2 #------------------------------------------------------------------------------
3 # $File: acorn,v 1.8 2021/04/26 15:56:00 christos Exp $
4 # acorn: file(1) magic for files found on Acorn systems
7 # RISC OS Chunk File Format
8 # From RISC OS Programmer's Reference Manual, Appendix D
9 # We guess the file type from the type of the first chunk.
10 0 lelong 0xc3cbc6c5 RISC OS Chunk data
11 >12 string OBJ_ \b, AOF object
12 >12 string LIB_ \b, ALF library
14 # RISC OS AIF, contains "SWI OS_Exit" at offset 16.
15 16 lelong 0xef000011 RISC OS AIF executable
18 # From RISC OS Programmer's Reference Manual, Appendix E
19 0 string Draw RISC OS Draw file data
21 # RISC OS new format font files
22 # From RISC OS Programmer's Reference Manual, Appendix E
23 0 string FONT\0 RISC OS outline font data,
25 0 string FONT\1 RISC OS 1bpp font data,
27 0 string FONT\4 RISC OS 4bpp font data
31 # From RISC OS Programmer's Reference Manual, Appendix E
32 0 string Maestro\r RISC OS music file
37 # Digital Symphony data files
38 # From: Bernard Jungen (bern8817@euphonynet.be)
39 0 string \x02\x01\x13\x13\x13\x01\x0d\x10 Digital Symphony sound sample (RISC OS),
41 >9 pstring x named "%s",
42 >(9.b+19) byte =0 8-bit logarithmic
43 >(9.b+19) byte =1 LZW-compressed linear
44 >(9.b+19) byte =2 8-bit linear signed
45 >(9.b+19) byte =3 16-bit linear signed
46 >(9.b+19) byte =4 SigmaDelta-compressed linear
47 >(9.b+19) byte =5 SigmaDelta-compressed logarithmic
48 >(9.b+19) byte >5 unknown format
50 0 string \x02\x01\x13\x13\x14\x12\x01\x0b Digital Symphony song (RISC OS),
54 >10 leshort =1 1 track,
55 >10 leshort !1 %d tracks,
56 >12 leshort =1 1 pattern
57 >12 leshort !1 %d patterns
59 0 string \x02\x01\x13\x13\x10\x14\x12\x0e
60 >9 byte =0 Digital Symphony sequence (RISC OS),
61 >>8 byte x version %d,
63 >>10 byte !1 %d lines,
64 >>11 leshort =1 1 position
65 >>11 leshort !1 %d positions
66 >9 byte =1 Digital Symphony pattern data (RISC OS),
67 >>8 byte x version %d,
68 >>10 leshort =1 1 pattern
69 >>10 leshort !1 %d patterns
71 # From: Joerg Jenderek
72 # URL: https://www.kyzer.me.uk/pack/xad/#PackDir
73 # reference: https://www.kyzer.me.uk/pack/xad/xad_PackDir.lha/PackDir.c
74 # GRR: line below is too general as it matches also "Git pack" in ./revision
76 # check for valid compression method 0-4
78 # https://www.riscosopen.org/wiki/documentation/show/Introduction%20To%20Filing%20Systems
79 # To skip "Git pack" version 0 test for root directory object like
80 # ADFS::RPC.$.websitezip.FONTFIX
81 >>9 string >ADFS\ PackDir archive (RISC OS)
82 # TrID labels above as "Acorn PackDir compressed Archive"
83 # compression mode y (0 - 4) for GIF LZW with a maximum n bits
84 # (y~n,0~12,1~13,2~14,3~15,4~16)
85 >>>5 ulelong+12 x \b, LZW %u-bits compression
86 # https://www.filebase.org.uk/filetypes
87 # !Packdir compressed archive has three hexadecimal digits code 68E
88 !:mime application/x-acorn-68E
90 # null terminated root directory object like IDEFS::IDE-4.$.Apps.GRAPHICS.!XFMPdemo
91 >>>9 string x \b, root "%s"
92 # load address 0xFFFtttdd, ttt is the object filetype and dddddddddd is time
93 >>>>&1 ulelong x \b, load address %#x
94 # execution address 0xdddddddd dddddddddd is 40 bit unsigned centiseconds since 1.1.1900 UTC
95 >>>>&5 ulelong x \b, exec address %#x
96 # attributes (bits: 0~owner read,1~owner write,3~no delete,4~public read,5~public write)
97 >>>>&9 ulelong x \b, attributes %#x
98 # number of entries in this directory. for root dir 0
99 #>>>&13 ulelong x \b, entries %#x
100 # the entries start here with object name
101 >>>>&17 string x \b, 1st object "%s"