Date   : Mon, 22 Dec 1997 00:36:26 GMT
From   : Mike Mallett <mike.mallett@...>
Subject: BBC SCSI

The following which was sent to me earlier this year may be relevant :

To: Mike Mallett
Fm: BASSS5
Subject: Re: [BBC-Micro] Hard disc interfacing (FWD)
Date: 13 January 1997 23:20


Mike

Thanks for info.

You may wish to pass on the following:-

The early BBCs used a Host Adapter which conforms to the SASI standard, the 
fore runner to the SCSI standard.  The Adaptec card is to the SASI standard 
and so was the usual Disc Controller used on BBCs.  The standard is downward 
compatible, ie SCSI devices should work to SASI interfaces but not usually 
the other way round.  The Electrical signals are identical but the SCSI has 
additional commands, one of which is the Read Identity command, which is not 
implemented on SASI.  This means for instance that SASI devices are not 
always recognised on SCSI interfaces.  SCSI drives do in fact work direct to 
a BBC Host Adapter, my set-up is exactly this.

Regards

Steve

 


-- 
Mike Mallett                mike.mallett@...               Reading, UK