Re: Apple II IDE interface

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

St�phane Guillard <stephane.guillard@steria.com> wrote:

> Hi all,
> 
> I've designed a very simple but fully functional IDE interfacefr Apple II's.

[snip]

> I try to keep the software as small as possible and relocatable, so that it
> can be loaded both with old DOS3.3 or ProDos, and let you transfer files
> from floppies to HD and back. I guess there also could be some interest in
> making a complementary patch which would make the file access go to HD from
> normal DOS or ProDos calls, so that software using DOS API can work with the
> HD. I will look at it later. I don't intend to make a ProDos block driver,
> as this would limit the use of the HD to 2x30 MByte partitions, and would
> not be compatible with other platforms.

A ProDOS block driver (preferably in ROM on the card, to avoid having to
load any patches) would allow the card to work automatically with
ProDOS-8, GS/OS and Apple II Pascal 1.3, with the catch that you are
limited to two 32 MB partitions, as you mentioned.

An even better option: write a SmartPort block driver in firmware on the
card.  This will allow ProDOS-8 2.0.x to access up to 10 or so
partitions (depending on the contents of other slots) and would allow
GS/OS to access multiple and larger volumes.

I suspect that having either a ProDOS driver or a SmartPort driver would
require adding some RAM to the card, so the firmware can store
information about the partitions detected on the drive(s).

The ultimate option: also write a native GS/OS driver, allowing GS/OS to
get much better performance when accessing the drive.


On the other hand, there are already other IDE cards out there which
have these features (notably the Focus), so it would be rather a lot of
work for a limited user base.