Just a random idea, since I have very little experience with SCSI. Is the cable terminated on the card's end? I once had some issues that were resolved by properly terminating the bus on both ends (the other end was a disk with internal terminator pack, like what you have).

Have you tried to check whether your DMA transfer speed of your Adaptec controller is too fast?
(You can repeat your test in the lowest speed)

SyQuest SQ3270S is a narrow SCSI 1 device, the Adaptec 1540/1542 is SCSI 2. You need to set the maximum rate to the SyQuest to 5Mb/s in the SCSI Select.
Also make sure you have Term Power enabled and the Adaptec is also terminated since you have only the external device.

SQ3270S uses passive termination.

To find the error you may try asynchronos transfer mode too.

Deunan wrote on 2021-10-12, 20:55:

Just a random idea, since I have very little experience with SCSI. Is the cable terminated on the card's end? I once had some issues that were resolved by properly terminating the bus on both ends (the other end was a disk with internal terminator pack, like what you have).

Horun wrote on 2021-10-12, 23:17:

SyQuest SQ3270S is a narrow SCSI 1 device, the Adaptec 1540/1542 is SCSI 2. You need to set the maximum rate to the SyQuest to 5Mb/s in the SCSI Select.
Also make sure you have Term Power enabled and the Adaptec is also terminated since you have only the external device.

AHA-1540C is AFAIK auto terminated by default and I havn't changed this setting.

Disruptor wrote on 2021-10-12, 20:59:

Have you tried to check whether your DMA transfer speed of your Adaptec controller is too fast?
(You can repeat your test in the lowest speed)

Yeah, that crossed my mind but I was too annoyed to check it yesterday. I will check it as Horun and you suggested. Thanks.

Disruptor wrote on 2021-10-12, 23:29:

SQ3270S uses passive termination.

To find the error you may try asynchronos transfer mode too.

It has a row of jumpers installed on the PCB so I guess it is terminated, but I couldn't find any manual for it... Also on the external enclosure it states to NOT use the terminator switch of the enclosure (I guess the reason is the drive itself has termination enabled).

Edit: I checked the adapter settings and it's set to default 5MB/s although the problem may be because this particular machine has GUS and ProAudioSpectrum cards and network adapter and a weird promise VLB IDE controller and it's not that stable to begin with (hangs up on most things using the sound cards) so I may definitely check it on my other system which is not as congested. I also noticed that even if I don't try to access the drive after a soft reboot (ctrl+alt+del) the controller won't find the drive giving me the timeout...

The layout and jumpers for the SYQUEST SQ3270S (internal drive, not the external enclosure) is here:
http://computermuseum.informatik.uni-stuttgar … h/5000/4550.htm

Horun wrote on 2021-10-13, 22:52:

The layout and jumpers for the SYQUEST SQ3270S (internal drive, not the external enclosure) is here:
http://computermuseum.informatik.uni-stuttgar … h/5000/4550.htm

Thanks! So yeah, it seems the jumper block I've seen yesterday is indeed a terminator. I will make a picture tomorrow.
I just played around some more with the SCSISelect settings, but the problem remains - Timed out waiting for I/O completion (target 5) CDB: 12 00 00 00 24 00 - 5 is a current SCSI ID of the SQ.

I guess I will try different machine, possibly with a different controller.

I managed to make it running with AHA-1540B installed in my 286. Reads/writes to the drive properly. Unfortunatelly it seems that only disk I have has a lot of bads, so I can't confirm it's working 100% correctly.

I'm pretty sure AHA-1540C in my 486 has some DMA conflicts - likely with GUS or PAS card.

You may use the SQPREP.EXE tool to relocate bad sectors.
But if your disk has too many of them, it may refuse to work.

I use an Adaptec 1542B too in my 386sx since I have had problems with a 1542CF.

Disruptor wrote on 2021-10-16, 17:04:

You may use the SQPREP.EXE tool to relocate bad sectors.
But if your disk has too many of them, it may refuse to work.

I use an Adaptec 1542B too in my 386sx since I have had problems with a 1542CF.

Do you have any idea where I can find SyQuest software suite? I have a hard time finding it. I found some tools/drivers for Windows 95 but not for DOS 🙁

Edit: I found it searching by "sqprep.exe" 😁 http://ftp.mpoli.fi/pub/unpacked/hardware/hdd … st/sqprep21.zip

Edit 2: But I can't use sqprep anyway because it requires Adaptec BIOS to be enabled and syq55.sys loaded, but I had to disable Adaptec BIOS as it conflicts with XT-IDE no matter which settings I choose and I have to use aspi4dos and aspidisk drivers instead...

It just requires the ASPI driver. Perhaps your tools are too old.
SQDRIVER.SYS from 1994, SyQuest Device driver 7.62
SQPREP.EXE from 1994
It supports the SQ555 and SQ800 drive as well as the SQ3105 and SQ3270 drive.
I don't know whether non SCSI SyQuest drives are supported.

You do not need to load the SQDRIVER.SYS when your SCSI BIOS or ASPIDISK.SYS already has created a drive letter.

Sounds good Disruptor ! I was going to suggest using a floppy disk with the files and disable the XT-IDE, enable Adaptec BIOS and see what happens with SQPREP.
If it relocates sectors properly, then go back to original configuration but using older Apsi driver could easily be part of the issue.

Thanks. I will check this out. I also tested my other SyQuest drive (SQ555) with a single 44MB disk I have and it worked allright. No bad sectors on the disk at all! Also it's very fast compared to the IDE hdds of the similar size.

Edit: Yes, this version of SQPREP works nicely just with aspidisk.sys driver, thanks!

HanJammer wrote on 2021-10-16, 18:14:

Edit 2: But I can't use sqprep anyway because it requires Adaptec BIOS to be enabled and syq55.sys loaded, but I had to disable Adaptec BIOS as it conflicts with XT-IDE no matter which settings I choose and I have to use aspi4dos and aspidisk drivers instead...

Adapter BIOSes are loaded in the order of position in address space. Try to play with the adapter BIOS addresses.

Disruptor wrote on 2021-10-16, 20:20:

Adapter BIOSes are loaded in the order of position in address space. Try to play with the adapter BIOS addresses.

Yeah, I know that and I did that. But after trying almost all combinations I gave up. But to be honest I don't really need that as finally everything worked perfectly good with adaptec bios disabled. Tomorrow I will move the 1540C to the Pentium machine and I will check if it works with the 3270 there - if it does then I'm good (I need it because somebody needs help with recovering data from some 270MB SyQuest 'diskettes' - hopefully they were not formatted with some exotic filesystem - just FAT16 or 32.

That is great Hanjammer ! I found some archives of 2000-2003 Syquest files including updated drivers from 1997 and FAQ's that may help later if you have issues.
There is a Win95 Backup util from Syquest you might need if those 270mb were encoded under Win9x, they are on the Win95 driver disk.
Will try to post them to Library or the links here after verifying the archives are good.

added: very odd that many of the older SyQuest drivers and tools were never mirrored on the regular driver web sites...

Horun wrote on 2021-10-17, 01:25:

That is great Hanjammer ! I found some archives of 2000-2003 Syquest files including updated drivers from 1997 and FAQ's that ma […]
Show full quote

That is great Hanjammer ! I found some archives of 2000-2003 Syquest files including updated drivers from 1997 and FAQ's that may help later if you have issues.
There is a Win95 Backup util from Syquest you might need if those 270mb were encoded under Win9x, they are on the Win95 driver disk.
Will try to post them to Library or the links here after verifying the archives are good.

added: very odd that many of the older SyQuest drivers and tools were never mirrored on the regular driver web sites...

Yeah, I tried to download some from the archive.org but It didn't work. If you will be able to upload them to the library or at least some google drive - that would be really helpful!

Thanks!

I upped them here: http://www.vogonsdrivers.com/getfile.php?file … 6&menustate=0,0
found some of them here: http://web.archive.org/web/20031105091426/htt … 00-scsi.pc.html

Disruptor wrote on 2021-10-16, 18:56:

It just requires the ASPI driver. Perhaps your tools are too old. SQDRIVER.SYS from 1994, SyQuest Device driver 7.62 SQPREP.EXE […]
Show full quote

It just requires the ASPI driver. Perhaps your tools are too old.
SQDRIVER.SYS from 1994, SyQuest Device driver 7.62
SQPREP.EXE from 1994
It supports the SQ555 and SQ800 drive as well as the SQ3105 and SQ3270 drive.
I don't know whether non SCSI SyQuest drives are supported.

You do not need to load the SQDRIVER.SYS when your SCSI BIOS or ASPIDISK.SYS already has created a drive letter.

I have updated my Link with the SyQuest SQPREP DOS Tools Release 2.82, March 1994.