Update of ILper to v2.21

[Christoph Giesselink]

Just a small update of ILper to v2.21 available at http://hp.giesselink.com.

Two month ago Jean-Francois was analysing how the HP41 create directory entries on a LIF disk. During his tests he also was working with a real HP9914 disk drive, initializing the disk media and write data to it.

Comparing the data written to a real disk inside a HP9114 and the virtual disk inside ILPer 2.2 he noticed a difference. The real disk contain a LIF version number of 1, a valid number of tracks per surface, number of surfaces and number of blocks per track, whereas these positions are filled with 0 in the virtual disk inside ILPer.

For sure, the HP41 don't write this data onto the disk inside the HP9114, so the HP9114 must do this by himself when writing the sector 0 information like the fix for the HP82401A rev. 1A module.

ILPer 2.21 contain this fix for the HP41 also now. The fix is using the actual media configuration of the drive.

So the difference between a virtual disk initialized with a HP-71B or a HP41 is the volume label and the initialization date and time. Both, the label and the date, time are not set by the HP41.

So what are the consequences using HP41 initialized virtual disks with LIF Version 0 in connection with ILPer 2.21? In general reading and writing will work as before, the only difference is when you rewrite sector 0. For the HP71 exists for example a program allowing to modify the volume label of the disk, this is a write access to sector 0 and so the fix for the HP41 initialized media become active and will update the LIF version and the media dimension data.

But be aware, when you "inserted" such a disk image into a high capacity drive and force writing sector 0, the disk will be initialized with the high capacity data!