Re: disk image emulator on the GS - possible?

[Toinet <antoine.vignau@laposte.net>]

On 2 juil, 01:52, "Charlie" <charlieD...@verEYEzon.net> wrote:
> "Toinet" <antoine.vig...@laposte.net> wrote in message
>
> cc928f2a-ebb1-4549-9345-0aa5a2d46bfb@z14g2000yqa.googlegroups.com">news:cc928f2a-ebb1-4549-9345-0aa5a2d46bfb@z14g2000yqa.googlegroups.com...
>
>
>
>
>
> > Hi All,
>
> > I like that post, I worked on such a IIgs thing in January 2009 in
> > order to mount CBM D64 images.
>
> > The objective is to double-click a disk image (DSK, PO) and thanks to
> > the IPC thing in a PIF, load the file into memory, perform the
> > necessary checks and add it into the list of devices.
>
> > What is interesting is that the driver is responsible for the
> > different block reads and writes or inits and that's all, the rest of
> > the job is performed by the FSTs.
>
> > I developed that new driver with my source code of the RAM5 (works
> > with the RAM but is firmware related) and ensoniqRAM (not hardware
> > related) drivers but I failed as I am still unable to simulate the
> > disk insertion or ejection which would update the device list, even
> > with the help of the different GS/OS books.
>
> > If one understands that notion (how to mount/unmount a device), please
> > contact me and I will finish that one during my summer vacation,
>
> > antoine
>
> Hi Antoine,
>
> I'm really glad you jumped into this discussion since I feel I was
> getting in way over my head.
> It seems you are very close to what the original poster wanted.
>
> First I have to say that I've never done any device driver programming
> for the Apple IIgs. Since I don't want anyone to think I would let my
> ignorance stop me from posting I'll ask if you have tried using the
> system service call SET_DISKSW which is supposed to notify GS/OS that a
> disk switched or is in an off-line condition.  If I understand the
> description of the call (page 283 of the device driver reference)
> drivers can request a change in the disk switched status which is
> maintained by the device dispatcher.  I believe the device dispatcher is
> responsible for the device list.
>
> Anyway the description sounds a lot like what you want so I had to ask.
>
> Charlie

Thanks for your help, I appreciate. SET_DISKSW requires a device
number which I do not have as I need to let it be set by the device
dispatcher.

Then, I have had an idea: browse the contents of your Apple II
Developer CDs and the answer is to be found here: cd1 / System 6.0
sample code / System 6 pieces / SCSI.Drivers / SCSI Driver Mgmt

The way the Apple SCSI driver works is described hereafter: have a
default empty Device Independent Block and set it as not HW related.
That's all.

When a DStatus or DInfo is performed, control is passed to a routine
(unit_state) which creates DIBs dynamically depending on the
physical / logical volumes present on the device.

Consider now that we are in the FinderExtension, we have just double-
clicked the disk image we want to add to the system, we need to tell
our driver that a new device (then volume if recognized) must come
online. That can be done of two different ways:
- call a subcall to the driver and tell it to add the volume and make
it online (if not already in the devices)
- perform like IR from M. Deatherage does: InitialLoad2 a new driver,
set the interesting values and call it

And the volume will come online because of the SET_DISKSW call that
will be performed!

Oh, I think I will enjoy my summer holidays!

antoine