22 Nov
2005
22 Nov
'05
9:12 p.m.
On 11/21/2005 at 7:20 PM ard at p850ug1.demon.co.uk wrote:
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!
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.
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 From what I recall, the single and double sided
formats are
somewhat different, though.
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