Re: ProDOS / Autostart ROM ID bytes

[dempson@actrix.gen.nz (David Empson)]

mdj <mdj.mdj@gmail.com> wrote:

> David Wilson wrote:
> 
> > Well spotted. Unfortunately this is the original Workbench ProDOS
> > manual and you cannot believe all you read in it.
> >
> > e.g. Page 113 - In reality, only slot 5 supports 3-4 drives and they
> > end up in slot 2.
> 
> At least in versions of ProDOS prior to 2.0.1 anyway.

Also of note: the ProDOS block driver mechanism for slot 5 drive 3 or 4
(remapping to slot 2 if it isn't occupied by a disk controller) was
added in ProDOS-8 1.2. It only works if the card is slot 5 is able to
cope with the "wrong" slot appearing in its unit number.

> The last release remaps devices beyond 2 on any slot to the remaining
> free slot/drive positions.

... but it only does this for devices which support the SmartPort
firmware interface, and doesn't make use of any spare drive 2 unit
numbers where drive 1 is mapped to a real device. For example, a
"slinky" RAM card in slot 4 would use S4,D1, but nothing will be
allocated to S4,D2.

All of Apple's late model intelligent multi-drive controllers support
SmartPort, so they can take advantage of this feature: Liron card,
Superdrive card, IIc and IIgs slot 5 firmware, original SCSI card
(limited to 7 drives or partitions), high-speed SCSI card.

Standard slot RAM cards also commonly support SmartPort. I know that
Apple's card does, but it only has a single logical volume. Not sure
about the AE RAMFactor or PC Transporter.

Third party support for SmartPort is more spotty. For example, the
RamFast SCSI card doesn't support it, but has its own method of patching
multi-unit support into ProDOS's device table.

I don't recall other third-party cards with Smartport support, but I'm
sure there are some. Anyone else?

-- 
David Empson
dempson@actrix.gen.nz