scan[port]);
if (newkeys)
{
key_pressed = 1;
for (bit = 0; bit < 16; bit++) {
if (newkeys & 1)
{
state->m_kbd_data = (ctrlkeys)
? apple1_control_keymap[port*16 + bit]
: (shiftkeys)
? apple1_shifted_keymap[port*16 + bit]
: apple1_unshifted_keymap[port*16 + bit];
}
newkeys >>= 1;
}
}
state->m_kbd_last_scan[port] = portval;
}
if (key_pressed)
{
/* The keyboard will pulse its strobe line when a key is
pressed. A 10-usec pulse is typical. */
pia->ca1_w(1);
machine.scheduler().timer_set(attotime::from_usec(10), FUNC(apple1_kbd_strobe_end));
}
}
void apple1_state::machine_reset()
{
/* Reset the display hardware. */
apple1_vh_dsp_clr(machine());
}