Subject: Re: Floppy driver (was: Re: This week's NetBSD/amiga changes)
To: Ty Sarna <>
From: None <>
List: amiga-dev
Date: 04/11/1994 10:19:55
> In article <9404110211.AA20743@sun> (Brad Pepers) writes:
> > I myself would vote against saying all amigas have an internal drive. There
> > should be absolutely no reason to make such an assumption. The reason for
> > it is the code to get the floppy type isn't working right. I think its a
> > problem with gcc over optimizing the code. I have sent new assembly code
> > to Chris to try out. I hope when this is working the assumptions can be
> > removed.
> I would like to see support for the 1020 5.25" floppy drive -- it's very
> handy for interchange of MS-DOS floppies with old 5.25" only systems
> (yes, I know it doesn't do MS-DOS format yet, but someday...).  I assume
> that since the floppy driver doesn't support or care about diskchange
> (right?) that the only change neccesary would be to add a line to the ID
> table with the proper information. 
> Hmmm... looking through the Hardware RKM, I can't ind an ID defined for
> the 5.25" drives, unless it's one of the Reserved values. I guess when I
> update to the current sources I'll have to see what it ID's as, if
> anything. If it doesn't ID itself, there will have to be some way for a
> user program to tell the driver that a drive is present and tell it the
> various parameters.
	Another data point:

	The AMIX floppy driver, which support 720K, 880K, 1.44M formats
	and ALOT of "magic" and "juju" comments in it and twiggles and
	frobnicates many mysterious registers above and beyond what the
	code in -current does. It also has a "helper" process that ends
	up being a kernel process, i.e. it's a user mode daemon that
	starts up and does an open on a special device minor that then
	forces it to remain in kernel mode where it services delay timeouts
	and other housekeeping functions. My guess it is an attempt to
	emulate track.device.

	Anyways, it would appear there are more bits the floppy driver
	needs to frob in order to work right. Anybody know if any of
	the old AMIX hackers are still floating around? Maybe they
	could explain the weirdness in the AMIX floppy driver.

	The AMIX driver is rock solid and supports both low density and
	high density drives although it doesn't appear to support 5-1/4".