Re: INIT a hard drive - question

[dempson@actrix.gen.nz (David Empson)]

In article <BIxV57K.dannyjones@delphi.com>,
Danny  <dannyjones@delphi.com> wrote:
> One fellow responded by email to me about my query regarding software to
> initialize a Sider hard drive (20 meg) that has the ATS all-ProDOS ROM chip.

This is only a theory - I've never even seen one of these, let alone
formatted one.

If the card has a ProDOS driver in the ROM (i.e. you don't need to
apply any patches to ProDOS for it to recognise the card and drive),
then it may include a FORMAT routine, which should be supported by any
major ProDOS application that can format disks (including Copy II+,
Filer, System Utilities and probably ProSel).

You can check whether the card _claims_ to support the FORMAT call by
getting into the monitor and examining location $CnFE, where n is the
slot number.  If bit 3 is set (value is $x8, $x9, $xA, ..., $xF), the
driver claims to support the FORMAT call.

Whether the call actually does anything is another question.  It is
quite possible that it does nothing at all, and the card may not have
any built-in software to do a "low level format", assuming this is
what you actually want.  It might also be implemented but always
return an error, to force the program to avoid formatting the drive.

There is a second requirement: the card must either have the disk
capacity (in blocks) stored in ROM locations $CnFC an $CnFD, or must
return this information from a STATUS call to the ProDOS driver.

> But... I was wondering... what would happen if I used Copy II Plus?
> It has that option to init a drive.  Could it correctly init a 20 meg
> hard drive with out problem?

Provided the card implements the FORMAT call and returns capacity
information, then Copy II+ should be able to format it.  The same
technique is used to format 3.5" disks on the IIgs, for example, and
Copy II+ does this fine.

> P.S.  Another question about that... would TRYING it mess anything up that a
>       proper init couldn't fix?

I doubt it.  If the drive is currently working, then trying to format
it with one of these programs might destroy data on it, especially if
the ProDOS driver in the card doesn't implement the calls properly.
-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand