Heptavintimal

Heptavintimal (Hep-ta-vin-ti-mal) is a base-27 numeral system. (Also called Septemvigesimal in other number topics. Heptavigesimal is also acceptable.)

It is the ternary equivalent of Hexadecimal. Every three trits or tribble is encoded by a Heptavintimal character.

A 9-trit Tryte can be written with three Heptavintimal characters. "DDD" would be 0.

Styles

• 09AQ (Preferred style for the TNINE)
• AZ0
• 0AZ
• 0KZ

Preferred Style

The 09AQ style of Heptavintimal is the preferred style for the TNINE computer due to it's sequential order when decoding/encoding. The characters 0 - 9 and a - q are put in that very order on the character map. It takes the minimal amount of coding to encode or decode. It's also the most Hexadecimal like and easy to remember.

While I understand the reason behind Douglas W. Jones' form of Heptavintimal, to avoid similarly shaped characters. This can mostly be avoided using a font with distinct enough characters, e.g. Serif fonts when displaying Heptavintimal. It would also take extra work to memorize the characters.

The 0KZ style would require a look up table or other coding to decode and encode as the characters do not follow the character map order between after H. Very much like binary ASCII where the numbers are between values 48-57 and the letters are between values 65-90. The gap must be accounted for in coding.

Chart

Unbalanced Decimal	Balanced Decimal	09AQ	AZ0	0AZ	0KZ
0	-13	0	A	0	0
1	-12	1	B	A	1
2	-11	2	C	B	2
3	-10	3	D	C	3
4	-9	4	E	D	4
5	-8	5	F	E	5
6	-7	6	G	F	6
7	-6	7	H	G	7
8	-5	8	I	H	8
9	-4	9	J	I	9
10	-3	A	K	J	A
11	-2	B	L	K	B
12	-1	C	M	L	C
13	0	D	N	M	D
14	1	E	O	N	E
15	2	F	P	O	F
16	3	G	Q	P	G
17	4	H	R	Q	H
18	5	I	S	R	K
19	6	J	T	S	M
20	7	K	U	T	N
21	8	L	V	U	P
22	9	M	W	V	R
23	10	N	X	W	T
24	11	O	Y	X	V
25	12	P	Z	Y	X
26	13	Q	0	Z	Z

References

• The Ternary Manifesto by Douglas W. Jones - Heptavintimal Encoding of Ternary Values