Re: floppy disk change (was Re: 1.15 kernel)

[Konrad Kokoszkiewicz <draco@mi.com.pl>]

> > Yes, perhaps it is not good considering speed, but so far I haven't heard 
> > about any other proposition (for ST and TT TOS).
> 
> OK - I talked about this with Uwe and we came up with a possible solution.
> 
> The problem really is that the BIOS won't see a change in the write protect
> line when write protected disks are swapped. A possible solution would be to
> install some kind of 'floppy-idle-loop' which does a 'read ID' (or whatever
> the command is called on the 1772) whenever there is no other command
> pending for the 1772 (or for the ST-DMA). When you do not get a sector ID
> for 1 disk rotation, you either have an unformatted track or the disk was
> removed, so you can set the 'maybe changed' flag.
> 
> After a timeout of some seconds, the motor is stopped as usual. When turning
> it back on, we have to set the 'mayba changed' flag, too.

Sounds logical. I don't remember the 1772 well (it has been a while since
I'd played with this chip), but won't the "read id" command prevent the
motor from stopping? FDC is pretty simple, that I remember, but I don't
know...

> > Yes, I realize that and I think I personally could pay that price.
> 
> I would rather press ESC after switching disks and have decent speed
> instead (you have to press ESC anyway - neither the desktop nor Gemini read
> in a changed disk automatically, so the only difference is whether to do a
> normal re-read or a forced diskchange).

YES. Definitely, it would be the best if both solutions could be made
together: i.e. some "guessing" from sector id loop and motor state, plus
ESC as instant forced change.

Plus some "esc-emulator" for weird people using their Atari via 
telnet (like I do :-)).

> If you want it *really* fast, you could connect a button to the write
> protect signal to manually cause the BIOS to recognize the disk change. I
> wonder if it might be possible to do this automatically when a disk is
> changed with some small logic circuit ... 

No, that's a bit of exaggeration I guess. :-)

--
Konrad M.Kokoszkiewicz
|mail: draco@mi.com.pl                  | Atari Falcon030/TT030/65XE |
|http://www.orient.uw.edu.pl/~conradus/ | ** FreeMiNT development ** |

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