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alisdair010799

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SCSI problem

I have two PCs. One is older than the other in terms of hardware. I have a SCSI controller and a CDROM-RW and a TRAVAN tape backup device(both SCSI). In the old machine everything(SCSI) works perfectly. In the newer machine writing to the CDROM-RW or TRAVAN device will fail(sometimes at the beginning/middle and end, there is no pattern). There are NO error messages. Please help.
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bassque

make sure only the device at the end of that scsi chain is the terminated one.
If there is another device in the scsi chain that is terminated bu accident or if you added the cdrw to this machine and it was terminated in the old machine, that could be the problem

good luck
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Could it be that you have more software running in the background on the newer machine ?
Did you check to see that in both machines the device is set up the same.
Since CD writing is very sensitive, I would use Start up Cop to remove selectively, whatever you do not need at startup.
download the Startup COP a free pcmag utility from
                     http://www.zdnet.com/pcmag/filters/downloads/0,9077,6008597,00.html

 Run it and it sill show you everything that is listed in all the possible startup places and allow you to disable what is not critical.

I hope this helps.
More information would be helpful. SCSI controller type, etc...
Have you scandisked and defragged your staging area?
bassque has a good point also. Make sure that your SCSI chain is terminated properly.
when you boot the machine, does the scsi utility list the devices?
Is the order of the SCSIs the same on both machines? Sometimes the SCSI ID makes a difference.

Om my Dell, I have a SCSI hard drive, CD-ROM, CD-ROM/R, and a Seagate Tape Drive. The ID order was important.

My IDs are:

0 - Hard Drive
2 - Tape Drive
4 - CD/r
5 - CD-ROM

Avatar of alisdair010799

ASKER

All SCSI divices have their own unique IDs. SCSI controller(7), tape device(4) and CDROM-RW(3). The tape contoller is the middle device(termination DISABLED), the contoller and CDROM-RW are properly terminated(ENABLED). I am using an IWILL(ULTRA) SCSI contoller, a Seagate Tapestor Travan and a Yamaha CDROM-RW. On the new machine where the problem occurs I have tried NT and 98. Both experience the same problems as described above. On the older machine I've also tried NT and 98 with no problems. There are no IRQ, IO or memory address conflicts. I ran the diagnostic software on the controller with no errors. I've tried with only ONE device(ie contoller and either tape OR CDROM only, with the appropriate termination) and the problem still occurs. I have also removed all uneccessary cards and tried all the PCI slots for the contoller(no luck). My old machine is an Intel 166mmx + 128M. My newer machine is INTEL Celeron 433 + 128M. This is not an intermittent problem.
Did you check the properties of the SCSI controller and CD-RW on both machines to see that they are set up the same. This could be either an IRQ or even a DMA problem. Make sure the SCSI controller is NOT using IRQ 2 or 9, and that it is on a SEPERATE IRQ, not shared with anything else.Check the CMOS-BIOS setup and load the defaults.
That's all for now.
The ID of the SCSI has something to do with the priority of the device. Wheni I installed the tape with a higher number, it knocked out the CD-ROM or CD/R. The lower the number, the lower the priority. When I gave the tape a number LOWER than the CD-ROMs, they began to work properly.
Will either device work properly if connected without the other?  Or will they work if connected in a different order? Are the connectors all the same or are you using adapters. Did you switch scsi controller cards between computers?  
It is exactly the same hardware I am moving between both systems. Neither device works properly with OR without the other (this rules out ID prioritisation, ie only the CDROM-RW is connected). IRQs are OK. It seems like the SCSI controler card just stops working. It has an LED which goes dead.
Have you run the SCSI setup config within the SCSI CARD 9 on Adaptec controllers it is Ctrl-A ) ? Maybe you have to change one of the settings ?
I've had a look at the card's config. It seems ok. It works with the same settings in my older PC. I am begining to suspect the motherboard, although I have othe PCI cards that have never given a problem only the SCSI card which is OK.
I've worked out the problem. The question is still open. There are no hardware/software faults. It is a setting this SCSI card does not like. I don't want to give it away so here is a clue. Think of a CYRIX CPU. I am not using one, but it is a decent clue(I think). Also, I am not sure if other makes of SCSI(PCI) cards are prone to this problem.
Is it a cache setting ? Write thru vs. write back ? Also CYRI had problems with internal cache on or off. In any case, I'm glad the problem is solved.
It's not a cache problem. It seems to me to be a synchronisation problem for the SCSI card. On a few systems this setting is set in the BIOS(motherboard NOT SCSI) for most it is not. The latter is the way I changed this setting. This is an easy clue. This is starting to sound like a riddle. I just don't want to delete the question. Another clue (very easy). Improving performance without buying new hardware.
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The points are yours although your answer is not entirely correct. Although if I still hadn't solved the problem your answer would have jogged my memory. Basically, a few weeks before putting the SCSI card into my newer machine I changed the bus speed from 66Mhz to 75 Mhz. Some cyrix processors use this bus speed. At 75MHz the backup or writing process ALWAYS failed, albeit at different sages. At 66MHz I have no problems.