Z4648252@SFAUSTIN.BITNET (Z4648252) (05/01/89)
Recently, I mentioned a hardware device that one can plug both his
ST and hard drive into in which, during power-on bootup, the hard drive
is given power first and then, a few seconds later, the ST is given
power.
The purpose of this is to allow the hard drive to come up to speed
and other initialization. Without the delay given to the ST computer,
then the hard drive won't be recognized. Therefore, during "normal"
use, the user typically turns on his hard drive first and a few seconds
later, he then turns on his ST.
The hard drive sequencer automatically takes care of that.
There is, via some experimentation, a sortware solution.
Hang in there because none of this is legal, call-wise. Dedicate a
floppy for "startup". Place on it a text file or program. Rename this
program or text file with a .ACC extender. Test it thusly: turn off
the hard drive (to protect it temporarily--I get paranoid about this stuff). No
w give power to the ST.
Something should happen that is BAD. The renamed program or text file
should either cause a crash, or hopefully, a cold reset. If you get a cold
reset, then you are in business.
The computer should start going through a loop. It have a cold reset
and then will try to reboot. It will repeat this until you turn off the
power.
A program that does this is the SmartWatch UUECODE file listing that
appeared here a few days ago. Don't decode it. Just rename it with an
.ACC extention. Versatile listing, that. Not only do you get the clock-
on-the-chip software, if you properly decode it, but you also get a cold
reset program if you improperly rename it as I did! GRIN
Ok, here is what happens. Power the system off. For a test, you've
got to have everything plugged into a common switch box, such as a power
outlet strip. Be sure that the diskette with the cold reset accessory
which we "accidentally" created is in drive A or your internal drive.
Now place power on the strip.
You will notice that both computer and hard drive begin to work. The
hard drive will start coming up to speed. However, the ST will read the
floppy, and will then reset itself. It will reset itself three times.
On the third time, the hard drive is finally up to speed. You will now
discover that the hard drive booting up and your hard drive welcome message
appearing. Everything is now right.
From here on out, everytime you have a power failure, your system will
return on-line automatically.
Now, I don't really like this method, but it is cheap and does work. I
prefer the hardware sequencer but it involves a lot of work to build. Also
it does not require a dedicated boot-up floppy.
Also, note that the floppy cold boot-up has been tested only on the
Atari SH204 and 1987 Atari auto-start software that came with the drive. I
can't speak for the third market drives and interfaces. Indeed, some of the
interfaces may already have some sort of delay circuitry to allow for
automatic sequencing. However, since I've built so many of the sequencers
in the past two years or so, I don't think this is the case. Tech Specialties
has some sort of delay circuit for their hard drive projects but I've not
seen the circuit.
Hope this helps those who need automatic sequencing, especially those
who run BBS's.
Larry Rymal <Z4648252@SFAUSTIN.BITNET>Z4648252@SFAUSTIN.BITNET (Z4648252) (05/12/89)
Allan Pratt writes:
"Yes, we could issue the "Test Unit Ready" command to the controller, and
if there's no response, then there's no controller. If there is a
response, and it's negative, we can keep asking until it's positive.
However, there's still a timeout -- it may be that the controller is
getting power but the drive unit is not, so it'll NEVER be ready. How
long do you propose we wait?"
I can't vouch for non SH204's but I've seen power up handled perfectly
in times under eight seconds. I'd think that ten to twelve would be the
max. All the sequencers that I have built are set at ten and I've yet to
receive a complaint at that level.
A newer design which I'm prototyping is not using direct delays at all.
It merely gives power to the ST when the SH204's LED stops flashing during
powerup.
I wish I knew more about this stuff. Shucks, TOS 1.4 wouldn't have to
be changed at all. Plug the ST into the hard drive. Don't allow power to
go to the dedicated ST plug until things are 'ready'. I know this works,
primitive as it is.
My new sequencer is all but finished. I'm only trying to get costs
cheaper so that it would be better markettable. Just install a delay
on the next batch of hard drives using the aforementioned dedicated ST
plug.
Be sure to place a power switch up front for use of floppies that
require cold bootup and other bootup controls so that the drive doesn't
take control even though it isn't needed. I'm thinking about auto-booting
games, etc. Cold booting will sometimes cause the hard drive to kick in.
Sigh, all sorts of suggestions, right?
Larry Rymal <Z4648252@SFAUSTIN.BITNET>