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== Data on Cumana disk System Track ==
|Byte      |Use                                            |
|0         |Drive 0, side 1 - Number of tracks (0, 40, 80) |
|1         |Drive 1, side 1                                |
|2         |Drive 2, side 1                                |
|3         |Drive 3, side 1                                |
|4         |Drive 0, side 2                                |
|5         |Drive 1, side 2                                |
|6         |Drive 2, side 2                                |
|7         |Drive 3, side 2                                |
|8         |DSTEP value                                    |
|9 - F     |                                               |
|10        |Sector for next available sector               |
|11        |Track for next available sector                |
|12        |Sector pointer to first directory              |
|13        |Track pointer to first directory               |
|14 - 15   |Number of blocks free on disk - 2 bytes        |
|16 - 17   |Number of blocks used on disk - 2 bytes        |
|18 - 20   |Disk name                                      |
|21 - on   |Not used                                       |


== Data on Cumana disk Directory Track ==

|Byte      |Use                                               |
|0         |Track - pointer to next directory (0 if no more)  |
|1         |Sector - pointer to next directory (0 if no more) |
|2         |Number of files in directory (max = 15)           |
|          |                                                  |
|3 - 8     |Filename - null if no file in slot                |
|9 - B     |Filename extension                                |
|C - D     |Number of sectors taken by file - 2 bytes         |
|E         |Sector of first block of program                  |
|F         |Track of first block of program                   |
|10        |Sector of last block of program                   |
|11        |Track of last block of program                    |
|12        |P, N, I status                                    |
|          |                                                  |
|13 - 22   |Repeat sequence in 16 byte blocks                 |
|etc.      |Same format for data files, including STORE       |


== Data on Cumana disk File Tracks ==

|Byte      |Use                                                                         |
|          |//First block (program, code, memory created by !SAVE)//                        |
|0         |Track pointer to next block                                                 |
|1         |Sector pointer to next block                                                |
|2         |#FF = suitable for !LOAD                                                    |
|3         |00                                                                          |
|4 - 5     |Start address for !LOAD - 2 bytes                                           |
|6 - 7     |End address for !LOAD - 2 bytes                                             |
|8         |T address / program type - 2 bytes:                                         |
|9         |0000 = code no T, 0001 = basic, 0002 = basic AUTO, ABCD = code T address    |
|A         |Number of bytes in this block.      #F5 = full                              |
|B         |Data bytes from here on                                                     |
|          |//Subsequent blocks created by !SAVE//                                          |
|0         |Track pointer to next block.      Null if no more                           |
|1         |Sector pointer to next block.       Null if no more                         |
|2         |Number of bytes in this block.      #FD = full                              |
|3         |Data bytes from here on                                                     |
|          |//Blocks created by !OPEN / !PUT//                                              |
|0         |Track pointer to next block.      Null if no more                           |
|1         |Sector pointer to next block.       Null if no more                         |
|2         |Data - for single byte data.       For $ - length of $ (e.g. 3) followed by |
|          |string                                                                      |
|3         |Data - for single byte data.       For $ - string character                 |
|4         |Data - for single byte data.       For $ - string character                 |
|5         |Data - for single byte data.       For $ - string character (last)          |
|6         |Data - for single byte data.       For $ - length of $ followed by string   |
|7         |Data - for single byte data.       For $ - string character                 |
|8         |etc.                                                                        |
|          |//Blocks created by !STORE//                                                    |
|0         |Track pointer to next block.      Null if no more                           |
|1         |Sector pointer to next block.       Null if no more                         |
|2 - 3     |End address + 1 from which data was saved - 2 bytes                         |
|4 - 5     |Start address from which array was saved - 2 bytes                          |
|6         |Bit 7 set for % integers                                                    |
|7         |#FF for strings                                                             |
|8         |Array block copied from memory. For $ - Length of $ followed by $.          |
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