OS_ROM_URL = 'http://www.bbcmicrogames.com/roms/os12.zip'

import requests         # downloading the zipfile
from io import BytesIO  # treating a bytes object as file
import zipfile          # parsing the zipfile

# Fetch the ROM and check that the GET succeeded
os_rom_zip_req = requests.get(OS_ROM_URL)
assert os_rom_zip_req.status_code == 200

# Parse the body as a zip file
os_rom_zip = zipfile.ZipFile(BytesIO(os_rom_zip_req.content))

print('Archive contents: ' + ','.join(os_rom_zip.namelist()))
assert len(os_rom_zip.filelist) == 1

font_table = os_rom_zip.read(os_rom_zip.filelist[0])[:0x300]

import numpy as np
from bitarray import bitarray

font_table_array = bitarray(endian='big')
font_table_array.frombytes(font_table)
font = np.array(font_table_array.tolist()).reshape((-1, 8))

n_chars = font.shape[0] // 8
print('Number of characters: {0}'.format(n_chars))

%matplotlib inline
from matplotlib.pyplot import *

imshow(font[:8*3, :], interpolation='none', cmap='gray')

char_arrays = np.split(font, n_chars)

# check that we've split correctly
imshow(char_arrays[20], interpolation='none', cmap='gray')

font_image = np.vstack(tuple(
    np.hstack(row).reshape((8, -1)) for row in np.array(char_arrays).reshape((-1, 16, 8, 8))
))

print('Generated font image of shape: ' + 'x'.join(str(x) for x in font_image.shape))

imshow(font_image, cmap='gray', interpolation='none')

import json
from imgurpython import ImgurClient

imgur_creds = json.load(open('imgur-credentials.json'))
imgur_client = ImgurClient(imgur_creds['clientId'], imgur_creds['clientSecret'])

import tempfile
from PIL import Image

with tempfile.NamedTemporaryFile(suffix='.png') as tf:
    Image.fromarray(np.where(font_image, 255, 0).astype(np.uint8)).save(tf.name)
    upload_result = imgur_client.upload_from_path(tf.name)
print('Image uploaded to: {0}'.format(upload_result['link']))

from IPython.display import Image
Image(upload_result['link'])