Tanchangya Alphabet is also called Ka-pat is an Abugida is used for Tanchangya Language. It is the southern Brahmic Language Family. Due to its same scripts family, it is similar with Burmese, Mon, Khmer and Lanna scripts.
The Tanchangya alphabets have been introduced recently in 2012 by adopting the manuscript in Rakhine State as Rupak Debnath published in his Book on Ethnographic Study of Tanchangya of CHT, CADC, South Tripura and Sittwe published by Kreativmind, Kolkata, 2008. Though both the Chakma and Tanchangya were using the present Chakma Alphabets long time back but still unconfirmed yet whose alphabets were belonging to and who introduced those alphabets. However, in order not to get misunderstanding between two communities, Tanchangya has introduced these alphabets which are yet to develop into Unicode. For the time being it is just created as True Font which cannot read in online.
This is written from left to right similar with Brahmi scripts unlike the Kharosti which were used to write from right to left.
There are five independent vowels such as A (a:), S(i), v(ʊ), E(e), and W a(oʊ). The other five vowels are dependent namely, Aa(ɔ) , Aw(ʌ), SI(i:), and vU(u:).
There are thirty-one consonants letter found in Tanchangya alphabets. They are classified into group consonants and miscellaneous consonants.
The alphabets are seemed to be derived from ancient Brahmic scripts which inherited the vowel sound within the consonants. If not independent derivation, it should have derived from Burmese or Mon due to their dwelling with Mon and Burmese from 9th Century B.C (in Tagong the ancient civilisation of Burma according to Trans. Pe Maung Tin & G.H. Luce, The Glass Palace Chronicle of the Kings of Myanmar (Yangon: Unity Publishing House, Third printing April, 2008), 1. ) to until the 15th century (during the 15ht Century they were attacked by the Rakhine king and brought to Arakan in 15th Century from Micchagiri present Thaye in Magwe Division) (Dhanyawady Aye Daw Bung, 4). It is believed that they had used the Brahmi scripts in the earlier stages who were known by the term Thek or Sakya in the northern Myanmar.
Collected from: http://www.utacf.org/tanchangyaalphabet.htm
G.H. Luce (2008), The Glass Palace Chronicle of the Kings of Myanmar, Yangon: Unity Publishing House.
Debnath, Rupak (2008), Ethnographic Study of Tanchangya of CHT, CADC, South Tripura and Sittwe, Kolkata: Kreativmind
Dialects, Orthography and Society (PDF). Work Papers of the Summer Institute of Linguistics. Retrieved 2015-11-20.