The combination style also causes some basic problems from the standpoint of Korean linguistics, despite its superiority over the complete style. The definition of Hangeul in Korean linguistics includes all kinds of Hangeul after the invention of Hunmin-Chong’?m. It has, therefore, a broader range and has a larger number of syllables than the concept of everyday Hangeul does. In inputting or outputting all kinds of Hangeul including old Hangeul, some problems emerge, as follows:

First, we need a greater number of syllables represented in the computer codes. The problem of the two styles of Hangeul codes comes down to the number of Hangeul syllables in the long run. While the complete style uses the 2,350 syllables selected on the basis of frequency of current Hangeul, the combination style uses all 11,172 syllables by combinations of initial consonants, medial vowels, and final consonants prescribed in the current Hangeul orthography. Of course, the combination style is superior to the complete style in both the fields of Korean linguistics and everyday use, since the combination style has more syllables than the complete style. The point is how to add to or modify the combination style with 11,172 syllables, not to revise in vain the complete style with its 2,350 syllables.

The number of Hangeul syllables, from the standpoint of Korean linguistics, has to be increased to include the old syllables found in old literature and the old syllables of the stems found through the linguistic analysis of Korean, beyond 11,172 Hangeul orthographic syllables. They must increase the number of initial consonants, medial vowels, and final consonants if they are to be represented in the combination codes. Earlier research by the author shows that there are 51 initial consonants, 27 medial vowels, and 54 final consonants in the old written forms. Furthermore, there may be more syllables in current Hangeul. Some syllables that do not conform to the current rules of Hangeul orthography show up in the forms of dialects analyzed, and also in the literature of the Enlightenment period. The number of consonants and vowels is so far beyond the count of 32 each of initial consonants, medial vowels, and final consonants allowed in the code that we cannot expect to codifiy those consonants and vowels in the current 2-byte combination style. Therefore, we cannot help adding the old syllables to the current combination style, using the complete style, as with Chinese characters.

Second, there is a problem with the Hangeul code system. It is the problem not of the complete style or the combination style, but of the units or the sequential orders of consonants and vowels to be codified in the combination style.

Are diphthongs such as ‘wa, w?, ?y, etc. ......’ or two final consonants such as ‘nh, lk, etc. ……’ to be put together into one unit or split into two units? The values of the codes can be given to no more than 28 graphemes: 17 consonants (except ㅸ) and 11 vowels including the old graphemes taking the view that cardinal Hangeul graphemes consist of 14 consonants and 10 vowels, 24 in all. All two consonants or vowels except the cardinal graphemes are separated into two simple consonants or vowels to be codified. It is, however, neither efficient in computerization nor practical in everyday language use. That is why the so-called ‘N-byte Hangeul’ disappeared after only a short time in use. Therefore, we have no choice but to accept that a syllabic unit is split into an initial consonant, a medial vowel, and a final consonant to be codified as the current 2-byte combination style. But the code units of codified initial consonants, medial vowels, and final consonants need more than the current 2-byte combination style allows.

The current 2-byte combination style has 19 consonants, 21 medial vowels, 27 final consonants, and represents 11,172 syllables produced by their combinations. These Korean consonants and vowels are determined by the current Hangeul orthography, but the computer Hangeul has to be determined by practicability and efficiency in everyday use of Korean within the capabilities of the computer, regardless of the Hangeul orthography. The computer can never simply be attached to Hangeul orthography or vice versa.

It is possible to codify 32 initial consonants, medial vowels, and final consonants respectively in a 2-byte code system, but in MS-DOS, only 32 initial consonants, 24 vowels, and 31 consonants can be codified owing to the constraints of MS-DOS itself. And if FILL CODES -signifying vacant space- are assigned, there remain a filled count of 31 initial consonants, 23 medial vowels, and 30 final consonants. Acceptable consonants and vowels are decided and arranged within the above domain, but it is not desirable to use only Hangeul in the above domain because Chinese and other special symbols are also necessary. Accordingly, its domain becomes smaller as Chinese or special symbols occupy the remaining room.