Subject: Encoding Schemes

From: Rupert Zhu <[email-masked]>
Date: Sat, 9 Mar 91 19:32:22 EST

Yan Yongxin proposed a simple and very natural encoding scheme for
converting Binary into ASCII, with a expansion ratio of 1:2.  His
scheme is to use a pair of HEX numbers to record an 8-bit byte.
After every 39 bytes being recorded, he puts in a '\n'.
This scheme is not bad, provided that ratio is not our major
concern.  (Chinese files are usually small.)

                 COMPARISON CHART

                            Characters Used       Ratio        Safety

ATOB/BTOA                    85  (33--117)        4:5          fair
UUENCODE/UUDECODE            64  (33--96)         3:4          fair
XXENCODE/XXDECODE            64  (+-0-9A-Za-z)    3:4          very good
Natural Scheme (Yan)         16  (0-9A-F)         1:2          very good

Besides these four schemes, the utility disk will also contain
zW <---> CC-DOS
HZ <---> CC-DOS
etc.

-- Rupert