DSK format: Difference between revisions

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DSK format (view source)

Revision as of 12:36, 13 December 2022

161 bytes added ,  13 December 2022
→‎Track data
Line 85: Line 85:


For each track:
For each track:
* 00-0b "Track Info\r\n"
 
* 0c-0f unused
{| class="wikitable"
* 10    Track number
! byte
* 11    Side number
! notes
* 12-13 unused
|-
* 14    Sector size (1=256, 2=512, 3=1024 ect)  
|00-0b  
* 15    Number of sectors  
|"Track Info\r\n" - Track header
* 16    Gap#3 length
|-
* 17    Filler byte
|0c-0f  
|unused
|-
|10     
|Track number
|-
|11     
|Side number
|-
|12-13  
|unused
|-
|14     
|Sector size (1=256, 2=512, 3=1024 ect)  
|-
|15     
|Number of sectors
|-
|16     
|Gap#3 length
|-
|17     
|Filler byte  
|}


Next from 18 onward of the track info, is the sector list information.
Next from 18 onward of the track info, is the sector list information.
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There are 8 bytes per record
There are 8 bytes per record


* 00    Track (Equivalent to "C" parameter in the 765 FDC)
{| class="wikitable"
* 01    Side  (Equivalent to "H" parameter in the 765 FDC)
! byte
* 02    Sector ID (Equivalent to "R" parameter in the 765 FDC) (These are 1-9 for +3 disks, Others use $40-49 and $C0-C9)
! notes
* 03    Sector size  (Equivalent to "N" parameter in the 765 FDC) should be the same as #14 above
|-
* 04    FDC status register 1 after reading
|00     
* 05    FDC status register 2 after reading
|Track (Equivalent to "C" parameter in the 765 FDC)  
* 06-07 Actual data length of the sector in bytes (EXTENDED only), 00 otherwise [1]
|-
|01     
|Side  (Equivalent to "H" parameter in the 765 FDC)
|-
|02     
|Sector ID (Equivalent to "R" parameter in the 765 FDC) (These are 1-9 for +3 disks, Others use $40-49 and $C0-C9)
|-
|03     
|Sector size  (Equivalent to "N" parameter in the 765 FDC) should be the same as #14 above
|-
|04     
|FDC status register 1 after reading
|-
|05     
|FDC status register 2 after reading
|-
|06-07  
|Actual data length of the sector in bytes (EXTENDED only), 00 otherwise [1]
|-
|}


[1] Note, bytes 6 and 7 this is used for some forms of copy protection where the written sector is smaller than the requested sector.  These copy protection methods rely on the FDC returning an error, so they may request a sector of 512 bytes, but the actual data on the disk is only (Say) 200 bytes.  
[1] Note, bytes 6 and 7 this is used for some forms of copy protection where the written sector is smaller than the requested sector.  These copy protection methods rely on the FDC returning an error, so they may request a sector of 512 bytes, but the actual data on the disk is only (Say) 200 bytes.  
Line 113: Line 155:
At the next $100 boundary, the actual data starts.
At the next $100 boundary, the actual data starts.


this is just a stream of data for each sector in the same order and with the same size as the data above.  
this is just a stream of data for each sector in the same order and with the same size as the data above.


==Example==
==Example==
Spodula
90

edits

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