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CBM900_HD_EMU.BIN

Metadata

   BitStore.Metadata_version:
   	1.0
  
   BitStore.Access:
   	public
  
   BitStore.Filename:
   	CBM900_HD_EMU.BIN
  
   BitStore.Size:
   	51369720
  
   BitStore.Format:
   	BINARY
  
   BitStore.Ident:
   	30001200:1
  
   BitStore.Digest:
   	sha256:d591176c405d582f73211a0d928e489e498cfc00eb0ec111ce49997608bb0caa
  
   BitStore.Last_edit:
   	20200222 phk
  
   DDHF.Keyword:
   	CBM900
  
   Media.Summary:
   	Commodore 900 hard "bit transition" disk image
  
   Media.Type:
   	ST506 Disk
  
   Media.Model:
   	MiniScribe 3425
  
   Media.Serial:
   	MS III 280042
  
   Media.Description:
   	This object is a "bit transition file" from David Gessweins
   	"MFM-emulator" device.  For more information see:
   	
   		http://www.pdp8.net/mfm/mfm.shtml
   	
   	This is a non-standardized file format, but given the CMB900's
   	uniqueness, we judge this to be the best format for preserving
   	a "forever" reproducible image of the hard-disk.
   	
   	This file can either be used to emulate a hard-disk in the
   	CBM900 with Davids hardware (we have tried this, it works)
   	or to format/write a harddisk which the CBM900 can use
   	(this we have not tried yet).
   	
   	The MFM emulator auto-detects the following information about
   	the CBM900 harddisk:
   	
   		--format Intel_iSBC_214_512B \
   		--sectors 17,0 --heads 4 --cylinders 616 \
   		--header_crc 0xffff,0x1021,16,0 \
   		--data_crc  0xffffffff,0x140a0445,32,5 \
   		--sector_length 512 --retries 50,4 --drive 1
   	
   	The "Intel_iSBC_214_512B" format may, or may not, be at odds
   	with the fact that the harddisk controller uses a WD1003 chip.
   	
   	The MFM-emulator software can be found at:
   	
   		https://github.com/dgesswein/mfm
   	
   	The format of "transition files" is documented in the source file
   	emu_tran_file.c as follows:
   	
   	// Transition file header format. See code for which fields are present
   	//    in which file version.
   	//    uint8_t[8] File id string 0xee 0x4d 0x46 0x4d 0x0a 0x1a 0x0a 0x0d
   	//    uint32_t File type and version. Current 0x01020200
   	//    uint32_t Offset to start of first track header in bytes.
   	//    uint32_t Size of the header portion of each track in bytes.
   	//    uint32_t Number of cylinders of track data in file.
   	//    uint32_t Number of heads/tracks of data per cylinder.
   	//    uint32_t Transition count rate in Hz. Only 200 MHz currently supported.
   	//    uint32_t Length of command line used when capturing.
   	//    uint8_t  Command line used when capturing. Zero terminated.
   	//    uint32_t Length of note option.
   	//    uint8_t  Note option text. Zero terminated.
   	//    uint32_t Start time of data from index in nanoseconds.
   	//    uint32_t Checksum of header. Calculated over bytes using crc64 in
   	//       this program suite. Polynomial 0x140a0445 length 32 initial value
   	//       0xffffffff.
   	//
   	// Transition file track header format 
   	//    int32_t Cylinder number of track
   	//    int32_t Head number of track
   	//    uint32_t Number of bytes of transition data
   	//    uint32_t Checksum of header and track data. Calculated over bytes 
   	//    using crc64 in this program suite. Polynomial 0x140a0445 length 
   	//       32 initial value 0xffffffff.
   	//    Cylinder and head of -1 indicate no more data.
   	//
   	// Transitions are count of clocks between one bits stored as bytes.
   	//    A transition of 255 indicates the next 3 bytes are a 24 bit transition
   	//    value. A transition value of 254 indicates the next 2 bytes are a 16
   	//    bit transition value. Otherwise the transition count is a single byte.
   	//    Clock transition count clock frequency is in file header. For 200 MHz
   	//    a count of 40 indicates 5 MHz pulse spacing.
  
   *END*

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