🚀 go-pugleaf

About multiple hard disks on a single ST:

There are two basic ways to go (assuming you are starting from SH204's).

"alternative a"
If the SH204's are old enough so that you are starting from 5 1/4" drives
with separate SCSI adapters (for example the first production run of SH204's
used ST-225 drives and Adaptec 4000 SCSI adapters), you could just use the
second port on the Adaptec card.  Just get a case big enough to hold both
drives with appropriate power (for example an IBM PC clone case with a
135 watt or 150 watt power supply).  Then using your new drive (say another
ST-225) and the parts from the original SH-204 (another ST-225, Adaptec
card, Atari interface card) and the necessary cables, just mount everything
in the new box.  Both the Supra and the ICD hard disk driver software
packages will handle this configuration.

"alternative b"
The other choice is to get the necessary DB-19's and two lengths of
ten pair shielded cable.  The idea is to solder one end of both lengths
of cable to the same DB-19, and a DB-19 to each of the other ends
(a total of 3 DB-19's; use appropriate sexes of course).  All pins are
just wired through straight 1-1, 2-2, 3-3, etc.  This gives
you a y-cable.  Use the y-cable to connect both SH-204's; note that to
do this you'll need to open up the case of one and change the address
switches on the small Atari interface board.  The latest release of
the Atari hard disk driver software (the one that autoboots when the
ST is turned on without needing a floppy to boot from), or the Supra
or ICD driver packages will handle this configuration.

I've been running "alternative a" now for more than six months with
no problems (though I'm using larger drives to get a total of 170 meg
of disk space).  I know a couple of people who are using the 19 pin
Y cable approach (alternative b); once they got the cable debugged
they haven't had any problems.

dgc