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BeebUtils.pm
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package BeebUtils;
# Beeb Utilities to manipulate MMB and SSD files
# Copyright (C) 2012 Stephen Harris
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
use warnings;
use strict;
use FileHandle;
use POSIX;
# Constants
my $SecSize=256;
my $DiskTableSize=32*$SecSize;
my $DisksPerCatalog = ($DiskTableSize/16)-1; # slot 0 isn't a real disk
my $MaxDisks = $DisksPerCatalog;
my $NumTables = 1; # Multiple tables
my $DiskCatalogueSize = 2 * $SecSize ; # DFS
my $DiskSectors = 800 ; # Only size supported! 80track single density
my $DiskSize = $DiskSectors * $SecSize;
our $MMBSize = $DisksPerCatalog*$DiskSize+$DiskTableSize;
my $CatalogueMaxFiles = 31; # Acorn maximum. Solidisk can exceed this
# but we only read that format
# Disk table values
my $DiskReadOnly = 0;
my $DiskReadWrite = 0xF;
my $DiskUnformatted = 0xF0;
my $DiskInvalid = 0xFF;
# Almost a constant. What we're gonna do here is nasty, but it means
# that any program that uses this module will automatically gain an
# optional "-f filename"
my $DEFAULT_BBC_FILE=defined $ENV{'BBC_FILE'} ? $ENV{'BBC_FILE'} : "BEEB.MMB";
our $BBC_FILE="";
# These values extracted from BASIC 2 ROM
# starting at &8071 and ending at &836C
# (see extract_tokens for how this was built)
# This is "our" so external programs can see it
our %basic_tokens;
our %extended_tokens;
# z80 uses different line definitions
# Basic 1/2/4 is <OD><lineno-high><lineno-low><len> and ends with linehi=ff
# z80 and Basic 4 windows is <FF><lineno-low><lineno-high> and ends with
# len=0 lineno=ffff
our %alt_line;
$basic_tokens{"_BASE_"}=
{
128 => ['AND',0x00], 192 => ['LEFT$(',0x00],
129 => ['DIV',0x00], 193 => ['MID$(',0x00],
130 => ['EOR',0x00], 194 => ['RIGHT$(',0x00],
131 => ['MOD',0x00], 195 => ['STR$',0x00],
132 => ['OR',0x00], 196 => ['STRING$(',0x00],
133 => ['ERROR',0x04], 197 => ['EOF',0x01],
134 => ['LINE',0x00], 198 => ['AUTO',0x10],
135 => ['OFF',0x00], 199 => ['DELETE',0x10],
136 => ['STEP',0x00], 200 => ['LOAD',0x02],
137 => ['SPC',0x00], 201 => ['LIST',0x10],
138 => ['TAB(',0x00], 202 => ['NEW',0x01],
139 => ['ELSE',0x14], 203 => ['OLD',0x01],
140 => ['THEN',0x14], 204 => ['RENUMBER',0x10],
142 => ['OPENIN',0x00], 205 => ['SAVE',0x02],
143 => ['PTR',0x43], 207 => ['PTR',0x00],
144 => ['PAGE',0x43], 208 => ['PAGE',0x00],
145 => ['TIME',0x43], 209 => ['TIME',0x00],
146 => ['LOMEM',0x43], 210 => ['LOMEM',0x00],
147 => ['HIMEM',0x43], 211 => ['HIMEM',0x00],
148 => ['ABS',0x00], 212 => ['SOUND',0x02],
149 => ['ACS',0x00], 213 => ['BPUT',0x03],
150 => ['ADVAL',0x00], 214 => ['CALL',0x02],
151 => ['ASC',0x00], 215 => ['CHAIN',0x02],
152 => ['ASN',0x00], 216 => ['CLEAR',0x01],
153 => ['ATN',0x00], 217 => ['CLOSE',0x03],
154 => ['BGET',0x01], 218 => ['CLG',0x01],
155 => ['COS',0x00], 219 => ['CLS',0x01],
156 => ['COUNT',0x01], 220 => ['DATA',0x20],
157 => ['DEG',0x00], 221 => ['DEF',0x00],
158 => ['ERL',0x01], 222 => ['DIM',0x02],
159 => ['ERR',0x01], 223 => ['DRAW',0x02],
160 => ['EVAL',0x00], 224 => ['END',0x01],
161 => ['EXP',0x00], 225 => ['ENDPROC',0x01],
162 => ['EXT',0x01], 226 => ['ENVELOPE',0x02],
163 => ['FALSE',0x01], 227 => ['FOR',0x02],
164 => ['FN',0x08], 228 => ['GOSUB',0x12],
165 => ['GET',0x00], 229 => ['GOTO',0x12],
166 => ['INKEY',0x00], 230 => ['GCOL',0x02],
167 => ['INSTR(',0x00], 231 => ['IF',0x02],
168 => ['INT',0x00], 232 => ['INPUT',0x02],
169 => ['LEN',0x00], 233 => ['LET',0x04],
170 => ['LN',0x00], 234 => ['LOCAL',0x02],
171 => ['LOG',0x00], 235 => ['MODE',0x02],
172 => ['NOT',0x00], 236 => ['MOVE',0x02],
173 => ['OPENUP',0x00], 237 => ['NEXT',0x02],
174 => ['OPENOUT',0x00], 238 => ['ON',0x02],
175 => ['PI',0x01], 239 => ['VDU',0x02],
176 => ['POINT(',0x00], 240 => ['PLOT',0x02],
177 => ['POS',0x01], 241 => ['PRINT',0x02],
178 => ['RAD',0x00], 242 => ['PROC',0x0A],
179 => ['RND',0x01], 243 => ['READ',0x02],
180 => ['SGN',0x00], 244 => ['REM',0x20],
181 => ['SIN',0x00], 245 => ['REPEAT',0x00],
182 => ['SQR',0x00], 246 => ['REPORT',0x01],
183 => ['TAN',0x00], 247 => ['RESTORE',0x12],
184 => ['TO',0x00], 248 => ['RETURN',0x01],
185 => ['TRUE',0x01], 249 => ['RUN',0x01],
186 => ['USR',0x00], 250 => ['STOP',0x01],
187 => ['VAL',0x00], 251 => ['COLOUR',0x02],
188 => ['VPOS',0x01], 252 => ['TRACE',0x12],
189 => ['CHR$',0x00], 253 => ['UNTIL',0x02],
190 => ['GET$',0x00], 254 => ['WIDTH',0x02],
191 => ['INKEY$',0x00], 255 => ['OSCLI',0x02]
};
$basic_tokens{"basic2"}={};
$extended_tokens{"basic2"}={};
# These extensions from http://mdfs.net/Docs/Comp/BBCBasic/Tokens
$basic_tokens{"basic4"}= { 206 => ['EDIT',0] };
$extended_tokens{"basic4"}={};
$basic_tokens{"z80"}= { 206 => ['PUT',0] };
$extended_tokens{"z80"}={};
$alt_line{"z80"}=1;
$basic_tokens{"arm"}=
{
127 => ['OTHERWISE',0], 204 => ['ELSE',0],
201 => ['WHEN',0], 205 => ['ENDIF',0],
202 => ['OF',0], 206 => ['ENDWHILE',0],
203 => ['ENDCASE',0]
};
$extended_tokens{"arm"}{198}={ 142 => ['SUM',0], 143 => ['BEAT',0] };
$extended_tokens{"arm"}{199}=
{
142 => ['APPEND',0], 151 => ['NEW',0],
143 => ['AUTO',0], 152 => ['OLD',0],
144 => ['CRUNCH',0], 153 => ['RENUMBER',0],
145 => ['DELETE',0], 154 => ['SAVE',0],
146 => ['EDIT',0], 155 => ['TEXTLOAD',0],
147 => ['HELP',0], 156 => ['TEXTSAVE',0],
148 => ['LIST',0], 157 => ['TWIN',0],
149 => ['LOAD',0], 158 => ['TWINO',0],
150 => ['LVAR',0], 159 => ['INSTALL',0]
};
$extended_tokens{"arm"}{200}=
{
142 => ['CASE',0], 155 => ['LIBRARY',0],
143 => ['CIRCLE',0], 156 => ['TINT',0],
144 => ['FILL',0], 157 => ['ELLIPSE',0],
145 => ['ORIGIN',0], 158 => ['BEATS',0],
146 => ['POINT',0], 159 => ['TEMPO',0],
147 => ['RECTANGLE',0], 160 => ['VOICES',0],
148 => ['SWAP',0], 161 => ['VOICE',0],
149 => ['WHILE',0], 162 => ['STEREO',0],
150 => ['WAIT',0], 163 => ['OVERLAY',0],
151 => ['MOUSE',0], 164 => ['MANDEL',0],
152 => ['QUIT',0], 165 => ['PRIVATE',0],
153 => ['SYS',0], 166 => ['EXIT',0],
154 => ['INSTALL',0]
};
$basic_tokens{"b4w"}=
{
1 => ['CIRCLE',0], 198 => ['SUM',0],
2 => ['ELLIPSE',0], 199 => ['WHILE',0],
3 => ['FILL',0], 200 => ['CASE',0],
4 => ['MOUSE',0], 201 => ['WHEN',0],
5 => ['ORIGIN',0], 202 => ['OF',0],
6 => ['QUIT',0], 203 => ['ENDCASE',0],
7 => ['RECTANGLE',0], 204 => ['ELSE',0],
8 => ['SWAP',0], 205 => ['ENDIF',0],
9 => ['SYS',0], 206 => ['ENDWHILE',0],
10 => ['TINT',0],
11 => ['WAIT',0],
12 => ['INSTALL',0],
14 => ['PRIVATE',0],
15 => ['BY',0],
16 => ['EXIT',0],
};
$extended_tokens{"b4w"}={};
$alt_line{"b4w"}=1;
my $SOLIDISK=0;
my $WATFORD=0;
my $OPUS=0;
my $DISK_DOCTOR=0;
sub init(@)
{
my (@arg)=@_;
if (@arg >=2 && $arg[0] eq '-f')
{
$BBC_FILE=$arg[1];
shift @arg;
shift @arg;
}
elsif (@arg && $arg[0] =~ /^-f(.+)$/)
{
$BBC_FILE=$1;
shift @arg;
}
elsif (@arg==1 && $arg[0] eq '-f')
{
die "Missing filename argument to -f\n";
}
# We need to check the MMB file to see if it's an extended one
# and if so, set NumTables and MaxDisks
# An entry of 0xA# at offset 8 in the table (previously unused)
# means there's # additional tables
my $fname=$BBC_FILE;
$fname=$DEFAULT_BBC_FILE unless $fname;
my $fh = new FileHandle("+< $fname");
if ($fh)
{
binmode($fh);
sysseek($fh,8,0);
my $ext_byte;
sysread($fh,$ext_byte,1);
close($fh);
$ext_byte=ord($ext_byte);
if ($ext_byte > 160 && $ext_byte < 176)
{
# We have 1-15 catalogues
$NumTables = $ext_byte-159;
$MaxDisks = $NumTables * $MaxDisks;
}
}
return(@arg);
}
sub init_ssd(@)
{
my (@arg)=@_;
if (@arg)
{
my $f=$arg[0];
if ($f=~/^([^:]+):(.+)$/)
{
$f=$2;
check_and_set_type($1);
}
$BBC_FILE=$f;
shift @arg;
}
return (@arg);
}
my $file_handle=undef;
# Open BBC_FILE if it's not already open
sub OpenFile()
{
return if $file_handle;
$BBC_FILE=$DEFAULT_BBC_FILE unless $BBC_FILE;
die "$BBC_FILE is not a file!\n" unless -f $BBC_FILE;
$file_handle = new FileHandle("+< $BBC_FILE");
die "Could not open $BBC_FILE: $!\n" unless $file_handle;
binmode($file_handle);
return;
}
sub LoadDiskTable(;$)
{
my ($extent)=@_;
$extent=0 unless $extent;
my ($disktable,$thistable);
OpenFile;
sysseek($file_handle,$extent*$MMBSize,0);
sysread($file_handle,$disktable,$DiskTableSize);
# Add any secondary catalogues
foreach my $i (1..$NumTables-1)
{
# We skip the first 16 bytes since they're unused in secondary catalogues
sysseek($file_handle,$i*$MMBSize+16,0);
sysread($file_handle,$thistable,$DiskTableSize-16);
# If the MMB is short then abort
if (length($thistable) != $DiskTableSize-16)
{
printf("Unable to read MMB Catalogue %d at location %d\n Got %d bytes but expected %d\n Is this a corrupted MMB?\n",$i,$i*$MMBSize+16,length($thistable),$DiskTableSize-16);
exit(-1);
}
$disktable .= $thistable
}
return $disktable;
}
sub SaveDiskTable($)
{
my ($disktable)=@_;
OpenFile;
my $thistable=$$disktable;
sysseek($file_handle,0,0);
syswrite($file_handle,$thistable,$DiskTableSize);
$thistable=substr($thistable,$DiskTableSize);
foreach my $i (1..$NumTables-1)
{
# We skip the first 16 bytes since they're unused in secondary catalogues
sysseek($file_handle,$i*$MMBSize+16,0);
syswrite($file_handle,$thistable,$DiskTableSize-16);
$thistable=substr($thistable,$DiskTableSize-16);
}
}
# Disk slot and new title and table
sub ChangeDiskName($$$)
{
my ($slot,$title,$disktable)=@_;
return if $slot < 0 || $slot >= $MaxDisks;
$title.=("\0"x15); $title=substr($title,0,15);
substr($$disktable,$slot*16+16,15)=$title;
}
# Delete slot
sub DeleteSlot($$$)
{
my ($slot,$restore,$disktable)=@_;
return if $slot < 0 || $slot >= $MaxDisks;
substr($$disktable,$slot*16+16+15,1)=chr($restore?$DiskReadWrite:$DiskUnformatted);
}
# Lock/Unlock a slot
sub lock_disk($$$)
{
my ($slot,$lock,$disktable)=@_;
return if $slot < 0 || $slot >= $MaxDisks;
substr($$disktable,$slot*16+16+15,1)=chr($lock?$DiskReadOnly:$DiskReadWrite);
}
# disk is disk slot on the MMB (0->$MaxDisks-1)
# disktable is a reference to a already loaded disktable
# eg
# my $disktable=LoadDiskTable;
# my ($title,$type)=GetDskName(10,\$disktable);
sub GetDskName($$)
{
my ($disk,$disktable)=@_;
my $offset=$disk*16+16;
my $title=substr($$disktable,$offset,12); $title =~ s/\0.*$//;
# Convert any non-ascii character to a '?'
$title =~ s/[\x01-\x1f\x7f-\xff]/?/g;
# Ensure title is 12 characters long
$title .= " "x(12-length($title));
my $type=substr($$disktable,$offset+15,1); $type=ord($type);
return ($title,$type);
}
# Returns a simple hashref of boot image and the disk catalog
sub load_onboot(;$)
{
my ($extent)=@_;
my $disktable=LoadDiskTable($extent);
my %boot;
foreach (0..3)
{
$boot{$_}=ord(substr($disktable,$_,1))+ord(substr($disktable,$_+4,1))*256;
}
return ($disktable,%boot);
}
sub save_onboot($%)
{
my ($disktable,%boot)=@_;
foreach (0..3)
{
substr($$disktable,$_,1)=chr($boot{$_} & 0xff);
substr($$disktable,$_+4,1)=chr(($boot{$_} & 0xff00) >> 8);
}
SaveDiskTable($disktable);
}
sub DiskPtr($;$)
{
my ($DiskNo,$Sec)=@_;
$Sec=0 unless $Sec;
# If the image is in a secondary catalogue then we need to add extra
# DiskTableSize offsets
my $offset=1+int($DiskNo/$DisksPerCatalog);
return ($DiskTableSize*$offset)+($DiskNo*$DiskSize)+($Sec*$SecSize);
}
sub BootOpt($)
{
my ($bytOption)=@_;
if ($bytOption == 0) { return 'None'; }
if ($bytOption == 1) { return 'LOAD'; }
if ($bytOption == 2) { return 'RUN'; }
if ($bytOption == 3) { return 'EXEC'; }
return "";
}
sub DiskSize($)
{
my ($size)=@_;
# If we want more detail, comment this line out...
return int($size/4) . "K";
if ($size == 0x190) { return "100K - 40x10 - SD"; }
if ($size == 0x280) { return "160K - 40x16 - DD"; }
if ($size == 0x2d0) { return "180K - 40x18 - DD"; }
if ($size == 0x320) { return "200K - 80x10 - SD"; }
if ($size == 0x500) { return "320K - 80x16 - DD"; }
if ($size == 0x5a0) { return "360K - 80x18 - DD"; }
return int($size/4) . "K";
}
# Loads the main catalog from the MMB file
# (optionally pass an already loaded disktable)
sub load_dcat(;$)
{
my ($tbl)=@_;
my ($disktable,%disk);
if ($tbl)
{
$disktable=$$tbl;
}
else
{
$disktable=LoadDiskTable;
}
foreach (0..$MaxDisks-1)
{
$disk{$_}{ValidDisk}=0;
$disk{$_}{Formatted}=0;
$disk{$_}{ReadOnly}=0;
$disk{$_}{DiskTitle}="";
my ($title,$type)=GetDskName($_,\$disktable);
if ($type == $DiskReadOnly || $type == $DiskReadWrite)
{
$disk{$_}{ValidDisk}=1;
$disk{$_}{Formatted}=1;
$disk{$_}{ReadOnly}=($type == $DiskReadOnly)?1:0;
$disk{$_}{DiskTitle}=$title;
}
elsif ($type == $DiskUnformatted)
{
$disk{$_}{ValidDisk}=1;
$disk{$_}{DiskTitle}=$title;
}
}
return %disk;
}
sub blank_mmb()
{
my $image="\0" x $MMBSize;
substr($image,0,4)="\0\1\2\3"; # Default onboot disks
foreach (1..$DisksPerCatalog)
{
substr($image,$_*16+15,1)=chr($DiskUnformatted);
}
return($image);
}
sub blank_ssd()
{
my $image="\xE5" x $DiskSize;
substr($image,0,512)="\x0" x 512;
substr($image,0x104,4)="\x01\x00\x03\x20"; # 200K disk
return($image);
}
# Reads an SSD image from an MMB
sub read_ssd(;$)
{
my ($disk)=@_;
OpenFile;
sysseek($file_handle,DiskPtr($disk),0) if defined($disk);
my $image;
sysread($file_handle,$image,$DiskSize);
# Ensure the image is at least the right size
die "Image is too small; not even 2 sectors!\n" if length($image)<512;
$image .= blank_ssd();
$image=substr($image,0,$DiskSize);
return($image);
}
# Reads an SSD from an external file
sub load_external_ssd(;$$)
{
my ($fname,$size_check)=@_;
my $target=$fname||$BBC_FILE;
die "$target is not a file!\n" unless -f $target || $target eq '-';
my $f=new FileHandle "<$target";
die "Could not open $target: $!\n" unless $f;
binmode($f);
my $image;
# We won't read more than 400K, regardless
sysread($f,$image,409600);
if ($size_check && length($image)> $DiskSize)
{
die "File $target is over $DiskSize in size\n";
}
close($f);
# Ensure the image is at least the right size
die "Image is too small; not even 2 sectors!\n" if length($image)<512;
if (length($image) < $DiskSize)
{
$image .= blank_ssd();
$image=substr($image,0,$DiskSize);
}
return($image);
}
sub put_ssd($$)
{
my ($image,$disk)=@_;
die "$disk is greater than maximum allowed of " . ($MaxDisks-1) . " for this MMB \n" if $disk >= $MaxDisks;
OpenFile;
sysseek($file_handle,DiskPtr($disk),0);
syswrite($file_handle,$image,$DiskSize);
}
sub write_ssd($$)
{
my ($image,$filename)=@_;
my $fh=new FileHandle ">$filename";
die "Can not open $filename for saving\n" unless $fh;
binmode($fh);
print $fh $$image;
close($fh);
}
sub set_ssd_title($$)
{
my ($image,$title)=@_;
$title .= ("\0"x12);
my $t1=substr($title,0,8);
my $t2=substr($title,8,4);
# If Solidisk secondary catalog then cut down title by 2
my @b=unpack("C",substr($$image,0x102,1));
$t2=substr($t2,0,2) if ($b[0] & 192) == 192;
substr($$image,0,8)=$t1;
substr($$image,0x100,length($t2))=$t2;
}
# Reads a standard BBC DFS catalogue.
# $image is a ref to a loaded disk image
# $start is a sector offset into the image to find the catalog
sub _read_ssd_cat($$)
{
my ($image,$start)=@_;
my $offset=$start*256;
my %files;
# BBC disk format: First 8 bytes are part of the disk title; null terminated
my $disk_title=substr($$image,$offset,8);
# We'll grab the filecount from sector 1 'cos that makes it easier...
my $filecount=ord(substr($$image,$offset+256+5,1))/8;
# Next lot of 8 data are filenames
foreach (0..$filecount-1)
{
my $t=substr($$image,$offset+$_*8+8,7); $t=~s/ .*$//;
my $d=substr($$image,$offset+$_*8+8+7,1); $d=ord($d);
my $locked=($d>127)?1:0;
$d=chr($d%128);
$t="$d.$t"; $t=~s/\0.*$//;
$files{$_}{locked}=$locked;
$files{$_}{name}="$t";
$files{$_}{cat_sector}=$start;
}
# Second sector.
# First 4 bytes are also part of the title
my $t2=substr($$image,$offset+256,4); $disk_title .= $t2;
# Disk title is null terminated. But quick check to see if's a solidisk
# chained catalogue. No one should use high-bit characters in disk
# titles, so this is relative safe to do.
my $chained;
if ($SOLIDISK)
{
my @b=unpack("C2",substr($disk_title,10,2));
if (($b[0] & 192) == 192)
{
$chained=($b[0]&63)*256+$b[1];
$disk_title=substr($disk_title,0,10);
}
}
$disk_title=~s/\0.*$//;
# next byte is BCD cycle
my $cycle=substr($$image,$offset+256+4,1); $cycle=ord($cycle);
$cycle=int($cycle/16)*10+($cycle%16);
# (We'd already got the filecount, earlier)
# Now the last next two bytes encode both *OPT4 value and disk size
my @b=unpack("C2",substr($$image,$offset+256+6,2));
my $opt4=int($b[0]/16) & 3;
# Really this should only be &3 but DD disks need 11 bits, so...
# (relatively safe to do everywhere - bit 3 was unused, otherwise)
my $disk_size=($b[0]&7)*256+$b[1];
# Now we have entries for load/exec/size/start-sec
# LL LL EE EE SS SS XX YY
# Load Exec Size Sector
# The first 6 bytes are load/exec/size bottom 16 bits.
# The 8th byte encodes the low 8 bits for start-sec
# The 7th byte is special. For Acorn DFS:
# bits 0+1 are high bits of sector start
# bits 2+3 are high bits of load address
# bits 4+5 are high bits of size
# bits 6+7 are high bits of exec address
#
# That makes 10 bits for start sector and 18 bits for size.
#
# But on a 320K disk you need 11 bits and 19 bits. So Solidisk steals
# bits 2 and 3 ("load address"). bit 2 is added to the sector, bit 3 to
# the size. This means we have now only have 8 bits for the load address.
# Solidisk re-uses the exec high bits for the load high bits.
foreach (0..$filecount-1)
{
my ($load,$exec,$size,$sec);
@b=unpack("C2",substr($$image,$offset+256+$_*8+8 ,2)); $load=$b[1]*256+$b[0];
@b=unpack("C2",substr($$image,$offset+256+$_*8+8+2,2)); $exec=$b[1]*256+$b[0];
@b=unpack("C2",substr($$image,$offset+256+$_*8+8+4,2)); $size=$b[1]*256+$b[0];
# Higher bits are encoded
@b=unpack("C",substr($$image,$offset+256+$_*8+8+6,1));
my $highsec = ($b[0]&3); # bits 0 and 1
my $highload = ($b[0] & 0xc) >> 2; # bits 2 and 3
my $highsize = ($b[0] & 0x30) >> 4; # bits 4 and 5
my $highexec = ($b[0] & 0xc0) >> 6; # bits 6 and 7
if ($SOLIDISK && $disk_size == 0x500)
{
if ($highload & 1) { $highsec += 4; }
if ($highload & 2) { $highsize += 4; }
$highload=$highexec;
}
# Watford does it slightly differently and uses high bits in the
# filename which means we'll need to recalculate it.
if ($WATFORD)
{
my $name=$files{$_}{name};
@b=unpack("C2",substr($$image,$offset+$_*8+8+5,2));
if ($b[0]>127)
{
substr($name,5,1)=chr($b[0] & 127) if length($name)>5;
$highsize += 4;
}
if ($b[1]>127)
{
substr($name,6,1)=chr($b[1] & 127) if length($name)>6;
$highsec += 4;
}
$files{$_}{name}=$name;
}
$highload=0xff if $highload == 3;
$highexec=0xff if $highexec == 3;
@b=unpack("C",substr($$image,$offset+256+$_*8+8+7,1));
$sec=$b[0];
$files{$_}{load}=$load+$highload*65536;
$files{$_}{exec}=$exec+$highexec*65536;
$files{$_}{size}=$size+$highsize*65536;
$files{$_}{start}=$sec+$highsec*256;
}
# Do we have multi-catalogues? We've already checked for solidisk, earlier
# what about the others?
if ($WATFORD && $start==0)
{
if (substr($$image,512,8) eq "\xAA"x8)
{
$chained=2; # Watford DFS allows another catalogue at sector 2
}
}
if ($start == 0)
{
$files{""}{title}=$disk_title;
$files{""}{cycle}=$cycle;
$files{""}{disk_size}=$disk_size;
$files{""}{opt4}=$opt4;
}
$files{""}{filecount}=$filecount;
$files{""}{chain}=$chained;
return %files;
}
# Read disk catalgue. Follow chain if multi-catalogues
# If $0 is a reference to a BBC disk image
sub read_cat($)
{
my ($image)=@_;
# OPUS is sufficiently different...
if ($OPUS) { return read_cat_opus($image); }
my %files;
my $max_file=0;
my $chain=0;
my $deleted=0;
while ($chain ne "")
{
my %this_cat=_read_ssd_cat($image,$chain);
$files{""}{last_cat}=$chain;
if ($chain == 0)
{
foreach my $k (keys %{$this_cat{""}})
{
$files{""}{$k}=$this_cat{""}{$k};
}
}
else
{
$files{""}{filecount}+=$this_cat{""}{filecount};
}
my $nextchain=$this_cat{""}{chain} || "";
delete($this_cat{""});
foreach (sort { $a <=> $b } keys %this_cat)
{
next if $_ eq "";
# Skip deleted files from multi-catalog (directory is 0x7F
# and file is locked
if ($SOLIDISK && $this_cat{$_}{name} =~ /^\x7f\./ && $this_cat{$_}{locked})
{
$deleted++;
next;
}
# Is this a hidden file that "blocks out" data from first catalogue?
# If so, it's the end of this 2nd catalogue
if ($SOLIDISK && $this_cat{$_}{name} eq '?.???????' && $this_cat{$_}{locked} && $chain)
{
$deleted++;
next;
}
#Disk doctor?
if ($DISK_DOCTOR && $this_cat{$_}{name} eq '!.!!!!!!!' && $this_cat{$_}{locked})
{
$deleted++;
$nextchain=2 unless $chain;
next;
}
foreach my $k (keys %{$this_cat{$_}})
{
$files{$max_file}{$k}=$this_cat{$_}{$k};
}
$max_file++ unless $_ eq "";
}
$chain=$nextchain;
}
$files{""}{deleted}=$deleted;
return %files;
}
# OPUS...
sub read_cat_opus($)
{
my ($image)=@_;
# if this isn't an opus image then abort 'cos it could
# be almost anything
# The four bytes should be 20 05 a0 12
if (substr($$image,0x1000,4) ne "\x20\x05\xa0\x12")
{
die "This does not appear to be an OPUS DDOS image\n";
}
my %catstart;
foreach my $cat (0..7)
{
my @b=unpack("C2",substr($$image,0x1008+$cat*2,2));
# This is measured in tracks, so *18 for sector
$catstart{$cat}=($b[0]+256*$b[1])*18;
# printf "debug: %d at %03X\n",$cat,$catstart{$cat};
}
my %files;
my $max_file=0;
$files{""}{last_cat}=7; # DDOS always has multi-cat even if they're empty
foreach my $chain (0..7)
{
next unless $catstart{$chain};
my %this_cat=_read_ssd_cat($image,$chain*2);
if ($chain == 0)
{
foreach my $k (keys %{$this_cat{""}})
{
$files{""}{$k}=$this_cat{""}{$k};
}
$files{""}{disk_size}=0x5a0;
}
else
{
$files{""}{filecount}+=$this_cat{""}{filecount};
}
delete($this_cat{""});
foreach (sort { $a <=> $b } keys %this_cat)
{
next if $_ eq "";
$this_cat{$_}{start}+=$catstart{$chain};
foreach my $k (keys %{$this_cat{$_}})
{
$files{$max_file}{$k}=$this_cat{$_}{$k};
}
$max_file++ unless $_ eq "";
}
}
$files{""}{deleted}=0;
return %files;
}
# Reference to image; generate a CRC
sub CalcCrc($)
{
my ($image)=@_;
my $crc=0;
foreach (0..length($$image)-1)
{
$crc ^= (256*ord(substr($$image,$_,1)));
foreach my $x (0..7)
{
$crc *= 2;
if ($crc > 65535)
{
$crc-=65535; $crc ^= 0x1020;
}
}
}
return($crc);
}
# Get a file from an SSD image
# $0 is ref to an image
# $1 is the filename
# $2 is a catalogue; we'll build one if not provided
# If you provide a catalogue for a different image then you get
# all you deserve
sub ExtractFile($$;%)
{
my ($image,$filename,%cat)=@_;
my %files;
if (%cat)
{
%files=%cat;
}
else
{
%files=read_cat($image);
}
my $file=undef;
foreach (sort keys %files)
{
my $f=$files{$_}{name};
next unless $f;
$file=$_ if lc($filename) eq lc($f);
}
die "Can not find $filename in image\n" unless defined($file);
my $start=$files{$file}{start}*256;
my $size=$files{$file}{size};
return substr($$image,$start,$size);
}
# SSD image saved to current directory
sub save_all_files_from_ssd($;$$$)
{
my ($image,$verbose,$overwrite,$filter)=@_;
$overwrite //= 0;
$filter //= '^.*$';
my $filter_regex = qr/$filter/;
my %files=read_cat($image);
# Iterate over each entry in %files
for my $key (keys %files)
{
my $original_name = $files{$key}{name};
my $converted = $original_name;
next unless $original_name;
# These keep Unix filenames at least a little sane
$converted =~ tr/ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_+.!@$%,-/_/c;
$converted =~ s/^\$\.// unless $converted eq '$.';
# Start with the converted value
my $unique = $converted;
# Ensure the converted value is unique across all entries
my $prefix = 0;
while (grep { $_ ne $key && $files{$_}{converted} && $files{$_}{converted} eq $unique } keys %files) {
$unique = $prefix++ . '-' . $converted; # Prefix with '0-', '1-', etc.
}
# Store the unique converted value
$files{$key}{converted} = $unique;
}
foreach (keys %files)
{
my $n=$files{$_}{name};
next unless $n;
next unless $n =~ $filter_regex;
my $c=$files{$_}{converted};
my $file=ExtractFile($image,$n,%files);
my $crc=CalcCrc(\$file);
if ( -e $c && !$overwrite )
{
my $c1=$c;
my $cnt=0;
while ( -e $c1 ) { $c1 = $c . "-" . ($cnt++); }
$c=$c1;
}
print "Saving $files{$_}{name} as $c\n" if $verbose;
my $fh=new FileHandle ">$c";
die "Can not open $c for saving\n" unless $fh;
binmode($fh);
print $fh $file;
close($fh);
$fh=new FileHandle ">$c.inf";
die "Can not open $c.inf for saving\n" unless $fh;
printf $fh "%-9s %6X %6X %sCRC=%04X",
$files{$_}{name},
$files{$_}{load},
$files{$_}{exec},
$files{$_}{locked}?"Locked ":"",
$crc;
close($fh);
}
}
sub add_content_to_ssd($$$$$$;$)
{