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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: fx on February 05, 2004, 02:00:34 AM

Title: Problems with A2090a and a SCSI disk
Post by: fx on February 05, 2004, 02:00:34 AM
Hi, I have an A2090a in my A2000 and at the moment a extremely slow 20MB XT Harddrive is connected to it.  I was planning on exchanging this with a slightly bigger (and faster!) SCSI drive but hasn't been able to get it working :( ..

Me and a friend spent many hours with this but without any progress. At first we tried a 240MB Quantum disk which we could not find any information about on the net, so we plugged the disk into another Amiga and read the information that we could get from HDToolbox and tried to feed that to the prep program (and mountlist.hd) but it got stuck as soon as it was gonna write everything to the disk.

After lots of battling with this we tried a smaller 50MB Quantum disk with the same results :( But for this disk we could find some information on the net about cylinders, heads and so on, but those didn't match with what HDToolBox told us at all. Anyways we tried using those values instead but it only lead to the same thing :(

Does anyone here have any experience with setting up a SCSI disk on a A2090a ? I would appreciate all help I can get :) sorry if this post got a little messy, I'm very tired right now and can't be bothered to read through it all again looking for errors and stuff  :-D
Title: Re: Problems with A2090a and a SCSI disk
Post by: shaf on February 05, 2004, 02:15:01 AM
Hello,

The A2090a was the Autobooting version of the A2090 SCSI Controller. At that time the biggest available Hard drives were 40 MB.  I never saw this card just the older A2090 version. When Kickstart/Workbench 1.3 was released CBM produced the A2091 SCSI Controller Card.

For some reason I seem to remember the A2090 primarily being used for MFM/RLL ST506 Type Hard Drives.

II migh have some older notes around in my old CBM Tech Note book but will have to do some digging to confirm my information.

Cheers

Shaf
Title: Re: Problems with A2090a and a SCSI disk
Post by: Jagabot on February 05, 2004, 03:33:29 AM
I think this link will help you a lot. :)

2090a guide (http://www.lysator.liu.se/amiga/hard/guide/A2090.guide)

Hope it works out for ya (if it doesn't, consider picking up a 2091 controller off eBay, they sell for peanuts there usually).
Title: Re: Problems with A2090a and a SCSI disk
Post by: patrik on February 05, 2004, 02:55:50 PM
*bumps the thread*

As the one who have been battling the A2090a together with fx I have to say some things.

1. We havent been able to find any concrete guide  covering how you actually install and prep a scsi drive using this card and the supplied software. This includes the A2090 guide posted in this thread.

2. Our main problem is that if we read the drive configuration from a drive using HDToolBox on another computer we get the following information:
- Cylinders
- Heads
- Blocks Per Track
- Blocks Per Cylinder

The MountList.HD file were we are supposed to define the the RES2: partition and supposedly DH2: partition (if anyone is curious about the wierd naming, check the A2090 guide link posted in the previous reply) we need to enter the following information:
- Low Cylinders
- High Cylinders
- Surfaces
- Blocks Per Track

So far so good, this mountlist can be edited to match the info supplied from HDToolBox assuming Surfaces = Heads.

The big problem comes after we have mounted RES2: and runs "prep RES2:" to prep the drive. We then have to enter the following information about the harddrive:
- Cylinders
- Heads
- Sectors Per Track

Using the information supplied from HDToolBox, the first two seems to be a breeze, but the Sectors Per Track?!

We have tried searching for information about the tested drives on the internet and tried all sorts of values we could find/think of. Disregarding what we try, the disk locks up (the access-led on the Quantum itself just stays lit) and nothing happens (yes, we have tried waiting for a looong time).

I anyone have any suggestions you are more than welcome! :)


/Patrik
Title: Re: Problems with A2090a and a SCSI disk
Post by: Jagabot on February 05, 2004, 06:24:51 PM
MFM / RLL were the only two types of drives you could buy "back in the day" (and your scsi is MFM I think).

The two values for MFM/RLL were 17 or 24.

That being said, I would have to guess the value you want to use is 17.

(This is all from memory). But I'm pretty sure the only two values you would ever enter in the Sectors Per Track field were 17 or 24.