Re: SmartPort Question

[david@uow.edu.au (David Wilson)]

Wayne Stewart <waynes@intergate.ca> writes:
>Bryan Parkoff wrote:
>> 
>> SmartPort Question
>> 
>>     I learn that Apple IIgs Reference book says that SmartPort will support
>> printer, modem, network, etc near the future, but it does not exist.
>>     It also says that it can support up to 127 SmartPort devices.  I suspect
>> that it can only limit to 14 devices under ProDOS 8 because it uses slot 1
>> through 7.  If it is true that ProDOS 16 supports up to 16 devices per slot.
>> Please advise.

>If your IIgs is running GSOS then all those devices don't have to be
>mapped 
>to slots. While technically you can have that many devices, the disk
>port is 
>limited by the power it can supply. I think Apple recommended a maximum
>of 4 
>devices. I used to use 5 when I was installing System 6 on a HD to avoid 
>disk swapping. After I bought a CD burner I made up an installer CD.

Note that Smartport has two meanings:

1) The firmware interface used by SCSI cards, RAMdisk cards and 3.5" floppy
controllers etc.
2) The hardware bus which is only used by 3.5" disk drives.

The firmware interface has a limit of 127 devices and could be reached with
a SCSI card with large disk(s) with many partitions as each partition
shows up as a separate device.

The 3.5" disk port also powers the drives and will probably run into power
problems after 6 drives.

Smartport supports two types of device - block and character. ProDOS 8
only supports block devices and will run out after 13 (slot 3, drive 2 is
reserved for /RAM on 128KB machines). P16 probably only supports block
devices. No character devices have been developed for the Smartport bus
as far as I know.
--
David Wilson  School of IT & CS, Uni of Wollongong, Australia