Re: Apple II slot assignments

[david@wraith.cs.uow.edu.au (David E A Wilson)]

dempson@atlantis.actrix.gen.nz (David Empson) writes:
>The rules applied by ProDOS-8 2.0 and later are as follows.

>1. /RAM (auxiliary memory 64K ram disk) always appears in S3D2,
>   unless a program has currently disabled it.

Correct.

>2. Real devices use drive 1 and 2 of the slot in which they live.

Correct.

>3. If there are any devices which support the "SmartPort" firmware
>   interface, and have more than two devices available, then ProDOS-8 will
>   remap them into unused slot/drive positions.  For the purposes of this
>   remapping, only disk I/O devices (5.25" controller or cards with a ProDOS
>   driver) are considered.

You missed step 2 and a half:

2.5. If a Smartport with more than 2 block devices is found in slot 5 then
     drive 3 will map to S2D1 while drive 4 (if present) will map to S2D2.

>   All of the remapped devices are handled by a driver provided within the
>   language card by ProDOS, which converts the ProDOS driver call into
>   a SmartPort call, and routes it to the appropriate slot.

This is the case for all remapped drives except for those dealt with in step 2.5
as all Smartport cards that support > 2 drives must handle the slot 2 -> 5
remapping themselves. This works for P8 v1.2+ instead of only P8 v2.x.

>   I'm not sure what rules are followed by the remapping.  In your
>   case, it appears that the third device from your disk port (smartport)
>   has been remapped as S4D1, and six SCSI partitions would be remapped
>   as S1D1, S1D2, S3D1, S4D2, S7D1 and S7D2.

The rules are fairly simple:

a) Slot/Drives are used in the following order:

	S4D1, S4D2, S1D1, S1D2, S2D1, S2D2,
	S5D1, S5D2, S6D1, S6D2, S7D1, S7D2,
	S3D1

This can be seen from the lookup table at $2909 in P8 v2.0.3.

b) If a slot has a block device controller in it then no devices can be
   mapped to unused drives for that slot. ie: a Slinky RAMcard has 1 drive
   but no other Smartport drive can be mapped to that slots drive 2 position.
-- 
David Wilson	Dept CompSci Uni Wollongong Australia	david@cs.uow.edu.au