Re: boot problems. scsi. 9P.

Hi,

[Jonathon Tidswell <jont@hsa.com.au> writes:]
> ----- SCSI -----

> Is anybody else considering working on scsi ?
> [ I have both IDE disk and scsi disk, tape and cdrom. ]

I am also considering working on SCSI. I just got my Adaptec 1542C up
and running last Saturday.

> My thoughts are rather abstract sofar, mostly a server that would
> create a directory tree like the following
> (/dev/??)
> scsi/
> n/
> info - things like name, [a]sync, device id, ...
> chnl - access for device <n>
> hba - this is a duplicate of the info file for whichever device id
> is used by the hba.
>
> The directory <n> would be present iff a device <n:0-7> was found on the bus.
>
> The scsi server would be written to allow only one open connection to any
> particular device chnl. [ Im not sure about FS_DUP ? ]
>
> A tape server would then attempt to search through scsi/?/info for any name
> that matched a device it knew how to handle at which point it would open
> RD.WR the chnl for that device.
>
> It may then make another directory tree available ...

What would the interface to the tape (disk, etc.) server look like? For
example, on *nix systems, you might write something like this:

        tar tvf /dev/rmt0h

> My current status is that I am looking at adaptec 1542, PC/ISA-BUS info
> and VSTa info to figure out the scsi server, I have not looked yet at the
> record structure required for messages down the device chnl.

May I suggest looking at CAM? From the SCSI FAQ:

        QUESTION: What is CAM?
        ANSWER From: ctjones@bnr.ca (Clifton Jones)
        ====
        
        Common Access Method.
        
        It is a proposed ANSI standard to make it easier to program
        SCSI applications by encapsulating the SCSI functions into a
        standardized calling convention.

In CAM, the record structure that you that you are refering to is
called a CCB (CAM Control Block).

[Andrew Valencia <vandys@cisco.com> writes:]
> If you have a copy of the technical spec for the 1542, I would really
> like to see it. I also don't have the SCSI spec for hard disks. All
> my PC technical documentation is rather old....

I called Adaptec's literature dept. yesterday. They are sending me
(free of charge) something called a "Technical Reference" manual for
the 1542. When I receive the manual, I'll let you know if it is usable
for driver writing.

                                        Mike Larson
Received on Fri Sep 10 09:38:44 1993