MacWrite was the word processor on early Macintosh computers. It originally was released by Apple as one of the programs that came with a Macintosh, but was later spun off to Claris as a separate software product; this did not succeed in competition with other word processors, so it was eventually discontinued by the mid-1990s.
The first two bytes of a MacWrite file are a big-endian integer distinguishing MacWrite versions.
MacWrite versions 1.0 - 2.2 used version 00 03 in this field.
MacWrite versions 4.5 - 5.0 used version 00 06 in this field.
MacWrite II used version 00 2E in this field.
MacWrite Pro used version 00 04 in this field.
MacWrite 2.2 stored text in a compression scheme where the (language-specific) most common characters (for English, " etnroaisdlhcfp" in that order, with the space character first) were stored as one nybble each (half a byte), where the values 0 through E corresponded to the characters in the most-common list. The nybble value F signaled that a different character followed, meaning that characters not on the list took three nybbles (a byte and a half) to store. This usually averaged out to a savings, since the most common characters typically make up a high portion of the text.
MacWrite 3.x and up used a different compression system, and were designed so files could be edited directly on disk without loading the entire file into memory.
|Version 1.0||1984.01.24||Encore Systems||WORD/MACA|
|Version 2.2||1984.05||Encore Systems||WORD/MACA|
|Version 4.5||1985.04||Encore Systems||WORD/MACA|
|Version 4.6||1987.07||Encore Systems||WORD/MACA|