Changes
Bits1..3 = File contents (0:BASIC, 1:Binary, 2:Screen image, 3:ASCII, 4..7 are unallocated)
Bits4..7 = Version(ASCII files should be version 1, all other files should be version 0)
|-
| 19..20 || Data length || The number of data bytes in the data record. As per cassette
