TrsDos.rb in ripxplore-0.0.2

- old
+ new

@@ -5,11 +5,12 @@
 	$:.include?(File.dirname(__FILE__+"\\..")) || $:.include?(File.expand_path(File.dirname(__FILE__+"\\..")))
 
 
 require 'FileSystem'
 #TRSDOS (and compatables, e.g. LDOS, NEWDOS)
-#Reference - http://www.classic-computers.org.nz/system-80/software-manuals/manuals-NewDOS-80_v2.0_manual.pdf pages 99-101
+#Reference - http://www.fileden.com/files/2008/7/6/1990698/manuals-NewDOS-80_v2.0_manual.pdf pages 99-101
+#(previous location -  http://www.classic-computers.org.nz/system-80/software-manuals/manuals-NewDOS-80_v2.0_manual.pdf )
 #sectors 2-9 of the directory track (17) contain File Primary Directory Entries, which are 32 bytes made up of:
 # byte $00: 
 #     bit 7 : 0 = FPDE, 1 = FXDE
 #     bit 6 : 1 means a SYSTEM file
 #     bit 5 : undefined
@@ -64,13 +65,13 @@
 #for now, only SSSD images are supported
 def self.sectors_per_granule(file_system_image)
   5
 end
 
+#all TRS-80 disks seem to start with the same bytes
 is_valid_file_system_if lambda {
-  file_system_image.image_format.instance_of?(Trs80Jv1Dsk)
-}
+  file_system_image.get_sector(0,0)[0,3]==[0x00,0xFE,0x11].pack("CCC") }
 
 FDE_SIZE=0x20
 
 def self.files(file_system_image)
   files=FileContainer.new
@@ -86,11 +87,11 @@
       #for a valid FPDE, bit 7 is 0 and bite 4 is 1
       is_fpde  = ((attributes & 0b10010000)==(0b00010000))
       next if !is_fpde 
       eof_low=fde[0x03]
       filename_base=fde[0x05,8].unpack("A8")
-      filename_extension=fde[0x0D,3].unpack("A8")
+      filename_extension=fde[0x0D,3].unpack("A3")
       filename="#{filename_base}/#{filename_extension}"
       contents=""
       eof_mid=fde[0x14]
       eof_high=fde[0x15]
       file_length=(eof_high<<16)+(eof_mid<<8)+eof_low
@@ -100,13 +101,15 @@
 # byte $16 - $1F : 5 pairs of extent elements, each pair made up of:
 #     byte $00 : if $FF, then end of extent elements for this file. if $FE, then next byte contains the DEC for the first (or next) FXDE assigned to this file.
 #                     any other value ($00-$FD) equals the number of the diskette's lump in which the area starts. 
 #     byte $01  : bits 7-5 = number of granules (0-7) from the start of the lump to the start of the area
 #                   : bits 4- 0 = number less one of contiguous granules assigned to this area.
+
       5.times do |extent_no|
         extent=fde[(extent_no*2)+0x16,2]
         break if extent[0]==0xFF
-        raise "FXDE's not implemented yet" if extent[0]==0xFE
+        #raise "FXDE's not implemented yet" if extent[0]==0xFE
+        break if extent[0]==0xFE # "FXDE's not implemented yet"
         track_no=extent[0]
         granule_offset=extent[1]>>5
         number_of_granules=1+(extent[1] & 0b00011111)
         start_sector=granule_offset*sectors_per_granule(file_system_image)
         number_of_sectors=number_of_granules*sectors_per_granule(file_system_image)