Class: AppleCPM

Inherits:
FileSystem show all
Defined in:
lib/file_systems/AppleCPM.rb

Constant Summary collapse

RECORD_SIZE = 
128
BLOCK_SIZE = 
1024
BLOCKS_PER_EXTENT = 
16
RECORDS_PER_BLOCK = 
BLOCK_SIZE/RECORD_SIZE
RECORDS_PER_EXTENT = 
RECORDS_PER_BLOCK*BLOCKS_PER_EXTENT
SECTORS_IN_BLOCK = 
[
  [0x00,0x06,0x0C,0x03],  #block 0
  [0x09,0x0F,0x0E,0x05],  #block 1
  [0x0B,0x02,0x08,0x07],  #block 2
  [0x0D,0x04,0x0A,0x01]  #block 3
]

Class Method Summary collapse

Methods inherited from FileSystem

all_file_systems, code_for_tests, compatability_score, is_valid_file_system_if, non_matching_score

Methods included from SubclassTracking

extended

Class Method Details

.files(file_system_image) ⇒ Object

CPM DIR looks like this: $00 User number, or E5h if it’s a free entry $01..0B Filename + extension: 8+3 characters $0C..0D Extent number of this entry $0E ??? $0F Number of 128-byte records allocated in this extant $10..1F Allocation map for this directory entry



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# File 'lib/file_systems/AppleCPM.rb', line 72

def self.files(file_system_image)
  files=FileContainer.new
  catalog=get_block(file_system_image,0)+get_block(file_system_image,1)
  0.upto(63) do |dir_entry_no|
    dir_entry_start=dir_entry_no*0x20
    dir_entry=catalog[dir_entry_start..dir_entry_start+0x1F]      
    if (dir_entry[0]<0x10) then
      file_name=dir_entry[0x01..0x08].gsub(' ','')
      file_ext=dir_entry[0x09..0x0B].gsub(' ','')
      full_filename="#{file_name}.#{file_ext}"
      files<<NativeFileType.best_fit(file_system_image,full_filename,'',file_ext)
      if files[full_filename].nil? then
        files<<file 
      end
      s=""
      0x10.upto(0x1f) do |i|
        block=dir_entry[i]
        s+=get_block(file_system_image,block) unless block==0
      end        
      records_allocated=dir_entry[0x0F]
      files[full_filename].contents+=s[0,(records_allocated*128)]
    end
  end    
  files
end

.get_block(file_system_image, block_no) ⇒ Object 



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# File 'lib/file_systems/AppleCPM.rb', line 32

def self.get_block(file_system_image,block_no)
  track_no= ((block_no/4)+3)%file_system_image.track_count
  s=""
  SECTORS_IN_BLOCK[block_no%4].each {|sector_no| s+=file_system_image.get_sector(track_no,sector_no)}
  s
end

.host_system ⇒ Object 



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# File 'lib/file_systems/AppleCPM.rb', line 11

def self.host_system
  Apple2
end

.matching_score ⇒ Object 



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# File 'lib/file_systems/AppleCPM.rb', line 15

def self.matching_score
  20
end