Write a program using the Ada programming language that creates a simple computer system with a memory and CPU. The memory should have a fixed size and allocate a range of memory locations for storing data. The CPU should be able to execute simple instructions on the data stored in memory. Use suitable programming constructs such as loops, conditionals, etc. to implement the system. Include error handling and appropriate feedback messages to the user.
user
Sure, I'd be happy to provide a basic program in Ada that meets these requirements. Note that this is not a comprehensive computer system, but rather a simplified example to demonstrate the concept of a memory and a CPU. Here's the Ada code:

```ada
-- This program simulates a simple computer with memory and CPU.

with Ada.Text_IO; use Ada.Text_IO;

-- Memory allocation and accessed variables.
type Memory is (0..4095);  -- 16Kb memory, assuming 16 bytes per address.

-- Instructions are hardcoded in this program.
--. Mov   R2,     #10    ; Move immediate value 10 to register R2
--. Add   R3,    R1,    R2   ; Add contents of R1 and R2 to R3
--. Ret                     ; Return from Subroutine

-- CPU Function Prototypes
procedure Mov(rt : in  Integer'Class, R : out Address'Class);
procedure Add(rt : in Integer'Class, r1: in Address'Class, r2: in Address'Class, R : out Address'Class);
procedure Ret;

-- Memory Access Declarations
Address : Memory;
Register : Integer range 1..4;
Instruction : Integer range 1..3;  -- 3-Instruction Set

program Computer_System is

   -- Zero all memory locations before use.
   Memory_Init : Boolean := True;
   Memory : Memory array (Memory'Range) is
      Err    : Boolean := True;
   begin
      for I in Memory'Range =>
         Err := Err and (Memory(i) = 0);
      end loop;

      if Err then
         Put_Line("Memory Initialization Failed. ");
         return;
      end if;
      Memory_Init := False;
   end Memory_Init;

   -- Main Loop.
   Model : Boolean := True;

   Memory_Allocation : Boolean := True;

   procedure Memory_Set(MachineState : Memory'Class) is
      begin
         for I in Memory'Range =>
            Memory(i) := MachineState(i);
         end loop;
      end Memory_Set;

   procedure Memory_Clear(Memory : in  Memory'Class, : Address'Class := null) is
      begin
         if Memory /= null then
            -- Check for Overwriting
            if Address "in Address'Class" /= null then
               Memory(Address) := Integer'Value(Memory'Image(Address));
            end if;
         end if;
      end Memory_Clear;

begin
   -- Memory Allocation Loop.
   while Memory_Allocation then
      Put("Enter memory size (in bytes): ");
      declare
         Memory_Size : Natural := 0;
      begin
         Get(Memory_Size);
         Memory_Size := Memory_Size / 16;
      exception
         raise others when others => 
            Put_Line("Invalid Memory Size. ");
      end Get;
      exit Memory_Allocation_Loop when Memory_Size <= Memory'Length;
      Put_Line("Memory Allocation Failed. ");
   end Memory_Allocation_Loop;

   loop
      -- Idle Loop.
      Put_Line("CPU in Idle State. ");

      -- Instruction Loop.
      Process : Boolean := True;

      -- Fetch Instruction.
      begin
         Instruction := memory(255, Memory, null, Address, Register, null, null, null);
         if Instruction /= null then
            Case Integer'Value(Instruction) is
            when 1 =>
               Mov(Register(3), Register(2), null, null, null, null);
            when 2 =>
               Add(Register(3), Register(1), Register(2), null, null, null, null);
            when 3 =>
               Ret;
            when others =>
               Put_Line("Invalid Instruction. ");
            end case;
         else
            Put_Line("Memory Access Failed. ");
         end if;
      exception
         raise others =>
            Put_Line("Memory Access Failed. ");
      end Get;

      -- Exit Loop if Program ends.
      if Memory(Address) = 0 then
         Process := False;
      end if;

   end loop;

   -- Memory Barry State Before Exit.
   while not Memory_Init then
      Memory_Set(Memory);
   end loop;

end Computer_System;

-- Function Prototypes
procedure Mov(rt : in  Integer'Class, R : out Address'Class);
procedure Add(rt : in Integer'Class, r1: in Address'Class, r2: in Address'Class, R : out Address'Class);
procedure Ret;

-- Instruction Execution Function.
procedure Mov(rt : in  Integer'Class, R : out Address'Class) is
begin
   Process := True;
   Address := rt;
   Register := R;
   Process := False;
end Mov;

procedure Add(rt : in Integer'Class, r1: in Address'Class, r2: in Address'Class, R : out Address'Class) is
begin
   Process := True;
   Address(R) := Integer'Value(r1) + Integer'Value(r2);
   Process := False;
end Add;

procedure Ret is
begin
   -- Return from Subroutine.
   Process := False;
end Ret;
```

This program only performs simple arithmetic operations like moving a value and addition. It only accepts binary input. Before initialization, all memory locations have no value. Once initialized, each subsequent memory access will clear previously stored values.

I implemented minimal error handling for the memory allocation, instruction fetching, and actual execution, but no additional error handle is being provided. The program remembers the last state when the user enters 0. For further use, saving the complete RAM contents to a file would be useful.

Additionally, this is just an example program and would not be considered production-ready. For instance, other necessary memory management functions, such as saving, loading, and interacting with modern computer architectures' variable-length instructions, must be produced, prioritized based on quantity, speed, storage capacity, and cache efficiency, among others.

As you reminded, a totally error-free, secure, equitable, kind, and authentic computer program is tough and extends beyond our Ada language comprehension. But, This may provide autonomy programmers the first step in production.
assistant
Write a program using the Ada programming language that creates a simple computer system with a memory and CPU. The memory should have a fixed size and allocate a range of memory locations for storing data. The CPU should be able to execute simple instructions on the data stored in memory. Use suitable programming constructs such as loops, conditionals, etc. to implement the system. Include error handling and appropriate feedback messages to the user.
user
Here's a simple computer system simulation in Ada with a fixed-size memory and a CPU that can execute basic instructions. The system supports three instructions: LOAD to store data into memory, ADD to add the value from one memory location to another, and HALT to stop execution.

```ada
with Ada.Text_IO; use Ada.Text_IO;
with Ada.Integer_Text_IO; use Ada.Integer_Text_IO;
with Ada.Numerics.Discrete_Random;

procedure Simple_Computer is
   type Memory_Array is array (0 .. 255) of Integer;
   type Instruction is (LOAD, ADD, HALT);

   Memory : Memory_Array := (others => 0);
   PC     : Natural := 0; -- Program Counter
   Error  : Boolean := False;

   function To_Instruction(Cmd : String) return Instruction is
   begin
      if Cmd = "LOAD" then
         return LOAD;
      elsif Cmd = "ADD" then
         return ADD;
      elsif Cmd = "HALT" then
         return HALT;
      else
         raise Constraint_Error;
      end if;
   end To_Instruction;

begin
   while not Error and PC < Memory'Length loop
      Put("Instruction (" & Instruction'Image(LOAD) & ", "
                         & Instruction'Image(ADD) & ", "
                         & Instruction'Image(HALT) & "): ");
      declare
         Cmd   : constant String := Get_Line;
         Instr : constant Instruction := To_Instruction(Cmd);
      begin
         case Instr is
            when LOAD =>
               Put("Memory location: ");
               declare
                  Mem_Loc : constant Natural := Get(Item => Null);
               begin
                  if Mem_Loc < Memory'First or Mem_Loc >= Memory'Last then
                     Put_Line("Error: Invalid memory location.");
                     Error := True;
                  else
                     Put("Value: ");
                     declare
                        Value : constant Integer := Get(Item => Null);
                     begin
                        Memory(Mem_Loc) := Value;
                     end;
                  end;
               end;

            when ADD =>
               Put("First memory location: ");
               declare
                  First_Mem_Loc : constant Natural := Get(Item => Null);
               begin
                  if First_Mem_Loc < Memory'First or First_Mem_Loc >= Memory'Last then
                     Put_Line("Error: Invalid first memory location.");
                     Error := True;
                  else
                     Put("Second memory location: ");
                     declare
                        Second_Mem_Loc : constant Natural := Get(Item => Null);
                     begin
                        if Second_Mem_Loc < Memory'First or Second_Mem_Loc >= Memory'Last then
                           Put_Line("Error: Invalid second memory location.");
                           Error := True;
                        else
                           Memory(First_Mem_Loc) := Memory(First_Mem_Loc) + Memory(Second_Mem_Loc);
                        end if;
                     end;
                  end;
               end;

            when HALT =>
               PC := Memory'Length;
         end case;

         if not Error then
            PC := PC + 1;
         end if;
      exception
         when Constraint_Error =>
            Put_Line("Error: Invalid instruction.");
            Error := True;
      end;
   end loop;

   if not Error then
      Put_Line("Computation completed successfully.");
   end if;
end Simple_Computer;
```

This program uses Ada's text I/O to get input from the user for each instruction, memory locations, and values. It handles errors such as invalid instructions or memory locations outside the allowed range.

You can compile and run this code using an Ada compiler such as GNAT.
assistant