Question about LIF file Volume Flag/Number

[Martin Hepperle]

The documentation for the LIF format is clear w.r.t. this word.

It contains a flag in the high bit #15 and a file volume number in the lower 14 bits. Therefore a filler bit of 0 is placed at bit position 14.
As the typical files used by calculators and small computers are small and fit onto a single medium, the volume number is usually == 1.
A word of 0x0000 would be invalid. The minimum value should be 0x0001, the first file of a multi-volume file.


My documentation:

// (L flag) and (volume number) typically == 0x8001
// L - Last Volume Flag (1 bit)
// If the last volume flag (L) = 0, it is not the last volume of the
// file.
// If the last volume flag (L) = 1, it is the last volume of the file.
volinfo = (1 << 15) | 1;


Official Documentation e.g.:

HP64000 Logic Development System
Flexible Disk Drive Reference Manual
64941-90906, January 1983

[...]

16-bit word at offset 13d:
[L (1 bit) - volume number (15 bits)]

L - Last Volume Flag (1 bit)
If the last volume flag (L) = 0, it is not the last volume of the file.
If the last volume flag (L) = 1, it is the last volume of the file.

Volume Number (1 filler bit + 14 bits)
This is a 14-bit unsigned integer containing the volume number of this file on this medium.
Volume number = 0 is not a valid condition. All files must be contained on at least one
volume. Volumes start with number 1 and are incremented by one for each subsequent volume.

Implementation
Words 14 and 15 are available for implementation dependent uses by file types -2000 to
-77777. These fields must be set to 0 for all interchange file types and for file types -2 to -177.

[...]


Martin