//
// EMULATION FOR MICROTAN 65 ON NEO6502 SBC
//
// Neo6502 SBC @ https://www.olimex.com/Products/Retro-Computers/Neo6502/open-source-hardware
//
// Neo6502 has "real" 65C02 with Pi Pico providing all RAM, "ROM", clocking and peripheral interfaces
// Includes USB keyboard and DVI/HDMI video
//
// This program is intended to load and run original Microtan 65 code (e.g. Tanbug monitor) unchanged.
// Memory accesses are "captured" and simulated by the Pi Pico, including memory mapped I/O
// Display is emulated by Pi Pico from Microtan 65 video memory
//
// In addition to the actual emulation, this code provides a basic "monitor"-like interface to load
// program data, activate the 6502, etc
//
// Microtan 65 memory map:
//   $0000          Zero page
//   $0100          Stack
//   $0200 / $300   Screen RAM
//   $8000          I/O page ???
//   $F800 - $FFFF  Tanbug Monitor
//

//
// TODO LIST
//   - Create custom chip for 74VC245 tri-state bus transceiver
//   - Borrow Wokwi 65C02 custom chip (e.g. mega6502 @ https://wokwi.com/projects/357113701134775297)
//   - Simulate Neo6502 hardware in Wokwi
//   - Develop additional code here
//

#include <stdio.h>
#include <string.h>
#include "pico/stdlib.h"
#include "hardware/gpio.h"

#include "cpu6502.h"
#include "cpu6502_mem.h"
#include "mon_parse.h"
#include "mon_cmds.h"

//
// INIT
//

void init() {
  stdio_init_all();
  printf("Neo6502\nEmulating the Microtan 65 (v0.1)\n\n");
}


//
// LOOK AT COMMAND LINE ENTERED
//

// TODO : make this non-blocking : check character available on input, if not return ?

void parse_line() {
  printf(">");    // Output prompt

  if (get_line_uppercase()) {

    int parameter;
    int item_type = get_item_from_line(&parameter);

    switch (item_type) {
      case IT_COMMAND:
        mon_cmds_do(parameter);         // Parameter = keyword ID
        break;

      case IT_NUMBER:
        mon_cmds_wozmon(parameter);     // Parameter = number value
        break;

      default:
        printf("Unknown command\n");
        break;
    }
  }
}


//
// MAIN
//

int main() {
  init();
  while (true) {
    parse_line();
  }
}