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Re: DMA 4 meg v. 8 meg
On 7 mai, 15:28, schmidtd <schmi...@my-deja.com> wrote:
> On May 6, 5:34 pm, "Michael J. Mahon" <mjma...@aol.com> wrote:
>
> > OK, now I'm confused. ;-)
>
> > ProDOS *always* maps "extra" block storage partitions to other
> > slots, since each slot has only two logical "drives", right?
>
> > And any slot not containing a _physical_ block storage device can
> > be used as the "name" of two _logical_ block storage partitions.
>
> > So are you talking about something different, or is the new CFFA
> > mapped by ProDOS totally differently from the old one?
>
> No, sorry - now I've managed to confuse experts and non-experts
> alike. And I'm not an expert of ProDOS drive/name placement - I just
> report what I observe. Clearly I need to come up with a better way of
> explaining this. :-) It's all the same as before. There's no new
> rules in place; just new opportunities to insert drives, and now a new
> virtual Disk II adapter with its two attendant drives.
Hello,
I understand from David's message that it is easy to add new devices
with the new CFFA, you select the image, it finds the first free room
in ProDOS' device allocation table.
-------
As far as ProDOS is concerned...
Please, refer to P8 technotes: 53, 54, 65
ProDOS device recognition routines are two-folded:
- first pass checks for Disk IIs
- second pass checks for SmartPort devices
The routines also checks what's in slots 2 (the IIgs ramdisk goes
there), 3 (80-col card) and 5 (smarport device of the IIgs) then it
goes from slot 7 to slot 1 and allocates devices (depending on the
number of drives attached per device) in the following order:
dc.b $06 ;slot 3 drive 1
dc.b $1E ;slot 7 drive 2
dc.b $0E ;slot 7 drive 1
dc.b $1C ;slot 6 drive 2
dc.b $0C ;slot 6 drive 1
dc.b $1A ;slot 5 drive 2
dc.b $0A ;slot 5 drive 1
dc.b $14 ;slot 2 drive 2
dc.b $04 ;slot 2 drive 1
dc.b $12 ;slot 1 drive 2
dc.b $02 ;slot 1 drive 1
dc.b $18 ;slot 4 drive 2
dc.b $08 ;slot 4 drive 1
The physical order is different from the logical one. That's for sure
from what I've read.
Antoine