Re: external eSata enclosure drive recognition?

Paul wrote:
Bill in Co. wrote:

OK. When the BIOS starts, it enumerates the add-on cards. It visits them
one at a time, and reads the configuration info from the main chip.

From the "main chip" on the add-on card, I presume that means. (Not
sure
what the "main chip" is, but I guess that depends on the nature of the
card).


The chip connected to the bus present in that expansion slot. The SIL3132
chip has a PCI Express x1 interface on it, and it connects to the slot.
Probes by the BIOS, to the configuration space of the SIL3132, will
uncover it is a storage controller card. If a BIOS chip is detected,
then the next step would be to load code from the BIOS_chip.

SIL3132 ------ BIOS_chip
|
| (Enumerates via bus)
|
PCI_Express_x1_slot

If the above BIOS chip, has INT 0x13 code present, then that storage card
could contribute a drive to the boot list.

I wonder if it does (or how many actually do). Interesting.

If the card is designed like this, then a disk drive connected to the
SIL3132
cannot be used to boot the computer.

Cannot? And yet it would appear in the boot list. I don't understand
why if the system reads the BIOS on the card it's not able to boot the
computer (not that I want that, anyways). It seems you are saying above
that if the BIOS on the card is read, that it can't be used for booting?
OR that this is somehow tied into the INT 0 x 13 thing you mentioned, and
THAT is what creates that limitation?

So I'm trying to figure out exactly what *would* allow the card (and the
drive connected to it) to be bootable - just curious.

But once you get into Windows,
and install a SIL3132 driver, it is still possible for the OS to
read/write
a data hard drive.

SIL3132 ---/
|
| (Enumerates via bus, no BIOS to load)
|
PCI_Express_x1_slot


No BIOS chip is needed on the card to do that. You could unsolder the
BIOS
chip from the card, and the only consequence, is you cannot boot from
it.

OK, now here you are saying that the card BIOS *is* needed for boot
capability.

Boot from it? What kind of "cards" could you "boot from"? Maybe
you're
referring specifically to a controller card connected to a drive? And
do
you mean you could use that type of card without invoking its own BIOS
(for
that specific case) IF you didn't want to use it for a boot drive)?

You can boot from network cards, as another example of bootable devices.
A network card may have a BIOS chip, containing a PXE code module. If so,
and
there is some kind of BOOTP server on the network, then it is possible
to boot a computer via an OS stored on a server. (I'm not up on the
details of this, and have just heard of the basic mechanism.)


The BIOS will effectively ignore a PCI card, after that point.

After it has been initially enumerated - I assume that's what you mean)

Yes. Once resources are set up for a card, there is nothing else to do.


If a BIOS ROM is detected, while the BIOS is doing its probes, then the
motherboard BIOS can attempt to load the add-in BIOS.

But I would have thought that ithe system BIOS would *always* try to do
that. (Or maybe you're saying it won't do that IF it is a controller
card but is
not being used for the boot HD).

It won't do that, if the "Capture" option in the BIOS screen, has disabled
it.

What "capture option"? (I mean, I know when you go to the BIOS screen,
you can see if it has been recognized there or not, and that this was due to
the earlier enumeration, but that's all I know about that).

It also won't do it, if there is something wrong with the add-in BIOS
code. Or there isn't room to store the code in the 128KB area reserved for
such things, in low memory. If other cards have used up the 128KB area,
and
no memory is left, then the BIOS will not attempt to load the BIOS
contents
from the next add-in card. Typically, that might happen with a PC having
three SCSI cards in it. The BIOS for the third card might not load.

OK.


This card is flashed with non-RAID BIOS, and has two ESATA connectors.
$25. Install it, install the driver, then you should see a "Safely
Remove"
icon, when you connect the ESATA drive.

"Rosewill RC-219 Silicon Image PCI Express External eSATA II x2 NCQ
non-RAID"
http://www.newegg.com/Product/Product.aspx?Item=N82E16816132020

Paul

Thanks. I looked at that one, and (what appears to be) a slightly
simpler
SATA II card, using that SIL3132 chip that you mentioned. Here is the
link
for that card over at amazon.com, which seems pretty similar to the one
you
mentioned.
Its also a PCI Express to 2 External e-SATA II Ports Controller Card
(SIL3132):

http://www.amazon.com/External-e-SATA-Ports-Controller-Card/dp/B0018TE7ZG/ref=sr_1_7?ie=UTF8&s=electronics&qid=1217387126&sr=1-7

Thanks again, Paul


While I have no experience with that card on Amazon, I can say I don't
approve
of "two-headed" card designs. This is what the Amazon card is doing. It
offers four connectors,

Where are you seeing that? I'm seeing only TWO external eSata
connectors, and those are only for TWO (max) eSata drives - NOT four. Nor
are there any internal SATA connectors, from what I can tell.

but the chip only has two electrical interfaces.
And that means, they are hanging two connectors from the same bus. The
design looks like this.

SIL3132 -------------internal_connector--------external_connector
-------------internal_connector--------external_connector

You can only use one connector on each branch, at any one time. And
electrically speaking, connecting a cable and drive to the
internal_connector, leaves a stub off the high speed bus.

But again, I must be missing something, as I don't see it for that card.
(The PCI Express to 2 External e-SATA II Ports Controller Card at amazon)

The reason I picked the Rosewill card (even though I'm not a fan of
Rosewill),
is because it is set up like this.

SIL3132 -------------external_connector
-------------external_connector

That should give better electrical characteristics.

You can find other card designs, such as a card with one ESATA and
one internal SATA, if you want some flexibility. That would be like
this.

SIL3132 -------------external_connector
-------------internal_connector

Right, I thought about that, but I've already some internal eSata headers
free, so I probably don't need it, as far as I can tell. I've got four
SATA headers on the MB, and three are in use now (but one being used for the
external eSata drive right now), but maybe it's worth thinking about.


.

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