[comp.sys.apple2] Prodos 8 & Hard Disks

shatara@islnds.enet.dec.com (Chris Shatara) (08/30/90)

I asked this a while back but have not seen any answer.

How does prodos 8 see a hard disk volume.  With GS/OS we have a SCSI 
driver/Manager to facilitate things.  What is the equivalent in P8 land?

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jsd@GAFFA.MIT.EDU (Thrill Kill Kult) (08/30/90)

In article <1888@mountn.dec.com> shatara@islnds.enet.dec.com (Chris Shatara) writes:
>How does prodos 8 see a hard disk volume.  With GS/OS we have a SCSI 
>driver/Manager to facilitate things.  What is the equivalent in P8 land?

I don't really understand this question.  Prodos 8 sees a hard drive
as a normal drive with a big volume size.  You use any normal MLI call
on it, as if it were a floppy, or a UniDisk, or a RAMdrive, or whatever...

In ProDOS, a drive is just a bunch of blocks, a hard disk even more so...

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jb10320@uxa.cso.uiuc.edu (Desdinova) (08/30/90)

In article <9008292205.AA11166@gaffa.MIT.EDU> gaffa!jsd (Jon Drukman) writes:
>In article <1888@mountn.dec.com> shatara@islnds.enet.dec.com (Chris Shatara) writes:
>>How does prodos 8 see a hard disk volume.  With GS/OS we have a SCSI 
>>driver/Manager to facilitate things.  What is the equivalent in P8 land?
>
>I don't really understand this question.  Prodos 8 sees a hard drive
>as a normal drive with a big volume size.  You use any normal MLI call
>on it, as if it were a floppy, or a UniDisk, or a RAMdrive, or whatever...

   What he is curious about is probably the drivers built-in to the ROM
on the SCSI interface card.  Every disk device that wants to work with
ProDOS must follow a specific protocol (which is described in many Apple
documents) involving having a table of addresses of functions, such as 
Read Block, Write Block, Format, etc...  GS/OS often generates a driver
for such devices unless one is specially loaded (e.g. the faster SCSI driver).

   This is a bit of a simplistic view and not totally coherent, but that's
basically it.

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