7 Dec
2010
7 Dec
'10
11:40 a.m.
If the geometry is really a mystery (I don't think it is), I do have
a program I wrote some years back to determine the geometry of any
drive, IDE, ESDI or MFM/RLL. The former two by issuing an IDENTIFY
command; the latter by a binary-search type of approach. As long as
the MFM drive is formatted and readable, I can determine the actual
I seem to remember that some/most/all ST412-interfaced drives will assert
an error signal if you select a head that isn't present (e.g. selecting
head 6 on a 6-head (numbered 0 to 5) drice) or if you seek heyond the
maximum cylinder. I've worked on several systems that use this to make
sure the hard drive is the one they're xonfigured for and complain if it
isn't (even it it haas more heads/cyliunders than are expected).
Can you use something like that on a normal PC controller?
geometry--it uses direct I/O port access (either PC/XT
or AT-style
controllers) and does not rely on the BIOS.
(With a nod in Tony's direction) This obviously is for PCs and
compatibles, sorry.
Err, yes :-). While I have seen PC controller cards used in machines
that are certainly not PCs, I would have guessed from yuour mention of
PC/XT and PC/AT controllers that your program runs on a PC.
-tony