import random
import mixal

# Initialize an environment
computer = mixal.Computer()

# The location for register J
end_point = 3500

# Load the assembly codes.
# Note that the location for register J is set to HLT
# to make sure the codes halt eventually
computer.loadCodes([
    'X       EQU  1000',
    '        ORIG 3000',
    'MAXIMUM STJ  EXIT',
    'INIT    ENT3 0,1',
    '        JMP  CHANGEM',
    'LOOP    CMPA X,3',
    '        JGE  *+3',
    'CHANGEM ENT2 0,3',
    '        LDA  X,3',
    '        DEC3 1',
    '        J3P  LOOP',
    'EXIT    JMP  *',
    '        ORIG {}'.format(end_point),
    '        HLT',
])

num_numbers, max_val = 100, 0
# Register I1 denotes the number of integers in the memory buffer
computer.rI1.set(num_numbers)
# Register J stores the returning location
computer.rJ.set(end_point)
for i in range(1001, 1001 + num_numbers):
    val = random.randint(0, 100000)
    # Set random values to memory
    computer.memoryAt(i).set(val)
    max_val = max(max_val, val)
# Execute until the HLT operation
computer.executeUntilHalt()
print('Expected:', max_val)
# Register A stores the final maximum value
print('Actual:', computer.rA.value())
# The units of time for executing the codes, exclude the halt operation.
print('Compute Cost:', computer.elapsed())

import mixal

# Initialize an environment
computer = mixal.Computer()

# Pre-defined indices for IO devices
card_reader_index = 16
card_punch_index = 17

computer.loadCodes("""
        ORIG 3000
        IN   100(16)
LIN     JBUS LIN(16)
        OUT  100(17)
LOUT    JBUS LOUT(17)
        """)
# Set the initial value of input device
computer.getDeviceWordAt(card_reader_index, 0).set('PRIME')
computer.executeUntilHalt()
# Check the output text of the output device
print(computer.getDeviceWordAt(card_punch_index, 0).getCharacters())