ImageDisk 1.08 posted

[Tony Duell]

> 
> On 11/21/2005 at 7:20 PM ard at p850ug1.demon.co.uk wrote:
> 
> >I do have the HP150 technical reference manual and the 150-II update, but 
> >from what I rmemeber it says remarkably little about the physical disk 
> >format. I wrote linus programs to read the 9114 disks and there was 
> >nothing of use in said manual.
> >
> >>From what I recall, the single and double sided formats are 
> >somewhat different, though.
> 
> A long time ago, I wrote a DOS driver for the HP-150 series 1 and 2.
> Here's what I have:
> 
> HP-150 series 1:
> 
> 	16 256-byte sectors per side, 1 side, 66 cylinders, interleaved 4:1, first
> sector is 1

That sounds possible. It agrees with the technical mamual, I think

The manaul gives remarkable little info on the disk format, as I said, 
because the 150 itself doesn't bother with it -- it's handled by the HPIB 
drives units. But it does give the follwoing. I will correct the obvious 
errors (it firstly talks about 3" disks when they clearly mean 3.5", and 
it claims the single-sided units have 2 heads (!)). Anyway :

3.5" Single sided : 

Bytes/sector = 256

Sectors/track = 16

Heads = 1

Total Sectors = 1056

That implese 66 tracks (or cylinders)


3.5" Double sided : 

Bytes/sector = 512

Sectors/track = 9

Heads = 2

Total sectors = 1386

Which gives 77 cylinders. Note that the values in the HP150 (original) 
manual seem to be full of errors!

> 
> HP-150 series 2:
> 
> 	9 512-byte sectors per side, 2 sides, 77 cylinders, interleaved 2:1, first
> sector is 1


Of course seiris 1 and series 2 here have nothing at all to do with the 
HP150 and the HP150-II specificially. Any HP150 (AFAIK) cna take either 
single or double sided drive.

And an HP LIF format disk has 16 256-byte sectors/track (32 per cylinder 
on a double-sided unit, like a 9114).


-tony