Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!samsung!munnari.oz.au!uhccux!waikato.ac.nz!comp.vuw.ac.nz!actrix!Roger.Sheppard
From: Roger.Sheppard@bbs.actrix.gen.nz
Newsgroups: comp.sys.atari.st.tech
Subject: Re: Some questions about how hard disks are connected to ST's
Keywords: hardware, software, hard disks, ST
Message-ID: <1991Feb13.022936.896@actrix.gen.nz>
Date: 13 Feb 91 02:29:36 GMT
References: <8448@castle.ed.ac.uk>
Sender: Roger.Sheppard@actrix.gen.nz (Roger Sheppard)
Organization: Actrix Information Exchange, Wellington, New Zealand
Lines: 33
Comment-To: john@castle.ed.ac.uk

Distribution:world 

In article <8448@castle.ed.ac.uk> john@castle.ed.ac.uk (John Hannah) writes:
> I gather that if I want to connect a hard disk to an ST(E) I need a host 
> adapter (DMA -> SCSI) (ICD etc) and a SCSI hard disk.  If I want to use 
> a ST506 disk then I need a SCSI to ST506 controller (Omti etc).  
> 
> What I want to know is :-
> 
> 1)  Where is the software for the hard disk driver ?   Is it in TOS (1.6?)
>     or a separate driver supplied by ICD etc.  If the latter - is it in PROM.
>     If not how does "autoboot" work ?

TOS does have a small routine to read the boot sector and execute it
if its set for execution. all bytes in the boot sector must add up to $1234
this can then load the hard disk driver, or any other driver for that matter.

Note; the Hard Disk driver can be loaded from Cartridge, or Floppy
The order is Cartridge, Floppy A. B ??, then Hard Disk, (Devices 0-7)

> 2)  Has anyone attached an ST506 drive without going the SCSI route ?  ie. 
>     by building their own hardware (+ software?). (I guess the answer to 
>     this question depends on question (1)!!

Yes the Germans have done that, (don't they allways)  using a PC hard disk
controller and a home made host adapter, plus patches to the TOS roms, or
a program in the Cartridge port.

> John Hannah 
> (Electrical Engineering, University of Edinburgh)



-- 
Roger W. Sheppard   85 Donovan Rd, Kapiti New Zealand...