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Added just enough hopefully to allow implementation of the keyboard-input VIA.

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This commit is contained in:
Thomas Harte 2016-06-11 11:34:39 -04:00
parent de84758862
commit 7a241b5ef5
2 changed files with 25 additions and 10 deletions
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34
Components/6522/6522.hpp
View File

@ -40,13 +40,18 @@ template <class T> class MOS6522 {
{
case 0x00:
_registers.output[1] = value;
static_cast<T *>(this)->set_port_output(1, value); // TODO: handshake
break;
case 0x01:
_registers.output[0] = value;
static_cast<T *>(this)->set_port_output(0, value); // TODO: handshake
break;
case 0xf:
// No handshake, so write directly
_registers.output[0] = value;
static_cast<T *>(this)->set_port_output(0, value);
break;
case 0x02:
_registers.data_direction[1] = value;
break;
@ -104,11 +109,12 @@ template <class T> class MOS6522 {
// printf("6522 %p: %d\n", this, address);
switch(address)
{
case 0x00: return _registers.input[1];
case 0x01: return _registers.input[0];
case 0x00: return (_registers.auxiliary_control & 0x40) ? _registers.input[1] : static_cast<T *>(this)->get_port_input(1);
case 0x0f: // TODO: no handshake
case 0x01: return (_registers.auxiliary_control & 0x80) ? _registers.input[0] : static_cast<T *>(this)->get_port_input(0);
case 0x02: return _registers.data_direction[1];
case 0x03: return _registers.data_direction[0];
case 0x0f: return _registers.input[1];
// Timer 1
case 0x04:
@ -138,6 +144,10 @@ template <class T> class MOS6522 {
return 0xff;
}
void set_control_line_input(int port, int line, bool value)
{
}
void run_for_cycles(unsigned int number_of_cycles)
{
_registers.timer[0] -= number_of_cycles;
@ -157,9 +167,7 @@ template <class T> class MOS6522 {
// TODO: reload shouldn't occur for a further 1.5 cycles
if(_registers.auxiliary_control&0x40)
{
_registers.timer[0] = _registers.timer_latch[0];
}
else
_timer_is_running[0] = false;
}
@ -183,6 +191,12 @@ template <class T> class MOS6522 {
{}
private:
// Intended to be overwritten
uint8_t get_port_input(int port) { return 0xff; }
void set_port_output(int port, uint8_t value) {}
// Delegate and communications
MOS6522Delegate *_delegate;
bool _last_posted_interrupt_status;
inline void reevaluate_interrupts()
{
@ -194,8 +208,7 @@ template <class T> class MOS6522 {
}
}
MOS6522Delegate *_delegate;
// The registers
struct Registers {
uint8_t output[2], input[2], data_direction[2];
uint16_t timer[2], timer_latch[2];
@ -203,11 +216,14 @@ template <class T> class MOS6522 {
uint8_t auxiliary_control, peripheral_control;
uint8_t interrupt_flags, interrupt_enable;
// "A low reset (RES) input clears all R6522 internal registers to logic 0"
Registers() :
data_direction{0, 0},
interrupt_enable(0) {}
output{0, 0}, input{0, 0}, data_direction{0, 0},
auxiliary_control(0), peripheral_control(0),
interrupt_flags(0), interrupt_enable(0) {}
} _registers;
// Internal state other than the registers
bool _timer_is_running[2];
};

1
Machines/Vic-20/Vic20.cpp
View File

@ -85,7 +85,6 @@ unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uin
void Machine::mos6522_did_change_interrupt_status(void *mos6522)
{
bool irq = _userPortVIA->get_interrupt_line() || _keyboardVIA->get_interrupt_line();
printf("IRQ: %s\n", irq ? "e" : "-");
set_irq_line(irq);
}