Hello z80 with arduino

Projects General Guidance
16

//
// This sketch uses code on the Z80 to write a greeting to the serial-console.
//
// We let this program run for a few thousand cycles, which should be
// sufficient to allow the text-output, "Hello\n", to complete.
//
// Steve
//

#include <z80retroshield.h>

//
// Our program, as hex.
//
// The source code is located in hello.z80.
//
unsigned char memory[32] =
{
0x3e, 0x48, 0xd3, 0x01, 0x3e, 0x65, 0xd3, 0x01, 0x3e, 0x6c, 0xd3, 0x01,
0xd3, 0x01, 0x3e, 0x6f, 0xd3, 0x01, 0x3e, 0x0a, 0xd3, 0x01, 0xc3, 0x16,
0x00
};
int memory_len = sizeof(memory) / sizeof(memory[0]);

//
// Our helper
//
Z80RetroShield cpu;

//
// RAM I/O function handler.
//
char memory_read(int address)
{
return (memory[address]);
}

//
// I/O function handler.
//
void io_write(int address, char byte)
{
if (address == 1)
Serial.write(byte);
}

//
// Setup routine: Called once.
//
void setup()
{
Serial.begin(115200);

//
// Setup callbacks.
//
// We must setup a memory-read callback, otherwise the program
// won't be fetched and executed.
//
cpu.set_memory_read(memory_read);

//
// Then we setup a callback to be executed every time an "out (x),y"
// instruction is encountered.
//
cpu.set_io_write(io_write);

//
// Configured.
//
Serial.println("Z80 configured; launching program.");

}

//
// Loop function: Called forever.
//
void loop()
{
//
// We stop running after a specific number of cycles
//
// Have we reached that point?
//
static bool done = false;

//
// Count the number of times we've pumped the Z80.
//
static int cycles = 0;

//
// Are we done?  If so return.
//
if (done)
    return;

//
// We stop running after running a specific number of cycles
//
if (cycles > 4096)
{
    Serial.print("Z80 processor stopped ");
    Serial.print(cycles);
    Serial.println(" cycles executed.");
    done = true;
    return;
}

//
// Step the CPU.
//
cpu.Tick();

//
// We've run a tick.
//
cycles++;

}