TWX originally used the earlier five-bit ITA2, which was also used by the competing Telex teleprinter system.
tˌiːdˌʌbəljˌuːˈɛks ɚɹˈɪdʒɪnəli jˈuːzd ðɪ ˈɜːlɪɚ fˈaɪvbˈɪt ˌaɪtˌiːˈeɪ tˈuː, wˌɪtʃ wʌz ˈɔːlsoʊ jˈuːzd baɪ ðə kəmpˈiːɾɪŋ tˈɛlᵻks tˈɛlᵻpɹˌɪntɚ sˈɪstəm.