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Re: IIc + SmartPort behavior



On 11/07/2011 12:07 PM, Peltier Cedric wrote:
Le 07/11/2011 13:54, Steven Hirsch a écrit :
On 11/06/2011 11:36 PM, Michael J. Mahon wrote:
Steven Hirsch<snhirsch@gmail.com> wrote:

At this point, the primary issue with IIc+ is that it won't boot the
spvhd. Both the IIgs and IIc+ try to access the spvhd a bit before its
firmware comes ready, so you generally need an immediate Oa-Ctrl-Reset
after powerup. Then, you can do PR#5 and boot from the internal 3.5
diskette. When P8 comes up, as many as three virtual disks will be
recognized (assuming you aren't using an ancient ProDOS 8).

I don't consider this any sort of show-stopper and I'm sure Cedric will
sort out the firmware.

Steve

I'm a bit surprised that it doesn't keep mapping logical devices until it
runs out of mappable slots.

Apple's specs claim support for a total of (4) devices on the Smart bus.
That limit appears to be real.


Initialy the SPVHD was limited to 4 virtuals drives, but I pushed this limit
up to 10 virtuals drives after a discussion with Geoff Weiss. Prodos 8 2.0.3
seem to be able to map more than 4 devices using all available slots.
Nevertheless, some 8 bits applications don't handle nicely so much devices.
The devices limitation should be correlated with electrical limitation at the
time, and I suppose the maximum number of devices that Prodos 8 can handle
evolved to follow hardware evolutions.

The IIc+ Specifications on Apple web site (archives) state:

".. allows a daisy-chain connection of up to three additional drives (Apple 3.5, Unidisk 3.5 or Apple 5.25)"

I'm guessing the firmware simply never polls for anything more than (3) attached disks.

Steve