How do I get DOS to recognize a scsi hard drive that linux can find and
partition (and format for linux)?  The controller card comes with a
utility that recognizes the drive (on ID 1, tho I set the jumper to ID 0)
and lets me set it to boot from 1, the computer does scsi boot, but right now
I only want to format it.  Linux fdisk finds it, DOS fdisk does not.  Linux
mke2fs formats a linux partition that I made on it with fdisk.  Three DOS
diagnostic programs don't find any non-IDE drives.  I have aspi8dos.sys loaded
high (and it workswith scsi zip and CD-ROM drives).  We found 5 scsi drives
and I got one working with linux, but also want to switch DOS to scsi on a
computer with bad IDE controller. IN theory I should not need a driver for
the hard disk.  aspidisk.sys is for removable storage devices.  This isa WD
2GB drive wtiha little green adaptor card to which you attach data and power
cable, and with which you set ID using a jumper.  
Linux seems to run faster in scsi.

59 responses total.

Perhaps the SCSI card doesn't have a SCSI BIOS?  If you installed Linux
to the drive would it boot Linux?  If not, I suspect it is a
non-bootable card which will work fine with CD-ROM/zip/etc, but won't do
a disk.  Linux has better innards, and will talk to a disk on one of
these, but only after booting.

I have been able to install linux to a similar drive (in a different computer
with the same SCSI controller card) and boot linux.  What I cannot do is
format the partitions on this disk with DOS format.  I can low-level format
it with the scsi card's utility.  I will look for a way to format the disk
for DOS with some linux utility.  Maybe format under dosemu?

I formatted with mkdosfs and DOS still does not find the scsi partitions with
drive letters.  How does one access a scsi hard disk with DOS?
syschk, hwinfo, and nssi find the scsi controller, cd-rom drive, and hard
disk, but don't mention drive letters.  0,1,0 is the hard disk (0 - cd, 7
-card).

What if you use linux to remove all partitions from the disk, and then
boot a dos floppy with fdisk and format on it?  Then make partitions
from dos.  Does that fail?  Dos fdisk can't handle partitions other than
dos, so if there are linux partitions on the drive dos fdisk will refuse
to handle them.  Also you'll want to use the dos 'fdisk /mbr' command to
make a boot sector.

I can't access the scsi drive from DOS.  I can partition it and format it for
DOS from linux.  DOS does not assign it a drive letter - should it?  I have
not used scsi disks in DOS.  I made the first DOS partition bootable in DOS,
using linux fdisk.  I will try the same drive with my other scsi computer in
case the card is having problems, or another drive with this computer, some
day.  I can't use dos fdisk /mbr on a drive that dos fdisk can't find.  It
was originally an Apple scsi disk but linux finds it.

If it was originally an Apple disk I wouldn't be surprised if it doesn't work
in DOS. Apple and DOS use two different partitioning systems, and I'm not
surprised if Linux fdisk can handle both (especially if you're using a
"standard" kernel that came with a distribution, because it's likely to
have support for that partitioning scheme built in), but DOS probably
can't handle the Apple partitioning system.
 .
quit

After I repartitioned it with linux, is there some trace of Apple partition
left to confuse DOS?  I removed any original partitions and put on  DOS
partitions.  Maybe it is the fact that my fourth partition is linux that is
confusing DOS?

If my hunch that Linux fdisk can handle both partitioning schemes is correct,
removing any existing partitions doesn't change the partitioning scheme. 
The last partition being Linux doesn't have any effect, any more than 
having two Linux partitions on an IDE disk with a DOS partition has any
effect. The only way to get at it, unless the partitioning scheme is built
into the hardware (I don't know if this is possible), is to *low-level*
format the disk. (If you've already done this, I have no further advice.)

 .
 help
 quit

I did low-level format the disk, with the scsi utility on the scsi card.
I will try it in another computer with a different card before giving up,
then a different disk.  So far two disks work in linux on two computers.

Who needs (MS-)DOS anyways? Linux is better, and surely some other DOS would do
just as well for whatever you need a DOS for?

Oh, well -- it was worth a try.

I like to use Wordperfect on a TTL monitor.  DOSemu does not support
console-mode Wordperfect (AltFn keys don't work as intended and if I try
xdosemu instead they crash X).  Linux does not even support TTL underline.
DOSemu does not support upper ascii characters.  BOCHs is said to.  DOSemu
Ctrl plus arrow keys does not work either.  I can also get online about 1
minute faster using DOS (turn on computer, boot, use kermit to dial grex, use
lynx faster at grex than directly via TCP/IP connection).   DOS boots faster
than linux so I use it to check mail.  I can't figure out how to print my
mails at grex from linux but it works perfectly with DOS, even if I telnet
to sdf I can print mails from there via grex.  I use linux for graphical
browsing (Opera or links2 graphical), image manipulation, streaming audio,
scanning.

Are you sure that when linux is making dos partitions that they aren't
really fat32?  The partition type number you are looking for is either 4
or 6 depending on the drive size.  4 for <32MB, 6 for <540MB.  Any other
partition type number is not going to show up with a drive letter in
DOS.  Although I think DOS fdisk should find those other partition types
as "non DOS partition type"  and refuse to touch them in any way.  But
sounds like you are getting the "no fixed disks present" error from DOS
fdisk.  SCSI has standard command to give the media, so Apple shouldn't
matter in that respect.  And it is just media, so after a low level
format it should not have any remnant of apple bits stored on the media
to confuse DOS.  Kinda like plain white paper from Apple is compatible
with Okidata printers.  ;)  If the SCSI card was from Apple, though. 
I'm sure that won't work except in Linux.

I am making FAT16 partitions, according to syschk.  On this first computer,
syschk, hwinfo and nssi all found the drive as 0,0,0, but DOS did not assign
it any drive letters despite having three FAT16 partitions.  I had used the
internal scsi CD-ROM drive as terminator.  I finally found an internal scsi
cable with terminator to use in my other computer that has the same model
Adaptec scsi card with external CD-ROM drive (it refused to work when I took
it out of its case, though two others had cooperated and let me set them to
ID 4).  Eventually I got everything plugged in and running (I had to unplug
the external scsi cable or it would look for the external scsi hard drive,
which was not turned on, and refuse to boot).

This second computer, which is one Scott gave me (with bad onboard IDE primary
slave IDE and floppy controllers which I replaced with an I/O card), is
somewhat newer, a DFI, 533MHz (the cpu would only work reliably at up to
500MHz), like the first one (a 200MHz Soyo), can also be set to boot from SCSI
(and A: C: D: E: F: ZIP100 and CD-ROM).  It is a year or two newer.

Using the same drive with the same partitions (which linux found again),
hwinfo and nssi found the SCSI controller but NOT the drive itself.  The
Adaptec controller eventually found the drive (once I got the jumpers correct
and the scsi cable plugged into both card and drive, with terminator).  Syschk
found the drive and IT ASSIGNED IT DRIVE LETTERS!  The first IDE drive (four
DOS partitions) is C E F G and the scsi drive is D H I.  

So either the motherboard/BIOS or the actual scsi controller card is the
problem and I will put the 2GB drive in the second computer for DOS and for
playing with uclibc, and the 9G drive with three linux partitions (which I
am currently formatting with linux) for my little linux and for some later
version of Slackware (9.1?) and space to copy music CD's to and make MP3s.
Jim just fixed the DVD player that i gave us, which plays MP3s.  And he also
just acquired a 3MP digital camera which should help use up disk space.  

Scott gave us a Tyan dual 450MHz server motherboard with two onboard scsi
controllers but no case - does anyone have a huge ATX case they don't want?
We could put all the scsi drives in there and start our own bbs.  The previous
grex (SunOS) used a lot of 2GB scsi drives but they were much larger.  

Anyone want to try to explain the advantages of scsi?  From what I read, there
are none for DOS, or for linux except if you have more than one scsi drive
and are running several processes at once, using both drives (such as running
a BBS or other server).  

This response has been erased.

SCSI doesn't have a lot of advantages for desktop use, in my opinion.  
(There are probably people who will strenuously disagree with me about 
this.) 
 
SCSI is a big win when you need lots of drives in one machine.  Its 
architecture allows you to daisy-chain several drives (just how many 
depends on the type of SCSI) instead of just two in IDE.  Some versions 
also offer faster throughput than IDE.  Unlike IDE, the SCSI bus can 
also be extended outside the computer case for external drives, 
scanners, etc.  There are some rumors that SCSI drives are built to 
higher mechanical standards and are more reliable, but I'm not too sure 
about that.  They're certainly more expensive. 
 
Besides the expense, SCSI has some gotchas in setup -- you have to use 
good quality cables, make sure the cables aren't too long, and 
terminate properly at both ends, or you'll have mysterious problems 
that can be really hard to troubleshoot.  There's a lot of 
poorly-designed low-end SCSI hardware out there, making it even 
trickier.  You often need special drivers to properly use SCSI drives 
from DOS, as well, and if the card has no BIOS (cheap cards intended 
for scanners or tape drives are often this way) you may not be able to 
boot from it. 
 
It's starting to look like SCSI will be largely replaced by SATA for 
internal devices, and Firewire and USB 2.0 for external ones. 

Yesterday my scsi CD-ROM drive developed some sort of problem which prevents
DOS from booting in a third computer, and slows down linux boot (I think it
eventually disables that device and finishes booting).  Is this a failure of
the drive electronics?
scsi0:A:2:0): parity error detected in Data-in phase.......
Then Dump Card State Begins (lots of SCSI and SEQ and SCB stuff) and Ends
scsi0:0:2:0:  Device is active, asserting ATN
REcovery code sleeping
Recovery code awake
Timer expired
...attempting to queue a TARGET RESET message
and more parity error detected.
scsi0:A:2:0: Unable to clear parity error.  Resetting bus.
scsi:  device set offline - not ready or command retry failed after bus reset

0:2:0 is the CD-R burner that we got when Kiwanis threw it out, and took out
of its external case and installed internally.  I burned 10 or so CDs with
it successfully, then it was not working which I thought was something I had
done (it would burn 80% of any CD) then it worked fine again.   Should we try
cleaning and lubricating or just give up on the drive (which is our fastest
burner - we can try to clean the 2X again instead).  Genuine HP.multiread,
burns at 8X or so.  dmesg did not identify it due to the parity error.

If this is in one of the computers you used to test, I would make sure
that the scsi bus is put back together correctly.  Termination problems
might give such errors.  If not, then it becomes less clear. 
Terminators die sometimes.  Both ends of the scsi bus must be
terminated.  Most people have the adapter as one end of the bus.

I think there is some thing I did to the drive itself to terminate it
internally, and I have a scsi zip drive set to terminated on the external
connector.  I will check the internal terminator, thanks.  

In the computer where the internal scsi hard disk is not recognized, maybe
I don't have the CD burner correctly terminated.  I don't know if I ever used
it.  That drive is recognized, the hard drive is not.  

In the third scsi computer, I know I put a terminator on the hard drive, and
the cd rom drive is external and plugged in before the terminated zip drive.

How does one normally terminate a CD-ROM drive?

CD-ROM drives usually had a jumper that would activate a built in
terminator.  Some had a pair of resistor packs you could put in.  They
look like a 1 inch by 1/8 inch blob of dried epoxy paint, usually red or
yellow, with a single row of about 8 or 10 pins.  They did it that way
as terminators sometimes burn out and need replacing.  If neither of
those are possible through lack of markings, or the resistor packs
missing from the socket, then move the drive elsewhere on the cable, or
get a terminator that connects into the drive connector on the cable.

I don't have a terminator for my cable or know where to get one.  I think I
should probably just replace the drive with parity error, but first I will
check the one that is working to see what happens if I take off the terminator
- will it give the same symptom?  Thanks for the info.  It gives me more to
experiment with.  Right now I am dealing with an MGA card that suddenly
starting displaying garbage (lower ascii wrong characters) and is interfering
with use of the onboard parallel port (tho I think I disabled the parport on
that card).  Simple solution is to replace it.  And a modem that hangs up in
3-13 minutes of when I dial and then won't dial again at all.  Same computer.
THe other computer has the CD-ROM parity problem.  I am trying to do and send
a job between the two computers.

Anyone know what it means if a computer boots some of the time, and maybe
boots more often if there is not a second video card in there (TTL), and if
it cold boots, then it will not warm reboot, starting yesterday?  Is it
possibly the power supply being overloaded and less load without the second
card?  I could unplug the CD-ROM drives as an experiment, or the 5.25" floppy
drive.  I think this is a 200 or maybe 250 watt supply and I have two hard
drives, two floppy drives, a CD burner and a CD-ROM reader, powered sound
card, TTL card was removed, PCI video card, ethernet card, internal modem
(which could be changed to external).  We have other power supplies to replace
it with if necessary.

Thst could be power overloading.  As to SCSI, the errors are notoriously
inconsistant given a particular error condition.  Parity errors and
drives not detected are both common with termination problems.

The CD burner has a jumper on it that you put on to terminate it.  I don't
know what I can do to fix it so we just removed it and will test it one more
time in the other computer which is booting properly with a different scsi
CD-ROM drive.    The boot problem started after putting in the internal modem.

We tried the same burner in another scsi computer, where it also prevents DOS
from booting past the scsi stage and slows down linux, which decides not to
pay any more attention to the burner.  Out it goes, along with the 2X which
you can't boot from and which linux can't find.  Nice sturdy NEC model.  Then
there is a 48X that won't play music, which is fine for Jim who has no sound
card either.  And a laptop computer with a green Accupoint mouse device that
works in DOS and DamnSmallLinux as /dev/psaux but in our little linux the
pointer scoots to the upper left as soon as you touch the mouse, and stays
there.  I tried 'no_accel', and a newer kernel.  X_SVGA, which works with mice
in other computers.  Serial mouse works.  External PS/2 same as the erase
type.  

Re #16: As I understand it, FireWire is just a serial
  hardware layer to run the SCSI protocol over.  It's
  certainly more convenient than traditional parallel
  SCSI and is fast enough to be useful.     

Re #19: Generally a CD-ROM drive will have a termination
  jumper.  Unless the CD-ROM drive is at a physical end of
  your SCSI chain, its termination should be disabled.

If the same combination of host adaptor and hard drive work
one machine, but not in another, it's possible that the 
working machine includes NCR BIOS extensions in ROM that
enable it to recognise and boot from the SCSI drive.

Partitioning and making a filesystem ("high level
formatting" in DOS-speak) makes sense, but you should almost
never have to low-level format a SCSI or ATA ("IDE") drive -
certainly not for something as trivial as removing a
partition.

...or rather NCR BIOS extensions would enable the firmware
to recognise the host adaptor and boot from a hard disk
attached to it.

We now have THREE computers with scsi controllers (one is onboard) that will
not boot from a scsi hard disk, only two of which even assign it a drive
letter in DOS when I load DOS drivers.  We will use IDE for DOS on the primary
controller, disable the secondary controller, and put linux on scsi disk. 
That at least frees up one IRQ.  DOS and an IDE CD-ROM drive on one
controller, linux and SCSI CD-ROM burner on scsi controller, external zip
drive and scanner on same scsi controller.  The scsi computer we were working
on just got lent to a friend for a month because she had to run some data
acquisition software written to only work with XP (which still took an hour
to load on our best computer).

Check if the SCSI ID's on the host controller and one or more of the devices
are identical. They should all be different, and the host adaptor's should
be the highest.

We did all that.  Controller is 7, scsi drive is 0 or 1 (we tried to use two
together and it did not work at all), CD-ROM drive 3 or 4, no scanner or zip
drive even plugged in.  I think the BIOS is simply not set to boot from scsi
drive, even though you can set it to that.

What kind of host bus adaptor (the thing you're inaccurately
calling a SCSI controller) are you using?  Perhaps it's chip
-set isn't the one that your PC's firmware (commonly but
inaccurately called the BIOS) includes support for.  Ask Jim
if the host adaptor shows any obvious signs of a ROM or
EPROM.

It is Adaptec and uses aic7xxx.o driver module.  We have three such cards,
and also one motherboard with onboard adaptec controller using aic79xx.o for
which I will need to compile a different kernel.  The BIOS really ought to
include support for the onboard scsi chip, I would think.  

Am I correct in thinking that the machine that's unable to
boot from a SCSI drive is not the same one with a SCSI host
bus adaptor integrated into the mainboard?

Maybe. Even PCI SCSI controllers let you boot from them.

/Some/ PCI host adaptors are bootable on a PC, either
because they carry their own on-board BIOS extension ROM, or
because the machine's firmware happens to include support
for the chipset used.

If keesan's PC has NCR SCSI support in its firmware, but her
host adaptor uses an AIC chipset (and has no on-board BIOS-
extension ROM), she may be able to use it, but will not be
able to boot from it.

An important difference between DOS and things like Linux is
that DOS works via BIOS for disk i/o.  A consequence of this
is that a ROM-less host adaptor that's not supported by the
firmware might work fine in Linux (without being bootable)
but might not work for DOS.

I cannot boot from a DOS scsi drive on two computers with SCSI cards, and on
the computer with onboard SCSI support.  One of the former and also the latter
recognize the DOS drive as C: if I load a DOS scsi driver, the other won't
even do that (it is older).  They all work with linux SCSI drive if I don't
boot to it directly but via loadlin using a scsi-capable kernel, which is what
I will be doing.  The onboard scsi computer is dual-450MHz and if I set things
up right is supposed to compile nearly at 900MHz.  But it is out on loan, in
a garage running XP (what a waste).  

Strange.  When you made the DOS partition and wrote a new
filesystem on it, did you leave the first track of the drive
free for the master boot record?

I did a low-level format with the scsi utility, partitioned with DOS fdisk,
and formatted with DOS, as usual, putting on system files.  format /s I think.
Whatever I did works with IDE but not SCSI, for booting.  Do you need to
format and sys SCSI drivers differently?

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