magic/Magdir/acorn - master - githubmirror/file

magic/Magdir/acorn
92 строки3 KB
Christos Zoulas
PR/773: polluks: Add acorn magic
02 июн 2026, 19:53
02 июн 2026, 19:533baaed6

#------------------------------------------------------------------------------
# $File: acorn,v 1.10 2026/06/02 16:53:30 christos Exp $
# acorn:  file(1) magic for files found on Acorn systems
#

# RISC OS Chunk File Format
# From RISC OS Programmer's Reference Manual, Appendix D
# We guess the file type from the type of the first chunk.
0	lelong		0xc3cbc6c5	RISC OS Chunk data
>12	string		OBJ_		\b, AOF object
>12	string		LIB_		\b, ALF library

# RISC OS AIF, contains "SWI OS_Exit" at offset 16.
16	lelong		0xef000011	RISC OS AIF executable

# RISC OS Draw files
# From RISC OS Programmer's Reference Manual, Appendix E
0	string 		Draw		RISC OS Draw file data

# RISC OS new format font files
# From RISC OS Programmer's Reference Manual, Appendix E
0	string		FONT\0		RISC OS outline font data,
>5	byte		x		version %d
0	string		FONT\1		RISC OS 1bpp font data,
>5	byte		x		version %d
0	string		FONT\4		RISC OS 4bpp font data
>5	byte		x		version %d

# RISC OS Music files
# From RISC OS Programmer's Reference Manual, Appendix E
0	string		Maestro\r	RISC OS music file
>8	byte		x		version %d

>8	byte		x		type %d

# Digital Symphony data files
# From: Bernard Jungen (bern8817@euphonynet.be)
0		string	\x02\x01\x13\x13\x13\x01\x0d\x10	Digital Symphony sound sample (RISC OS),
>8		byte	x	version %d,
>9		pstring	x	named "%s",
>(9.b+19)	byte	=0	8-bit logarithmic
>(9.b+19)	byte	=1	LZW-compressed linear
>(9.b+19)	byte	=2	8-bit linear signed
>(9.b+19)	byte	=3	16-bit linear signed
>(9.b+19)	byte	=4	SigmaDelta-compressed linear
>(9.b+19)	byte	=5	SigmaDelta-compressed logarithmic
>(9.b+19)	byte	>5	unknown format

0	string	\x02\x01\x13\x13\x14\x12\x01\x0b	Digital Symphony song (RISC OS),
>8	byte	x	version %d,
>9	byte	=1	1 voice,
>9	byte	!1	%d voices,
>10	leshort	=1	1 track,
>10	leshort	!1	%d tracks,
>12	leshort	=1	1 pattern
>12	leshort	!1	%d patterns

0	string	\x02\x01\x13\x13\x10\x14\x12\x0e
>9	byte	=0	Digital Symphony sequence (RISC OS),
>>8	byte	x	version %d,
>>10	byte	=1	1 line,
>>10	byte	!1	%d lines,
>>11	leshort	=1	1 position
>>11	leshort	!1	%d positions
>9	byte	=1	Digital Symphony pattern data (RISC OS),
>>8	byte	x	version %d,
>>10	leshort	=1	1 pattern
>>10	leshort	!1	%d patterns

# BBC Micro ROM image type magic
# 16KB 6502 sideways ROMs — name string at offset 9 (Acorn convention)
#

# Language+Service ROMs: JMP at +0 AND +3, target high byte $80-$BF
0	ubyte	0x4c
>2	ubyte	>0x7f
>>2	ubyte	<0xc0
>>>3	ubyte	0x4c
>>>>5	ubyte	>0x7f
>>>>>5	ubyte	<0xc0
>>>>>>9	string	>\0	BBC Micro ROM (%s)

# Service-only ROMs: $00 at +0..+2, JMP at +3, target high byte $80-$BF
0	lelong	0x4c000000
>5	ubyte	>0x7f
>>5	ubyte	<0xc0
>>>9	string	>\0	BBC Micro ROM (%s)

# Language-only ROMs: BASIC II pattern (CMP #$01; BEQ)
0	leshort	0x01c9
>2	leshort	0x1ff0
>>9	string	>\0	BBC Micro ROM (%s)