11 Feb
2002
11 Feb
'02
5:31 a.m.
Sellam - this one is racked in a tower box as well with TEN 5 1/4"
half height drive bays - is that what you are using? I can't begin
to imagine TEN 5 1/4" FULL HEIGHT drive bays, but if that
is what you really meant, then I guess this box is only half the size.
But in addition to the 6 SCSI drives listed below, there are:
two EIDE 40 GByte hard drives - eventually to be expanded to four
one 3 1/2" floppy 1.44 MByte
one 5 1/4" floppy 1.2 MByte
one IDE CDRW burner
one IDE CDROM
Total drives = 12
the 2 (eventually 4) EIDE drives are hanging on two brackets OUTSIDE
the box - so I can see the LEDs flash on them - the LEDs are on the
bottom of the drive in the middle. The drives are hanging from secure
solid brackets at the 90 degree angle orientation so they stick out only
a total of 1 1/4" from the box - very little torque on the brackets. This
idea was from a recent suggestion about hanging drives from convenient
locations inside the box - thank you (I forget who gave the suggestion -
I simply extended it to hanging the drives outside).
I have been able to do the following with a single internal SCSI cable that
is terminated via an active external terminator (#1 configuration):
SCSI hard drive #0 FAT32 - ID=0
SCSI hard drive #1 FAT32 - ID=1
SCSI hard drive #2 FAT32 - ID=2
SCSI Iomega Zip Drive - ID=4
SCSI CDROM Drive #0 - ID=5
SCSI CDROM Drive #1 - ID=6
It all boots and work fine under W98.
I can also use an external cable as well (#2 configuration - includes #1):
Sony SMO S501 - ID=0
Sony SMO S501 - ID=1
Sony SMO S501 - ID=2 (this one only is terminated)
In this case, I MUST remove both SCSI CDROM drives from
the internal cable (not just power them down), but ONLY power
down the three SCSI hard drives. This also boots and works fine.
On many occasions, I wish to switch between the three Sony
drives and the three SCSI hard drives. Since W98 and the device
drivers think that the Sony drives are removable, none of the
software complains if I switch off (i.e. JUST turn off the power)
the Sony drives and power on the SCSI hard drives - no cables
are added or removed and I use a spare PC power supply for
SCSI hard drives, so the internal power supply for the PC is not
affected. This all works fine and since it is the minimum configuration
that I need right now, I am VERY pleased and satisfied.
Question: Can anyone suggest why I must remove the SCSI CDROM
drives from the internal SCSI cable before I can attach the external cable
with the three Sony drives - otherwise W98 does not complete the boot?
Hint: If I attempt to boot with the same configuration as #2 (i.e. with
the 3 Sony drives attached via the external cable) but now with the
3 Sony drives turned off and the 3 SCSI hard drives turned on, I also
can't boot - i.e. if I want to be able to switch between the Sony drives
and the SCSI hard drives, I must boot with the Sony drives powered
on and the SCSI hard drives powered off - and the SCSI CDROM
drives removed from the SCSI internal cable.
Please don't say I am not allowed to switch between the Sony and the
SCSI hard drives in the first place - that is something I often require -
it works and I am satisfied - if it ever stops working on future systems,
I will obviously need to find a solution.
=================================================
A note added this morning. My son#3 suggested that I eliminate the
external cable completely. Just attach a connecting cable to the end
of the internal 50 pin flat cable (remove the active terminator) to the
external Sony drives (my case will always be run with the sides off)
and put the active terminator at the end of the Sony daisy chain (instead
of having that last Sony drive apply termination - so that when I turn
off the Sony drives and power on the SCSI hard drives termination
will still be there). This all works just fine. Except that when I boot
from a floppy to be able to copy a GHOST backup file
from a CD
to the D: hard drive, I must unplug the power from the SCSI CD internal
drives as only TWO CDROM drives are recognized by the floppy
when DOS from W98 boots. Since the SCSI CD internal drives
are OT (10 years old and slow), I certainly want to use the "newer"
IDE CDROM drives which are much faster. The reason that I will
just copy the GHOST back-up file to the D: hard drive is that GHOST
will not work when I boot with CDROM support - after I do the
copy from the CD to the D: hard drive, I must boot again without
CDROM support in order to run GHOST.
All in all, the restrictions was very few. I now can now normally boot
with all four CDROM drives and the three Sony drives. Or if the
Sony drives are off, then I can boot with the three SCSI hard drives
turned on and they will be recognized as permanent had drives with
correct FAT32 file structures (I did need to do an FDISK). Of course,
in this latter case, I can't switch to the Sony drives.
The only time that I need to do something a bit unusual is to unplug
the internal power to the two SCSI CDROM drives when I boot from
a floppy and I want to copy a file from a CD to the D: drive - and then
only because of the time it takes with the old SCSI CDROM drives
as opposed to the new IDE CDROM drives.
Question: Is there agreement that the probable cause of the original
problem when there was both an external and an internal cable was
likely to do with termination? But is there a specific explanation as
to why the SCSI CDROM drives needed to be removed from the
SCSI 50 pin internal flat cable when the three Sony drives were
plugged into the external cable?
'Tis a puzzle, but now a satisfactory solution has been found.
10 Feb
10 Feb
11:44 p.m.
On Mon, 11 Feb 2002, Jerome Fine wrote:
Sellam - this one is racked in a tower box as well
with TEN 5 1/4"
half height drive bays - is that what you are using? I can't begin
to imagine TEN 5 1/4" FULL HEIGHT drive bays, but if that
is what you really meant, then I guess this box is only half the size.
No, I have 10 half-height 5.25" drive bays. 10 full height would actually
be 20 half-height, which would be insane :)
I have been able to do the following with a single
internal SCSI cable that
is terminated via an active external terminator (#1 configuration):
SCSI hard drive #0 FAT32 - ID=0
SCSI hard drive #1 FAT32 - ID=1
SCSI hard drive #2 FAT32 - ID=2
SCSI Iomega Zip Drive - ID=4
SCSI CDROM Drive #0 - ID=5
SCSI CDROM Drive #1 - ID=6
It all boots and work fine under W98.
I'm going to use SCSI Wide so I can get up to 15 devices on the chain.
Hint: If I attempt to boot with the same
configuration as #2 (i.e. with
the 3 Sony drives attached via the external cable) but now with the
3 Sony drives turned off and the 3 SCSI hard drives turned on, I also
can't boot - i.e. if I want to be able to switch between the Sony drives
and the SCSI hard drives, I must boot with the Sony drives powered
on and the SCSI hard drives powered off - and the SCSI CDROM
drives removed from the SCSI internal cable.
Probably has something to do with termination on the various combination
of devices. Even devices that are not powered up can still supply
termination as far as I know.
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
* Old computing resources for business and academia at www.VintageTech.com *
11 Feb
11 Feb
9:38 a.m.
New subject: Big box with lotsa drive bays (was: SCSI Bus Problem?
On Mon, 11 Feb 2002, Sellam Ismail wrote:
No, I have 10 half-height 5.25" drive bays. 10
full height would actually
be 20 half-height, which would be insane :)
Unless you are trying to build a dedicated disk format conversion box:
360
100 TPI (only available in full height?)
1.2 (doubles for 720K 5.25)
3
3.25
3.5 67.5 TPI (40 track)
3.5 "normal"
2.5"
2.9"
2.8M (barium ferrite disks) (can also do 1.4M)
floptical (can also do 1.4M)
syquest
zip
Jaz
Clik
Orb
CDRW
DVD
PCMCIA
and a dozen different tape drives
and external:
8"
Bernoulli
Amlyn
. . .
You might even want some software, ...
9:48 a.m.
GEtting enough SCSI devices is a problem with only 5 or 6 PCI slots. If you
use a dual or 3-channel adapter, some of the problems will go away, though.
I've not yet figured out how to make the NT box happy with the AHA3985, but it
has 3 narrow channels, to which I can hopefully attach all my old <10GB Narrow
SCSI drives. That will accomodate 21 of them. Just for cosmetic reasons, I'd
like ot have at least one old half-height SCSI drive more to fill the one
empty exposed-front bay in that box. Right now it isn't too bad with the
empty half-height (a blockout panel fits the empty space) bay.
Dick
----- Original Message -----
From: "Sellam Ismail" <foo(a)siconic.com>
To: <classiccmp(a)classiccmp.org>
Sent: Monday, February 11, 2002 3:44 AM
Subject: Re: SCSI Bus Problem?
Festival
On Mon, 11 Feb 2002, Jerome Fine wrote:
that
Sellam - this one is racked in a tower box as
well with TEN 5 1/4"
half height drive bays - is that what you are using? I can't begin
to imagine TEN 5 1/4" FULL HEIGHT drive bays, but if that
is what you really meant, then I guess this box is only half the size.
No, I have 10 half-height 5.25" drive bays. 10 full height would actually
be 20 half-height, which would be insane :)
> I have been able to do the following with a single internal SCSI cable is terminated
via an active external terminator (#1 configuration):
SCSI hard drive #0 FAT32 - ID=0
SCSI hard drive #1 FAT32 - ID=1
SCSI hard drive #2 FAT32 - ID=2
SCSI Iomega Zip Drive - ID=4
SCSI CDROM Drive #0 - ID=5
SCSI CDROM Drive #1 - ID=6
It all boots and work fine under W98.
I'm going to use SCSI Wide so I can get up to 15 devices on the chain.
Hint: If I attempt to boot with the same
configuration as #2 (i.e. with
the 3 Sony drives attached via the external cable) but now with the
3 Sony drives turned off and the 3 SCSI hard drives turned on, I also
can't boot - i.e. if I want to be able to switch between the Sony drives
and the SCSI hard drives, I must boot with the Sony drives powered
on and the SCSI hard drives powered off - and the SCSI CDROM
drives removed from the SCSI internal cable.
Probably has something to do with termination on the various combination
of devices. Even devices that are not powered up can still supply
termination as far as I know.
Sellam Ismail Vintage Computer
----------------------------------------------------------------------------
--
International Man of Intrigue and Danger
http://www.vintage.org
* Old computing resources for business and academia at www.VintageTech.com
*
9:59 a.m.
On Mon, 11 Feb 2002, Sellam Ismail wrote:
On Mon, 11 Feb 2002, Jerome Fine wrote:
Hey! I have a dual tower SCSI case (alas, missing its faceplate and drive
sleds) that has 8 full height or 16 HH openings in it. I don't think that
is too insane :P
I think the case is a clone sun enclosure, and uses 50 pin D-Sub type
connectors for the SCSI chain. Does anyone know anything about it?
Sellam - this one is racked in a tower box as
well with TEN 5 1/4"
half height drive bays - is that what you are using? I can't begin
to imagine TEN 5 1/4" FULL HEIGHT drive bays, but if that
is what you really meant, then I guess this box is only half the size.
No, I have 10 half-height 5.25" drive bays. 10 full height would
actually be 20 half-height, which would be insane :) I'm going to use SCSI Wide so I can get up to 15
devices on the chain.
Well, that only works for *wide* devices. Most all of the tape drives
you'll be needing that are SCSI will be the narrow variety. Some will be
10Mb/s (fast SCSI), but a large number of the older drives will be 5Mb/s.
-Toth
1:34 a.m.
On Mon, 11 Feb 2002, Tothwolf wrote:
Ok, I want one :)
SCSI Wide also supports plain old SCSI devices. I'm running such a
configuration in my web server (3 SCSI Wide drives and 2 SCSI-2)
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
* Old computing resources for business and academia at www.VintageTech.com *
No, I have 10
half-height 5.25" drive bays. 10 full height would
actually be 20 half-height, which would be insane :)
Hey! I have a dual tower SCSI case (alas, missing its faceplate and drive
sleds) that has 8 full height or 16 HH openings in it. I don't think that
is too insane :P I'm going
to use SCSI Wide so I can get up to 15 devices on the chain.
Well, that only works for *wide* devices. Most all of the tape drives
you'll be needing that are SCSI will be the narrow variety. Some will be
10Mb/s (fast SCSI), but a large number of the older drives will be 5Mb/s. 
11:42 a.m.
At 12:34 PM 2/11/02 +0000, you wrote:
SCSI Wide also supports plain old SCSI devices.
I'm running such a
configuration in my web server (3 SCSI Wide drives and 2 SCSI-2)
Sellam Ismail Vintage Computer Festival
Yup, sellam's right, be warned however that your SCSI bus will be hobbled
to the speed of the slowest device usually.
3:36 a.m.
On Mon, 11 Feb 2002, Geoff Reed wrote:
At 12:34 PM 2/11/02 +0000, you wrote:
Now that I didn't know. Is this only when a slower devices is being
accessed simultaneously with a faster device, or does it revert to the
lowest common denominator on the chain?
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
* Old computing resources for business and academia at www.VintageTech.com *
SCSI Wide also supports plain old SCSI devices.
I'm running such a
configuration in my web server (3 SCSI Wide drives and 2 SCSI-2)
Sellam Ismail Vintage Computer Festival
Yup, sellam's right, be warned however that your SCSI bus will be hobbled
to the speed of the slowest device usually. 
1:30 p.m.
On Mon, 11 Feb 2002, Sellam Ismail wrote:
Now that I didn't know. Is this only when a slower devices is being
accessed simultaneously with a faster device, or does it revert to the
lowest common denominator on the chain?
Ok, this is the way it works: there is a bus clock rate, and a bus width.
The bus will slow its clock rate to the clock of the slowest device, but
narrow (8-bit) and wide (16-bit) devices can coexist on a wide (16-bit)
bus. Suppose that you have two devices that run at 20MHz (ultra speed).
Even if one is ultra wide (20MHz, 16-bit) and one is plain-old ultra
(20MHz, 8-bit), the bus will be 16-bits wide. You just have to make sure
the narrow device's ID is in the lower three bits of the address space
(0-7). The wide devices can be addressed anywhere in the 4-bits of the
address space (0-f).
Peace... Sridhar
SCSI Wide also supports plain old SCSI devices.
I'm running such a
configuration in my web server (3 SCSI Wide drives and 2 SCSI-2)
Sellam Ismail Vintage Computer Festival
Yup, sellam's right, be warned however that your SCSI bus will be hobbled
to the speed of the slowest device usually.
5:22 a.m.
On Mon, 11 Feb 2002, Julius Sridhar wrote:
Ok, this is the way it works: there is a bus clock
rate, and a bus width.
The bus will slow its clock rate to the clock of the slowest device, but
narrow (8-bit) and wide (16-bit) devices can coexist on a wide (16-bit)
bus. Suppose that you have two devices that run at 20MHz (ultra speed).
Even if one is ultra wide (20MHz, 16-bit) and one is plain-old ultra
(20MHz, 8-bit), the bus will be 16-bits wide. You just have to make sure
the narrow device's ID is in the lower three bits of the address space
(0-7). The wide devices can be addressed anywhere in the 4-bits of the
address space (0-f).
Thanks. That clears things up.
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
* Old computing resources for business and academia at www.VintageTech.com *
12:05 p.m.
On Mon, 11 Feb 2002, Geoff Reed wrote:
At 12:34 PM 2/11/02 +0000, you wrote:
Right. I'd certainly not mix wide and narrow devices on one channel.
Termination of the bus is also often a pain when you do this.
What can't be done, is put 15 narrow devices on one wide channel. Well, at
least and have them all work anyway.
-Toth
SCSI Wide also supports plain old SCSI devices.
I'm running such a
configuration in my web server (3 SCSI Wide drives and 2 SCSI-2)
Yup, sellam's right, be warned however that your SCSI bus will be hobbled
to the speed of the slowest device usually.
3:46 a.m.
On Mon, 11 Feb 2002, Tothwolf wrote:
On Mon, 11 Feb 2002, Geoff Reed wrote:
It wasn't much of a problem for me. I'm using an Adaptec 2940UW (or is it
a 2940W?) and it has both SCSI and SCSI Wide connectors on the card
internally, and a connector on the back that may or may not be SCSI Wide.
I think either you specify in the card's BIOS setup whether you want
to use the internal connectors or a combination of one of the internal
connectors and the external connector, or it auto-detects (I haven't
played with it in a long time, but I know at one point I had a Syquest EZ
Flyer attached to the external connector along with the internal SCSI Wide
drives). If you attach drives to all three, you get problems (I know this
At 12:34 PM 2/11/02 +0000, you wrote:
Right. I'd certainly not mix wide and narrow devices on one channel.
Termination of the bus is also often a pain when you do this. SCSI Wide also supports plain old SCSI devices.
I'm running such a
configuration in my web server (3 SCSI Wide drives and 2 SCSI-2)
Yup, sellam's right, be warned however that your SCSI bus will be hobbled
to the speed of the slowest device usually. from experience ;)
So you just terminate each device at the end of whatever chains you use.
If you use the internal SCSI and SCSI Wide chains, you terminate the last
SCSI device and the last SCSI Wide device. If you use the external
connector, apply termination to the last device on the external chain and
the last device on the internal chain. It works perfectly.
What can't be done, is put 15 narrow devices on
one wide channel. Well,
at least and have them all work anyway.
Narrow devices are only able to address up to SCSI ID 7 as far as I know
(otherwise they'd be SCSI Wide devices). Only Wide devices know that
devices IDs from 8-15 exist.
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
* Old computing resources for business and academia at www.VintageTech.com *
1:43 p.m.
On Mon, 11 Feb 2002, Sellam Ismail wrote:
Right. I'd certainly not mix wide and narrow devices on one channel.
Termination of the bus is also often a pain when you do this.
It wasn't much of a problem for me. I'm using an Adaptec 2940UW (or is it
a 2940W?) and it has both SCSI and SCSI Wide connectors on the card
internally, and a connector on the back that may or may not be SCSI Wide.
I think either you specify in the card's BIOS setup whether you want
to use the internal connectors or a combination of one of the internal
connectors and the external connector, or it auto-detects (I haven't
played with it in a long time, but I know at one point I had a Syquest EZ
Flyer attached to the external connector along with the internal SCSI Wide
drives). If you attach drives to all three, you get problems (I know this
from experience ;)
That's because that's one big bus. If you're using the internal 50- and
68-pin connectors, the high 8 bits are terminated on the card. Same if
you're using the external 68-pin and the internal 50-pin. If you're using
the internal *and* external 68-pin, termination is disabled on the card.
You can't have a SCSI-star, it has to be a bus, so therefore only two
connectors can be used at a time.
SCSI Wide also
supports plain old SCSI devices. I'm running such a
configuration in my web server (3 SCSI Wide drives and 2 SCSI-2)
Yup, sellam's right, be warned however that your SCSI bus will be hobbled
to the speed of the slowest device usually. So you just terminate each device at the end of
whatever chains you use.
If you use the internal SCSI and SCSI Wide chains, you terminate the last
SCSI device and the last SCSI Wide device. If you use the external
connector, apply termination to the last device on the external chain and
the last device on the internal chain. It works perfectly.
In wide SCSI, there is high-byte and low-byte termination. Suppose you
have the following on your wide SCSI bus:
(Host ID 7) -> (Wide ID A) -> (Wide ID 9) -> (Narrow ID 0)
Then both bytes have to be terminated on the host, the high byte needs to
be terminated on ID 9, and the low byte on 0 (it's the only termination
device 0 knows how to do, so you just have to tell it to terminate.)
Now if you add another device at the end of the chain so that it's now:
(Host ID 7) -> (Wide ID A) -> (Wide ID 9) -> (Narrow ID 0) -> (Wide ID 1)
Then you wouldn't terminate device 0, but you would terminate the low byte
of 1, and device 1 will run in narrow mode, because 9 has already
terminated the high byte. Also, you can't have an ID > 7 on device 1.
Peace... Sridhar
What can't
be done, is put 15 narrow devices on one wide channel. Well,
at least and have them all work anyway.
Narrow devices are only able to address up to SCSI ID 7 as far as I know
(otherwise they'd be SCSI Wide devices). Only Wide devices know that
devices IDs from 8-15 exist.
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
* Old computing resources for business and academia at www.VintageTech.com *
12:25 p.m.
On Mon, 11 Feb 2002, Tothwolf wrote:
Right. I'd certainly not mix wide and narrow devices on one channel.
Termination of the bus is also often a pain when you do this.
A narrow device will not slow down a wide bus to narrow width. But a
10 MHz device will slow down a 20 MHz SCSI bus to 10MHz.
SCSI Wide also supports plain old SCSI devices.
I'm running such a
configuration in my web server (3 SCSI Wide drives and 2 SCSI-2)
Yup, sellam's right, be warned however that your SCSI bus will be hobbled
to the speed of the slowest device usually. What can't be done, is put 15 narrow devices on
one wide channel. Well, at
least and have them all work anyway.
Agreed.
Peace... Sridhar
3:49 a.m.
On Mon, 11 Feb 2002, Julius Sridhar wrote:
A narrow device will not slow down a wide bus to
narrow width. But a
10 MHz device will slow down a 20 MHz SCSI bus to 10MHz.
You're contradicting yourself here. Either that or the semantics of your
sentence are confusing :)
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
* Old computing resources for business and academia at www.VintageTech.com *
1:16 p.m.
On Mon, 11 Feb 2002, Julius Sridhar wrote:
Both the 20Mhz (Ultra) and 10 Mhz SCSI buses are narrow.
Standard SCSI runs at 5 Mhz, Fast-SCSI at 10 Mhz, Ultra at 20Mhz and
Ultra2/Wide is 40Mhz. The various versions of Wide go up to 160Mhz
and 30 devices now. 20Mhz and below is still narrow width, just
different speeds. The bus will slow itself to the speed of the
slowest item on the bus. To put a narrow item on a wide bus requires
some sort of adapter so the narrow item only changes the speed of the
bus, not the data width of the whole bus.
Jeff
--
Home of the TRS-80 Model 2000 FAQ File
http://www.cchaven.com
http://www.geocities.com/siliconvalley/lakes/6757
A narrow device will not slow down a wide bus to
narrow width. But a
10 MHz device will slow down a 20 MHz SCSI bus to 10MHz.
You're contradicting yourself here. Either that or the semantics of your
sentence are confusing :)
1:53 p.m.
On Mon, 11 Feb 2002, Jeff Hellige wrote:
What are you talking about? There are 20MHz (and even 10MHz) wide
devices.
Peace... Sridhar
>You're
contradicting yourself here. Either that or the semantics
of your >sentence are
confusing :)
Both the 20Mhz (Ultra) and 10 Mhz SCSI buses are narrow.
Standard SCSI runs at 5 Mhz, Fast-SCSI at 10 Mhz, Ultra at 20Mhz and
Ultra2/Wide is 40Mhz. The various versions of Wide go up to 160Mhz
and 30 devices now. 20Mhz and below is still narrow width, just
different speeds. The bus will slow itself to the speed of the
slowest item on the bus. To put a narrow item on a wide bus requires
some sort of adapter so the narrow item only changes the speed of the
bus, not the data width of the whole bus.
3:14 p.m.
ISTR that the ADAPTEC BIOS setup allows maximal rates to be set in advance, so
you don't waste a lot of time trying to run a slow device fast. Nevertheless,
it's at least possible, if not always practicable, to operate the SCSI at
rates compatible with the fastest the devices can handle. This, I believe, is
intended to alleviate accomodating slow devices at the expense of fast ones.
I don't think it was ever the committee's intention to slow the entire bus
down to that of the slowest device, though they did make provision for
different rates based on the signalling protocol. The controller has to
"know" the limits for synchronous transfer, however.
Dick
----- Original Message -----
From: "Jeff Hellige" <jhellige(a)earthlink.net>
To: <classiccmp(a)classiccmp.org>
Sent: Monday, February 11, 2002 5:16 PM
Subject: Re: SCSI Bus Problem?
On Mon, 11 Feb
2002, Julius Sridhar wrote:
Both the 20Mhz (Ultra) and 10 Mhz SCSI buses are narrow.
Standard SCSI runs at 5 Mhz, Fast-SCSI at 10 Mhz, Ultra at 20Mhz and
Ultra2/Wide is 40Mhz. The various versions of Wide go up to 160Mhz
and 30 devices now. 20Mhz and below is still narrow width, just
different speeds. The bus will slow itself to the speed of the
slowest item on the bus. To put a narrow item on a wide bus requires
some sort of adapter so the narrow item only changes the speed of the
bus, not the data width of the whole bus.
Jeff
--
Home of the TRS-80 Model 2000 FAQ File
http://www.cchaven.com
http://www.geocities.com/siliconvalley/lakes/6757
A narrow device will not slow down a wide bus to
narrow width. But a
10 MHz device will slow down a 20 MHz SCSI bus to 10MHz.
You're contradicting yourself here. Either that or the semantics of your
sentence are confusing :)
1:23 p.m.
On Mon, 11 Feb 2002, Sellam Ismail wrote:
On Mon, 11 Feb 2002, Julius Sridhar wrote:
SCSI itself is confusing...basically the bus will operate at the fastest
rate of the slowest device on the bus.
Original - narrow, 5Mb/s [used by lots of older devices]
Fast - narrow 10Mb/s [very common]
Ultra - narrow 20Mb/s [very common]
Wide - wide, 20Mb/s [common for a short time]
Ultra-Wide - wide, 40Mb/s [very common]
Ultra2 - wide, 80Mb/s [never really caught on]
Ultra160 - wide, 160Mb/s [starting to become common]
Ultra320 - wide, 320Mb/s [not common yet]
(info from memory, might be incomplete, inaccurate, etc, etc)
There are also Differential versions of Fast, Ultra, Wide, and Ultra-Wide.
These use a "high voltage" (+-12VDC IIRC) signaling that is *NOT*
compatible with standard devices. You will literally fry any non HVD
devices if you connect a HVD drive to the same bus. Ultra2 and newer have
a Low Voltage Differential bus, I'm not sure if there is a HVD
specification for those.
-Toth
A narrow device will not slow down a wide bus to
narrow width. But a
10 MHz device will slow down a 20 MHz SCSI bus to 10MHz.
You're contradicting yourself here. Either that or the semantics of
your sentence are confusing :)
1:52 p.m.
On Mon, 11 Feb 2002, Tothwolf wrote:
SCSI itself is confusing...basically the bus will operate at the fastest
rate of the slowest device on the bus.
This is simply not the case.
A narrow device will not slow down a wide bus to
narrow width. But a
10 MHz device will slow down a 20 MHz SCSI bus to 10MHz.
You're contradicting yourself here. Either that or the semantics of
your sentence are confusing :) Original - narrow, 5Mb/s [used by lots of older
devices]
Fast - narrow 10Mb/s [very common]
Ultra - narrow 20Mb/s [very common]
Wide - wide, 20Mb/s [common for a short time]
Ultra-Wide - wide, 40Mb/s [very common]
Ultra2 - wide, 80Mb/s [never really caught on]
Ultra160 - wide, 160Mb/s [starting to become common]
Ultra320 - wide, 320Mb/s [not common yet]
Ok. First of all, it's MB/s, rather than Mb/s. Second, MB/s is not a
good way to describe the bandwidth of the bus for technical reasons. A
fast/wide 20MB/s bus looks *nothing* like an ultra 20MB/s bus. This is so
because fast/wide is a 10MHz 16-bit bus and ultra is a 20MHz 8-bit bus.
Just because they have the same bandwidth doesn't mean anything. An ultra
device will run at 10MB/s on a fast/wide bus and a fast/wide device will
run at 10MB/s on an ultra bus. Both busses are *capable* of 20MB/s. If
you have an ultra device and an ultra/wide device on an ultra/wide bus,
the ultra device will run at 20MB/s and the ultra/wide device will run at
40MB/s *simultaneously* **on the same bus**.
(info from memory, might be incomplete, inaccurate,
etc, etc)
There are also Differential versions of Fast, Ultra, Wide, and Ultra-Wide.
These use a "high voltage" (+-12VDC IIRC) signaling that is *NOT*
compatible with standard devices. You will literally fry any non HVD
devices if you connect a HVD drive to the same bus. Ultra2 and newer have
a Low Voltage Differential bus, I'm not sure if there is a HVD
specification for those.
Signalling voltages are irrelevant to this discussion.
Peace... Sridhar
5:46 p.m.
On Mon, 11 Feb 2002, Julius Sridhar wrote:
Actually, I think not. With the way this thread has been going, I think it
is quite a good idea to mention the differences between "standard", HVD,
and LVD signaling.
-Toth
On Mon, 11 Feb 2002, Tothwolf wrote:
*shrug*
Actually, it would have been better to type the whole thing up with 'MHz'
and bus width, instead of just MB/s, but I was in a hurry. Oh well, use
Google.
Original - narrow, 5Mb/s [used by lots of
older devices]
Fast - narrow 10Mb/s [very common]
Ultra - narrow 20Mb/s [very common]
Wide - wide, 20Mb/s [common for a short time]
Ultra-Wide - wide, 40Mb/s [very common]
Ultra2 - wide, 80Mb/s [never really caught on]
Ultra160 - wide, 160Mb/s [starting to become common]
Ultra320 - wide, 320Mb/s [not common yet]
Ok. First of all, it's MB/s, rather than Mb/s. Second, MB/s is not a good way to describe the
bandwidth of the bus
for technical reasons. A fast/wide 20MB/s bus looks *nothing* like an
ultra 20MB/s bus. This is so because fast/wide is a 10MHz 16-bit bus
and ultra is a 20MHz 8-bit bus.
I didn't imply that a "fast-wide" bus was anything like the
"ultra" bus.
Just because they have the same bandwidth doesn't
mean anything. An
ultra device will run at 10MB/s on a fast/wide bus and a fast/wide
device will run at 10MB/s on an ultra bus. Both busses are *capable*
of 20MB/s.
Of course the ultra device would run at 10MB/s, a fast/wide bus runs at
10MHz, and the ultra device is only 8 bit instead of 16.
If you have an ultra device and an ultra/wide device
on an ultra/wide
bus, the ultra device will run at 20MB/s and the ultra/wide device
will run at 40MB/s *simultaneously* **on the same bus**.
I'm not disputing that.
> (info from memory, might be incomplete,
inaccurate, etc, etc)
Uhm, I did put a disclaimer in here...
There are also
Differential versions of Fast, Ultra, Wide, and Ultra-Wide.
These use a "high voltage" (+-12VDC IIRC) signaling that is *NOT*
compatible with standard devices. You will literally fry any non HVD
devices if you connect a HVD drive to the same bus. Ultra2 and newer have
a Low Voltage Differential bus, I'm not sure if there is a HVD
specification for those.
Signalling voltages are irrelevant to this discussion. 
12 Feb
12 Feb
6:05 a.m.
Tothwolf wrote:
On Mon, 11 Feb 2002, Julius Sridhar wrote:
Actually, I think not. With the way this thread has been going, I think it
is quite a good idea to mention the differences between "standard", HVD,
and LVD signaling.
-Toth
Then AFAIK, you can put an Ultra 160 LBD drive on an UW card, and it
will revert to single ended UW operation. HV differential is a world
unto itself.
Gary Hildebrand
ST. Joseph, MO
On Mon, 11 Feb 2002, Tothwolf wrote:
*shrug*
Actually, it would have been better to type the whole thing up with 'MHz'
and bus width, instead of just MB/s, but I was in a hurry. Oh well, use
Google.
Original - narrow, 5Mb/s [used by lots of
older devices]
Fast - narrow 10Mb/s [very common]
Ultra - narrow 20Mb/s [very common]
Wide - wide, 20Mb/s [common for a short time]
Ultra-Wide - wide, 40Mb/s [very common]
Ultra2 - wide, 80Mb/s [never really caught on]
Ultra160 - wide, 160Mb/s [starting to become common]
Ultra320 - wide, 320Mb/s [not common yet]
Ok. First of all, it's MB/s, rather than Mb/s. Second, MB/s is not a good way to describe the
bandwidth of the bus
for technical reasons. A fast/wide 20MB/s bus looks *nothing* like an
ultra 20MB/s bus. This is so because fast/wide is a 10MHz 16-bit bus
and ultra is a 20MHz 8-bit bus.
I didn't imply that a "fast-wide" bus was anything like the
"ultra" bus.
Just because they have the same bandwidth
doesn't mean anything. An
ultra device will run at 10MB/s on a fast/wide bus and a fast/wide
device will run at 10MB/s on an ultra bus. Both busses are *capable*
of 20MB/s.
Of course the ultra device would run at 10MB/s, a fast/wide bus runs at
10MHz, and the ultra device is only 8 bit instead of 16.
If you have an ultra device and an ultra/wide
device on an ultra/wide
bus, the ultra device will run at 20MB/s and the ultra/wide device
will run at 40MB/s *simultaneously* **on the same bus**.
I'm not disputing that.
> (info from memory, might be incomplete,
inaccurate, etc, etc)
Uhm, I did put a disclaimer in here...
There are
also Differential versions of Fast, Ultra, Wide, and Ultra-Wide.
These use a "high voltage" (+-12VDC IIRC) signaling that is *NOT*
compatible with standard devices. You will literally fry any non HVD
devices if you connect a HVD drive to the same bus. Ultra2 and newer have
a Low Voltage Differential bus, I'm not sure if there is a HVD
specification for those.
Signalling voltages are irrelevant to this discussion.
5:55 a.m.
I can verify that, in that it's exactly what I've recently done. True, also,
that "HV" differential signalling, which was devised mainly to enhance cabling
options (by allowing for much longer cables) in small disk farms before
FiberChannel became a ubiquitous option, is in no way compatible with the
older 5-volt single-ended SCSI, whether wide or narrow.
There's a signal referred to as DIFFSENS that detects whether the interface is
LVD or SE, but it is only present on the more recent SCA types. My FUJITSU
SCA-2 drives, among others, detect this signal and automatically figure out
whether to use single-ended or LVD signalling. It also figures out whether
it's wide or narrow, with a little help from the controller, and is quite
capable of operating in either wide or narrow mode. Drives of the current
generation are capable of data widths up to 64 bits, which width none of my
drives/controllers can process, but the cable capacity is the rate-determining
step in this environment, and if your cables and controller can process SCSI
bus transactions at 20 MHz, then you can transfer the entire word width,
whatever it is in your case, at that rate. Normally, the bus width for older
devices is either 8 or 16 bits.
Where folks get into trouble is when they mix devices with different
synchronous speed capabilities. If they do so without setting the parameters
in the controller to match, then the device selection process can break down
and the entire bus then has to be slowed down to the "lowest common
denominator," so to speak, in order to allow business to be transacted
"normally."
Dick
----- Original Message -----
From: "Gary Hildebrand" <ghldbrd(a)ccp.com>
To: <classiccmp(a)classiccmp.org>
Sent: Tuesday, February 12, 2002 10:05 AM
Subject: Re: SCSI Bus Problem?
<snip>
Then AFAIK, you can put an Ultra 160 LVD drive on an
UW card, and it
will revert to single ended UW operation. HV differential is a world
unto itself.
Gary Hildebrand
ST. Joseph, MO
11 Feb
11 Feb
2:06 p.m.
Well, damn, I didn't know that. I thought the controller change speeds to
talk to the device that was being addressed. It makes little sense that the
slowest device should slow down the whole bus to it's speed.
--John
-----Original Message-----
From: owner-classiccmp(a)classiccmp.org
[mailto:owner-classiccmp@classiccmp.org]On Behalf Of Tothwolf
Sent: Monday, February 11, 2002 19:23 PM
To: classiccmp(a)classiccmp.org
Subject: Re: SCSI Bus Problem?
On Mon, 11 Feb 2002, Sellam Ismail wrote:
On Mon, 11 Feb 2002, Julius Sridhar wrote:
SCSI itself is confusing...basically the bus will operate at the fastest
rate of the slowest device on the bus.
Original - narrow, 5Mb/s [used by lots of older devices]
Fast - narrow 10Mb/s [very common]
Ultra - narrow 20Mb/s [very common]
Wide - wide, 20Mb/s [common for a short time]
Ultra-Wide - wide, 40Mb/s [very common]
Ultra2 - wide, 80Mb/s [never really caught on]
Ultra160 - wide, 160Mb/s [starting to become common]
Ultra320 - wide, 320Mb/s [not common yet]
(info from memory, might be incomplete, inaccurate, etc, etc)
There are also Differential versions of Fast, Ultra, Wide, and
Ultra-Wide.
These use a "high voltage" (+-12VDC IIRC) signaling that is *NOT*
compatible with standard devices. You will literally fry any non HVD
devices if you connect a HVD drive to the same bus. Ultra2 and newer have
a Low Voltage Differential bus, I'm not sure if there is a HVD
specification for those.
-Toth
A narrow device will not slow down a wide bus to
narrow width. But a
10 MHz device will slow down a 20 MHz SCSI bus to 10MHz.
You're contradicting yourself here. Either that or the semantics of
your sentence are confusing :)
1:44 p.m.
On Mon, 11 Feb 2002, Sellam Ismail wrote:
I *did not* give my units in MBps. I gave them in *MHz*.
Peace... Sridhar
A narrow device will not slow down a wide bus to
narrow width. But a
10 MHz device will slow down a 20 MHz SCSI bus to 10MHz.
You're contradicting yourself here. Either that or the semantics of your
sentence are confusing :)
12:54 p.m.
A narrow device will not slow down a wide bus to narrow
width. But a
10 MHz device will slow down a 20 MHz SCSI bus to 10MHz.
Definately don't want to plug a 5mhz SCSI-1 drive up to a
40mhz Ultra2 SCSI, or better, board if you have other drives running
at the boards full speed! I have had to go the other direction
though to get a large 68pin Wide drive installed on a 10mhz SCSI bus
in an older machine. In that case, the capacity it added was much
more important than the lost speed of the drive.
Jeff
--
Home of the TRS-80 Model 2000 FAQ File
http://www.cchaven.com
http://www.geocities.com/siliconvalley/lakes/6757
12:38 p.m.
Do the old narrow devices even support the ID's over 7? I didn't think that
cam eout until wide devices.
=> -----Original Message-----
=> From: owner-classiccmp(a)classiccmp.org
=> [mailto:owner-classiccmp@classiccmp.org]On Behalf Of Tothwolf
=> Sent: Monday, February 11, 2002 5:06 PM
=> To: classiccmp(a)classiccmp.org
=> Subject: Re: SCSI Bus Problem?
=>
=>
=> On Mon, 11 Feb 2002, Geoff Reed wrote:
=> > At 12:34 PM 2/11/02 +0000, you wrote:
=> >
=> > >SCSI Wide also supports plain old SCSI devices. I'm running such a
=> > >configuration in my web server (3 SCSI Wide drives and 2 SCSI-2)
=> >
=> > Yup, sellam's right, be warned however that your SCSI bus will
=> be hobbled
=> > to the speed of the slowest device usually.
=>
=> Right. I'd certainly not mix wide and narrow devices on one channel.
=> Termination of the bus is also often a pain when you do this.
=>
=> What can't be done, is put 15 narrow devices on one wide
=> channel. Well, at
=> least and have them all work anyway.
=>
=> -Toth
=>
12:18 p.m.
SCSI Wide also
supports plain old SCSI devices. I'm running such a
configuration in my web server (3 SCSI Wide drives and 2 SCSI-2)
Sellam Ismail Vintage
Computer Festival
Yup, sellam's right, be warned however that your SCSI bus will be
hobbled to the speed of the slowest device usually.
1:26 p.m.
On Mon, 11 Feb 2002, Jeff Hellige wrote:
Which is why I keep two seperate SCSI cards running in my
main Mac...a Wide board for the internal SCSI hard disks and an
Ultra/Narrow for anything external I might wish to plug up to it,
such as CD-R and scanner.
A narrow device will not reduce a wide bus to a narrow one.
Peace... Sridhar
SCSI Wide also supports plain old SCSI devices.
I'm running such a
configuration in my web server (3 SCSI Wide drives and 2 SCSI-2)
Sellam Ismail Vintage
Computer Festival
Yup, sellam's right, be warned however that your SCSI bus will be
hobbled to the speed of the slowest device usually.
3:07 p.m.
That doesn't have to be the case if you are careful about your cabling and
termination. I've got narrow (50-contacts), wide (68 contacts), and
"ultra-wide" (SCA-80) devices all on the same cable with the appropriate
adapters. The performance of each device doesn't seem to be much different
from the same device on a cable with only that
"width" on it. Multiple
devices being tested (via the ADAPTEC
SCSIBENCH.EXE program) seem to operate a
mite slower than the same devic alone.
If you fail to terminate the upper data bits, fail to set the jumpers
correctly, or fail to sequence the devices correctly on the cable, performance
will ordinarily be compromised. My FUJITSU SCA drives respond to the data
jumper on its control board, but performs quite admirably as an 8-bit device
when given an 8-bit transfer configuration via software even though cabled and
terminated for 16-bit operation.
YMMV, I suppose.
Dick
----- Original Message -----
From: "Geoff Reed" <geoffr(a)zipcon.net>
To: <classiccmp(a)classiccmp.org>
Sent: Monday, February 11, 2002 3:42 PM
Subject: Re: SCSI Bus Problem?
At 12:34 PM 2/11/02 +0000, you wrote:
>SCSI Wide also supports plain old SCSI devices. I'm running such a
>configuration in my web server (3 SCSI Wide drives and 2 SCSI-2)
>
>Sellam Ismail Vintage Computer
Festival
Yup, sellam's right, be warned however that your SCSI bus will be hobbled
to the speed of the slowest device usually.
3:31 p.m.
On Mon, 11 Feb 2002, Geoff Reed wrote:
At 12:34 PM 2/11/02 +0000, you wrote:
And that common wisdom, performance-wise, is to use only 1/3 of your
available IDs for active devices. ie. on a wide bus, performance drops
like a rock with more than 5 devices on the chain. Not that this looks
like a high-speed rig to start with.
Actually, IIRC, a wide bus will be hobbled to SCSI-2, 20Mbit max, but
fater drives will usually run at 20Mb. SCSI-2 allows mixed negotiated
speeds. Put the slowest device at the highest ID.
Doc
SCSI Wide also supports plain old SCSI devices.
I'm running such a
configuration in my web server (3 SCSI Wide drives and 2 SCSI-2)
Sellam Ismail Vintage Computer Festival
Yup, sellam's right, be warned however that your SCSI bus will be hobbled
to the speed of the slowest device usually. 
11:24 a.m.
On Mon, 11 Feb 2002, Jerome Fine wrote:
Where are you two finding cases with 10 half-height 5.25" drive bays?!?! I
had a nightmarish time a little over a year ago finding one with just 6
bays! The other question is, how tall are these cases? My 6 bay one barely
fits under the desk.
Zane
Sellam - this one is racked in a tower box as
well with TEN 5 1/4"
half height drive bays - is that what you are using? I can't begin
No, I have 10 half-height 5.25" drive bays. 10 full height would actually
be 20 half-height, which would be insane :)
3:33 a.m.
On Mon, 11 Feb 2002, Zane H. Healy wrote:
I've had this for over ten years. Even back then it was a monster. I
bought it with the intent of building my first PC but making it a
mega-doozy. I paid $85 for it and never used it.
It is odd in that the back of the motherboard is at the top of the box. A
lid on the top comes off exposing the cables and connectors, which are
drawn out the back of the case through a cable-way that the lid creates.
3-4 bays are exposed through the front. To expose the other 6-7 bays you
open the front door which exposes access to all the bays.
It has enough room inside for a full-sized motherboard and a big-assed
power supply, plus enough space left over to mount some hard drives.
It was made by Arche (?). It's all metal and is powder coated. It sits
about 32" high.
I also have a big tower case that is just an overgrown version of a
regular tower. It has 5 bays. I think I'll use that as my SCSI box.
There's a 6-bay tower in a pile at the ACCRC that I may claim. If I
don't, and someone wants it, it can be had for a nominal donation to the
ACCRC plus shipping.
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
* Old computing resources for business and academia at www.VintageTech.com *
No, I have 10
half-height 5.25" drive bays. 10 full height would actually
be 20 half-height, which would be insane :)
Where are you two finding cases with 10 half-height 5.25" drive bays?!?! I
had a nightmarish time a little over a year ago finding one with just 6
bays! The other question is, how tall are these cases? My 6 bay one barely
fits under the desk.
1:46 p.m.
I have one that was a cdrom tower, now houses 4x FH 5.25" HDD's - it's due
to get stripped and sold off soon but not cheap as it's barely 3 yrs old and
most of that time it was in it's shipping carton.
=> -----Original Message-----
=> From: owner-classiccmp(a)classiccmp.org
=> [mailto:owner-classiccmp@classiccmp.org]On Behalf Of Sellam Ismail
=> Sent: Monday, February 11, 2002 8:34 AM
=> To: classiccmp(a)classiccmp.org
=> Subject: Re: SCSI Bus Problem?
=>
=>
=> On Mon, 11 Feb 2002, Zane H. Healy wrote:
=>
=> > > No, I have 10 half-height 5.25" drive bays. 10 full height
=> would actually
=> > > be 20 half-height, which would be insane :)
=> >
=> > Where are you two finding cases with 10 half-height 5.25"
=> drive bays?!?! I
=> > had a nightmarish time a little over a year ago finding one with just 6
=> > bays! The other question is, how tall are these cases? My 6
=> bay one barely
=> > fits under the desk.
=>
=> I've had this for over ten years. Even back then it was a monster. I
=> bought it with the intent of building my first PC but making it a
=> mega-doozy. I paid $85 for it and never used it.
=>
=> It is odd in that the back of the motherboard is at the top of the box. A
=> lid on the top comes off exposing the cables and connectors, which are
=> drawn out the back of the case through a cable-way that the lid creates.
=> 3-4 bays are exposed through the front. To expose the other 6-7 bays you
=> open the front door which exposes access to all the bays.
=>
=> It has enough room inside for a full-sized motherboard and a big-assed
=> power supply, plus enough space left over to mount some hard drives.
=>
=> It was made by Arche (?). It's all metal and is powder coated. It sits
=> about 32" high.
=>
=> I also have a big tower case that is just an overgrown version of a
=> regular tower. It has 5 bays. I think I'll use that as my SCSI box.
=>
=> There's a 6-bay tower in a pile at the ACCRC that I may claim. If I
=> don't, and someone wants it, it can be had for a nominal donation to the
=> ACCRC plus shipping.
=>
=> Sellam Ismail Vintage
=> Computer Festival
=> -----------------------------------------------------------------
=> -------------
=> International Man of Intrigue and Danger
http://www.vintage.org
* Old computing resources for business and academia at www.VintageTech.com
*
2:25 p.m.
=> > Where are you two finding cases with 10
half-height 5.25"
=> drive bays?!?! I
http://www.calpc.com/html/super_server.html, last I checked, they were under
500$,
Zach
12:09 p.m.
On Mon, 11 Feb 2002, Zane H. Healy wrote:
I bought one with 10 bays back in '97-98 from a local dealer for $120 or
so. I still use it for my workstation machine. Including the height added
by the casters, mine is 29 inches high. Cases this size don't really fit
well under most desks.
-Toth
No, I have 10 half-height 5.25" drive bays.
10 full height would actually
be 20 half-height, which would be insane :)
Where are you two finding cases with 10 half-height 5.25" drive
bays?!?! I had a nightmarish time a little over a year ago finding
one with just 6 bays! The other question is, how tall are these
cases? My 6 bay one barely fits under the desk.
1:37 p.m.
New subject: Big PC boxes (was: SCSI Bus Problem?
On Mon, 11 Feb 2002, Tothwolf wrote:
I bought one with 10 bays back in '97-98 from a
local dealer for $120 or
so. I still use it for my workstation machine. Including the height added
by the casters, mine is 29 inches high. Cases this size don't really fit
^^^^^^^
When you get up to a dozen or so drive bays, does it start becoming a REAL
computer?
2:31 p.m.
New subject: Big PC boxes (was: SCSI Bus Problem?
It does get to the point that it gets REAL expensive, REAL hot and REAL
noisy though. My Netserver LX Pro presently has 12 hotswap bays with 6
filled with 9.1 gb drives, 3 more on the way and keeping an eye peeled for 3
more. It also has 2 4.3 gb drives in the 2 right side fixed bays in 5.25" to
3.5" HDD trays for the OS to reside on (Raid 0 on those but tape backup
daily). The drives are quiet as can be, ST19171WC's but the heat and noise
of 4x Pentium Pros, 3 power supplies, bunches of fans and all those drives
in a small server room made a need for a door to quiet it down and a vent
fan to the outside of the room (keeps the rest of the basement shop comfy
too without the furnace kicking in). I was going to insulate the room for
noise but heat was a bigger issue and I want to let it out, not hold it in.
My older IBM PC Server 320 is coming apart soon as I xfer the old data and
all my old 5.25" 50 and 68 pin drives go up on ebay, as does the tower and
cdroms. I'm keeping my Microtest 14 cdrom tower but since it doesn't work
under Windows 2000 server I'm diabling the SCSI to 10baseT card and putting
the flat ribbons onto 2 external connectors (1 per 7 drives of course) and
cabling them direct to an Adaptec PCI F/W adapter. I was going to use my
older EISA adapter but the speed just wasn't there for the 12x cdrom
drives - plus I can swap one of the 12x drives to a CDRW drive if I need,
something that didn't work on the SCSI-to-10baseT card under NT4 server.
=> -----Original Message-----
=> When you get up to a dozen or so drive bays, does it start
=> becoming a REAL
=> computer?
5:50 p.m.
New subject: Big PC boxes (was: SCSI Bus Problem?
On Mon, 11 Feb 2002, Fred Cisin (XenoSoft) wrote:
On Mon, 11 Feb 2002, Tothwolf wrote:
Well, when the "other" computer is a SGI/Sun/VAX/NeXT/whatever, I think
it's close enough ;)
I certainly make use of the extra bays...and it is by no means a "quiet"
system.
-Toth
I bought one with 10 bays back in '97-98 from
a local dealer for $120 or
so. I still use it for my workstation machine. Including the height added
by the casters, mine is 29 inches high. Cases this size don't really fit
^^^^^^^
When you get up to a dozen or so drive bays, does it start becoming a
REAL computer? 
7:26 p.m.
New subject: Big PC boxes (was: SCSI Bus Problem?
On Mon, 11 Feb 2002, Tothwolf wrote:
I certainly make use of the extra bays...and it is by
no means a "quiet"
system.
My PC is loud, but I like it that way. It lives in my bedroom, and its
soft, constant noise helps me go to sleep at night. Heck, I recently
added two of those 'hard drive coolers' (3.5"-to-5.25" bracket and a
grill
(holding 3 fans) to replace the bay cover) just to increase the noise.
Hey, it keeps my system cooler, too!
That machine now has 12 fans in it of some sort or another. That much in
an ATX mid-tower case.
--
Jeffrey S. Sharp
jss(a)subatomix.com
12 Feb
12 Feb
3:14 a.m.
New subject: Big PC boxes (was: SCSI Bus Problem?
The say that long term exposure to high levels of white noise causes
insanity.
Well, that, or you start collecting old computing equipment...
--John
-----Original Message-----
From: owner-classiccmp(a)classiccmp.org
[mailto:owner-classiccmp@classiccmp.org]On Behalf Of Jeffrey S. Sharp
Sent: Tuesday, February 12, 2002 1:26 AM
To: classiccmp(a)classiccmp.org
Subject: Re: Big PC boxes (was: SCSI Bus Problem?
On Mon, 11 Feb 2002, Tothwolf wrote:
I certainly make use of the extra bays...and it
is by no means a "quiet"
system.
My PC is loud, but I like it that way. It lives in my bedroom, and its
soft, constant noise helps me go to sleep at night. Heck, I recently
added two of those 'hard drive coolers' (3.5"-to-5.25" bracket and a
grill
(holding 3 fans) to replace the bay cover) just to increase the noise.
Hey, it keeps my system cooler, too!
That machine now has 12 fans in it of some sort or another. That much in
an ATX mid-tower case.
--
Jeffrey S. Sharp
jss(a)subatomix.com
5:59 a.m.
New subject: Big PC boxes (was: SCSI Bus Problem?
Jeffrey S. Sharp wrote:
On Mon, 11 Feb
2002, Tothwolf wrote:
I certainly make use of the extra bays...and it is by no means a "quiet"
system.
My PC is loud, but I like it that way. It lives in my bedroom, and its
soft, constant noise helps me go to sleep at night. Heck, I recently
added two of those 'hard drive coolers' (3.5"-to-5.25" bracket and a
grill
(holding 3 fans) to replace the bay cover) just to increase the noise.
Hey, it keeps my system cooler, too!
That machine now has 12 fans in it of some sort or another. That much in
an ATX mid-tower case. from the same power bar as the internal 300 watt power
supply. I
use a power bar "rescued" from a DEC cabinet used for RL02
drives.
This keeps the discussion on topic since the power bar is 20 years old.
I have a 300 Watt power supply in my "big" box to supply 9 of the drives,
but I drew the line at that point. I use a separate ordinary PC power
supply to power the SCSI hard drive with their own 3 1/2" fan as well.
The latter two items were "rescued" from a box that was used to power
4 ESDI 5 1/4" full height drives, so I presume it has sufficient power to
run the three 3 1/2" SCSI hard drives and a bit to spare.
Also, eventually, I want to add 2 more EIDE drives to the system, so
the current 9 drives will become 11.
Question: Since the rest of the drives will be CDROMs and floppy
which will be rarely used and certainly not all at once, will 4 EIDE
3 1/2" Maxtor drives be too much when combined with the other
2 IDE CDROM drives, 2 SCSI CDROM drives, 2 floppy drives
and 1 SCSI Zip 100 drive?
Question: Can anyone see any problem with using a separate PC power
supply for the SCSI hard drives?
Question: I may also switch the 2 SCSI CDROM drives for SCSI
3 1/2" hard drives. If so, can I still power them from the internal
power supply or should I switch to the outside power supply?
Otherwise, that would make 6 hard drives in total on the internal
power supply.
Question: Is an additional ground wire between the separate PC
power supplies needed or recommended or even helpful when
the AC 110 volt supply is from the same power bar? The ground
wire would connect the frame of the "big" box with the case of
the external power supply.
6:32 p.m.
New subject: Big PC boxes (was: SCSI Bus Problem?
On Tue, 12 Feb 2002, Jerome Fine wrote:
Jeffrey S. Sharp wrote:
One PC power supply. It's either 250W, 275W, or 300W. I'm not sure which
one.
My PC is loud, but I like it that way. [...] That
machine now has 12
fans in it of some sort or another. That much in an ATX mid-tower
case.
What do you do for power in your system? This keeps the discussion on topic since the power bar
is 20 years old.
Hehe. My grandmother is over 20 years old, and she bought my first PC.
I am on-topic as well.
Also, eventually, I want to add 2 more EIDE drives to
the system, so the
current 9 drives will become 11.
Egad.
--
Jeffrey S. Sharp
jss(a)subatomix.com
11 Feb
11 Feb
3:24 p.m.
On Mon, 11 Feb 2002, Zane H. Healy wrote:
Where are you two finding cases with 10 half-height
5.25" drive bays?!?! I
had a nightmarish time a little over a year ago finding one with just 6
bays! The other question is, how tall are these cases? My 6 bay one barely
fits under the desk.
How many do you want? And it won't fit under the desk....
Doc
3:59 p.m.
On Monday 11 February 2002 21:24, Doc wrote:
On Mon, 11 Feb 2002, Zane H. Healy wrote:
> Where are you two finding cases with 10 half-height 5.25" drive
> bays?!?! I had a nightmarish time a little over a year ago finding
> one with just 6 bays! The other question is, how tall are these
> cases? My 6 bay one barely fits under the desk.
Spent the weekend taking apart hotswap units with 24 drives in each. A
pair of them would have made nice ends for a desk.
6:14 p.m.
Zane H. Healy wrote:
On Mon, 11 Feb 2002, Jerome Fine wrote:
Sellam - this one is racked in a tower box as well with TEN 5 1/4"
half height drive bays - is that what you are using? I can't begin
No, I have
10 half-height 5.25" drive bays. 10 full height would actually
be 20 half-height, which would be insane :)
1:15 p.m.
On Tue, 12 Feb 2002, Jerome Fine wrote:
Perhaps it was luck or just foresight that both Sellam
and I have these
For me it was tenacity. I was determined to eventually do something with
this stupid box, dragging it around with me through more than a few moves
for the past ten years, and I finally came up with a worthwhile use for
it.
boxes. As for size, 26 1/2" high (I left off the
casters, so it would fit
under a desk without a keyboard drawer), 17 1/2" deep (OK so it
will be tight on a small 20" desk) and 8 1/2" wide. So a BA23 box
without the plastic skin is much smaller - although perhaps that is not
a fair comparison.
Mine has no casters, but it just barely fits under a table of standard
height. I'll have to get measurements on it, but it's pretty big. Not
gargantuan, but as PC tower cases go, it's pretty gordo.
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
* Old computing resources for business and academia at www.VintageTech.com *
8192
days inactive
8193
days old
47 comments
17 participants
participants (17)
-
cisin＠xenosoft.com -
Diff＠Mac.com -
doc＠mdrconsult.com -
edick＠idcomm.com -
foo＠siconic.com -
geoffr＠zipcon.net -
ghldbrd＠ccp.com -
healyzh＠aracnet.com -
jcwren＠jcwren.com -
jhellige＠earthlink.net -
jhfine＠idirect.com -
jhfine＠postoffice.idirect.com -
jss＠subatomix.com -
kenziem＠sympatico.ca -
rhb57＠vol.com -
tothwolf＠concentric.net -
vance＠ikickass.org