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From: jesup@cbmvax.commodore.com (Randell Jesup)
Newsgroups: comp.sys.amiga.programmer
Subject: Re: SCSI Direct
Message-ID: <21739@cbmvax.commodore.com>
Date: 20 May 91 06:57:29 GMT
References: <5909@mindlink.bc.ca>
Reply-To: jesup@cbmvax.commodore.com (Randell Jesup)
Organization: Commodore, West Chester, PA
Lines: 55

>*************************************************************
>*       SCSI Commands                   RESULTS
>*
>*       TEST_UNIT_READY                 $2D BadStatus
>*       REQUEST_SENSE                   $2D BadStatus
>*       INQUIRY                         $00 TEAC info REV etc
>*       READ_CAPACITY                   $2C SelTimeout
>*       MODE_SELECT                     $2D BadStatus
>*       FORMAT                          $2D BadStatus
>*       SEND DIAGNOSTIC  (Self Test)    $2C SelTimeout
>*
>*       SEND DIAGNOSTIC                 $2C SelTimeout
>*       RECEIVE DIAGNOSTIC RESULTS      GURU
>*************************************************************
>*
>    Does anybody happen to know a mapping between the result codes
> & more specific device info? ie. What do all those damn BadStatus results
> mean?

	Usually that there was some sort of error in the command.  Without
more precise info it's hard to tell.  You need to examine the full scsi
error stuff (and use SCSIF_AUTOSENSE).

>    In a .hdr file with the Xetec stuff they show their SCSI_CMD
> structure as having a few more fields than the CBM version.
> Specifically:
>*
>* Xetec extra below
>*
>scsi_SenseData          EQU     $00000016
>scsi_SenseLength        EQU     $0000001A
>scsi_SenseActual        EQU     $0000001C
>*
>*
>    Is anybody else using these? GVP? MicroBotics? Has the CBM spec grown
> or is it just Xetec?

	It was added to the file when it became a spec a long time ago.
Specify SCSIF_AUTOSENSE to the driver will automatically read the sense
data for you.

>SCSIF_WRITE             EQU     $00000000
>SCSIF_READ              EQU     $00000001

	You must specify one of these to let the driver know which way data
will be transferred.  Some drivers are smart and detect the direction from 
the phase the target goes to, but not all.

-- 
Randell Jesup, Keeper of AmigaDos, Commodore Engineering.
{uunet|rutgers}!cbmvax!jesup, jesup@cbmvax.commodore.com  BIX: rjesup  
Disclaimer: Nothing I say is anything other than my personal opinion.
Thus spake the Master Ninjei: "To program a million-line operating system
is easy, to change a man's temperament is more difficult."
(From "The Zen of Programming")  ;-)