Problem setting up CDROM Drive with A2091

[sim]

Help... I'm running out of ideas!

I'm trying to get an Apple 600i SCSI CDROM drive to work on my A2000 using an A2091 card, but it's constantly locking up (a2091 access light goes on full making all disk access impossible).  The CDROM drive comes up ok in all the SCSI interegation tools, and I can send it scsi direct commands to open and close, but even these will on occasion lock it up.  All this before I even mount it.  If I do mount it the icons appear in workbench, and I can open up a directory or two before it locks up again.

Is this indicative of termination problems or something else?

My setup is:
A2000 3.1 roms (workbench 3.1)
A2030 030/882@25Mhx with 4Mb Ram
A2058 with 2Mb Ram (actually has 4 Mb, but jumper set to 2)
A2320 Display Enhancer
Picasso II with 2Mb
A2091
 - unit 1 IBM DSAS-3360 450MB Hard Drive
 - unit 2 Matshita CDROM CR-8005A (Apple 600i scsi 2 drive)

Any ideas appreciated :-?

Cheers

[sim]

Forgot to mention that I'm using the standard scsi.device (version 40.37 I think, but would need to double check)

[machinehead]

Sim,
Make sure that you terminate the last drive with an active terminator. Check the SCSI address jumpers on each drive and make sure they are different, but neither one is 7.
SCSI 7 is the host, so you get 0 to 6 as addresses.
Termination is critical. Some SCSI drives have a jumper for internal term, check this. If not, buy a terminator.
Anyone else?
Dave

[sim]

Thanks for the suggestions.  Both the hard drive (unit 1) and the CDROM drive (unit 2) have powered terminators controlled by jumpers.  I have the CDROM set to terminate and the hard drive set not to.  They're both connected internally like this:

A2091 -> hard drive -> CDROM

I assume that the A2091 provides termination for its end, as I don't have anything connected to it externally.

There's no trouble with data access to the hard drive, only the CDROM seems to have issues.

Cheers

[machinehead]

Sim, Have a look at this. Look for SCSI controllers. It describes some problems with the A2091

http://www.amiga-hardware.com/

Good luck!
Dave

[AmiMan]

Your boot hard drive should be set for SCSI ID 0 with termination off.  The first CD Rom drive on the A2091s SCSI chain should be set for ID 3 with termination on.  Some Apple CD-Rom drives will NOT work with an Amiga computer because they were custom built for apple to only work on certain Macs.  Make sure the 3 resister packs are still soldered on the A2091 board next to the 50-pin ribbon cable connector.  If not then you will have to plug in an active terminator into the rear 25-pin SCSI port.  Here is the way the Commodore A2091 board reads the SCSI chain:  IDs 0 to 2 are for hard drives, IDs 3 and 4 are for CD Rom drives, and IDs 5 and 6 are for ZIP, Tape drives, etc.  The A2091 reads from SCSI ID 0 to 7, NOT from 7 to 0.  Also looking at your setup, if there is DRAM installed on the A2091 then REMOVE THEM!  You can only have up to 8 megs on the Zorro II bus.  The 4 megs of memory on Commodores A2630 card, even though it is concidered 32-bit memory, it is still part of the Zorro II bus.  I don't know why Commodore designed the A2630 board the way they did, but those of us that love this 68030 board have to live with it.  So, your A2630 board has 4 megs of Zorro II memory, your Picasso II video board has 2 megs and your A2058 has 2 megs.  So if there is memory on the A2091 board, this will cause some big problems.  If there is memory on the A2091 then just remove the A2058 card.  Remember, it is a computers memory that holds the actual program code, so if there are memory problems you WILL also have software problems.  Think about this and you will see how everything fits together and works together.

[Framiga]

Hi

this is the DM that i like . . . . useful, technically prepared (at least on A2000 system) and moderated.

Still so and you wiil be always the wellcome (IMHO)

Ciao :-)

[sim]

@machinehead

I had seen this, but it doesn't suggest anything that is definitely a problem.  It's always possible that upgrading the rom or scsi chip may help, but that's not easy to do so I'd rather know for sure it was the problem before trying to track down hard to find components.  (Not to mention I don't really want to throw a lot of money after such an old controller).

Thanks for the suggestion through.

Cheers

[sim]

@AmiMan

>Some Apple CD-Rom drives will NOT work with an Amiga computer because they were custom built for apple to only work on certain Macs.  

How do I know if this is one of those drives?


>Make sure the 3 resister packs are still soldered on the A2091 board next to the 50-pin ribbon cable connector.  If not then you will have to plug in an active terminator into the rear 25-pin SCSI port.  

Unfortunately I don't know what the resistor packs look like.  I've read about these being cut off to allow internal and external drives, but I haven't been able to find a photo with the specific components identified.  Any idea how I can confirm this?  I could post a picture of the board if someone can then point out the packs.


>Here is the way the Commodore A2091 board reads the SCSI chain:  IDs 0 to 2 are for hard drives, IDs 3 and 4 are for CD Rom drives, and IDs 5 and 6 are for ZIP, Tape drives, etc.  

That's interesting!  I've never heard this before.  I thought that any scsi device could be placed on any ID as long as it's unique.  In fact weren't the A2091's produced before CDROM drives were particularly common, let alone zip drives?  Still it's worth a try.  My hard drive is unit 1 at the moment and the CDROM unit 2, so I could try shifting the CDROM to unit 3 and see if it helps.


>The A2091 reads from SCSI ID 0 to 7, NOT from 7 to 0.

How does this affect things?  I assume that termination is interested in the physical order that the drives are chained, not the order that the unit IDs are set?  Am I wrong on this?


>Also looking at your setup, if there is DRAM installed on the A2091 then REMOVE THEM!  You can only have up to 8 megs on the Zorro II bus.  The 4 megs of memory on Commodores A2630 card, even though it is concidered 32-bit memory, it is still part of the Zorro II bus.  

Yup thanks, no memory on the A2091.  In fact I've already had to reduce the memory on the A2058 after installing the Picasso II board.


>I don't know why Commodore designed the A2630 board the way they did, but those of us that love this 68030 board have to live with it.  

I believe it was so that the memory was still available when you boot using the 68000 instead of the 68030.  Probably a good idea at the time (keeping backwards compatability) but a pain now as I really didn't want to go from 8MB to 6MB when installing the graphics card.


Thanks for the suggestions.  I'll try changing the CDROM unit ID and let you know how it goes.

Cheers

[darksun9210]

this is a resistor pack. ... or at least this is like one of the three i took of my warp engine card...

......dammit! how do i paste a picture in here? :pissed:

defeted by the simplest thing :lol:

lets try this...
google image search

yeah that works... its the small picture of a yello thing with a set of legs... (banana in suspenders?)

[Jope]

Ds 0 to 2 are for hard drives, IDs 3 and 4 are for CD Rom drives, and IDs 5 and 6 are for ZIP, Tape drives, etc. The A2091 reads from SCSI ID 0 to 7, NOT from 7 to 0.

Can you elaborate on that? Why does it matter what ID you set the rest of the devices to?

The disks should be found first so the controller will know when to stop looking (faster boot times), but the rest - it's all the same.

The only thing that might matter in some cases is higher ID = higher priority on the bus, but this isn't one of those cases. :-)

[BoingBoss]

I agree with AmiMan.  He sounds a lot like the DoomMaster, who knows what he is talking about when it comes to the Amiga and Atari ST computers.  If AmiMan is the DoomMaster then you should listen to what he has to say.

[JimS]

You're right, it makes more sense to have the HD first to speed up the boot time. Other than that, and the fact that the controller itself is at address 7,  there are no restrictions on using a scsi address for any type of device. Most of the 2091/HD combos I've seen had the HD set at 5 or 6 since the drives came that way - it's the best way to include 2 address jumpers.

[Piru]

@BoingBoss

You sound a lot like the DoomMaster, who doesn't know what he is talking about when it comes to Amiga and Atari ST computers.

He is a clueless pr*ck who cheats, lies, spreads misinformation and threatens adminstators with DDoS and hacking amiga.org. He has been banned from amiga.org and various other forums repeatedly.

[BoingBoss]

Hi Jope,

Can you elaborate on that? Why does it matter what ID you set the rest of the devices to?

It mainly has to do with the way Amiga software in general "sees" the SCSI devices.  It also has to do with Boot Priority.  Remember, the A2091 reads the SCSI IDs from 0 to 7.  So it is a good idea to have your hard drives first, then your CD-ROM drives, then your Zip or Tape drives.  As a good general rule SCSI IDs 0 to 2 are for hard drives, 3 and 4 are for CD-ROM drives, 5 and 6 are for zip or tape drives.