Changes
| 12..15 || Zero || Contains all zeroes
|-
| 16 || Block number || Tape only, set to 0
|-
| 17 || Last block || Tape only, set to 0
|-
| 18 || File type || 0:BASIC 1:Protected 2:Binary (ASCII files don't have headers but a fake header is built in memory with the file type #16, "Unprotected ASCII v1")
|-
| 19..20 || Data location length || Address of the 2KB bufferAs per cassette
|-
| 21..22 ||Load address Data location || As per cassette
|-
| 23 || First block || Set to #FF, only used for output files
|-
| 24..25 ||style="white-space: nowrap;"| Logical length || Actual file length is here
|-
| 26..27 || Entry address || As per cassette
|-
| 28..63 || Unused ||
| 67..68 || Checksum || Unsigned sum of all bytes until this field
|-
| 69..127 || Unused || Free to use
|}
