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Amiga 2090A Questions

falter

falter

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Joined
Jan 22, 2011
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Vancouver, BC
Hi guys,

I have a 2090A controller that came years ago with my Amiga 2000. It has been installed in the Amiga since I had it but unused until now. I have no idea on functionality, but I was thinking of installing a SCSI hard drive to see if I can get that working. I don't have the install disks though, but have seen those online.. just wondering which I need ('Reinstall disk' 'install disk'?). And if there are any quick tips on how to determine if the controller is even alive.

Thanks muchly!
 
Software can be found here: http://amiga.resource.cx/exp/a2090a

The Amiga uses something called an "autoboot" ROM that provides driver support for the card in Workbench. You don't need the software to mount the drives normally. Given how limited this card appears to be (partition limits, etc.), you may want to seek out the newer A2091 SCSI card. It is very easy to find used and allows 2MB of extra Fast RAM to be added. It is also supported by all Workbench partitioning software since it supports Rigid Disk Block.

http://amiga.resource.cx/exp/a2091
 
Thanks muchly. I'm just using it because its what i have on hand.. just want to try it out.

Im assuming a .dms image is written the same way as an adf?


njroadfan said:
Software can be found here: http://amiga.resource.cx/exp/a2090a

The Amiga uses something called an "autoboot" ROM that provides driver support for the card in Workbench. You don't need the software to mount the drives normally. Given how limited this card appears to be (partition limits, etc.), you may want to seek out the newer A2091 SCSI card. It is very easy to find used and allows 2MB of extra Fast RAM to be added. It is also supported by all Workbench partitioning software since it supports Rigid Disk Block.

http://amiga.resource.cx/exp/a2091
Click to expand...
 
Okay so I made an attempt at it but not having any luck I don't think.

I run the Hard Disk install util, it runs through all the setup, and then I choose 0 for user defined drive (mine is a Quantum Prodrive LPS 105s). Now, I got confused when it asked for 'write precomp cylinder'. The only reference I could find to Precompensation on this sheet: http://stason.org/TULARC/pc/hard-drives-hdd/quantum/PRODRIVE-LPS-105-S-100MB-3-5-SL-SCSI2-SE.html had a value of 65535, which the Amiga will not accept.. the highest number it will accept is 1219. It did have a landzone of 1218, so I guessed and put that in. I then give it the OK to proceed, but it just sort of hangs there.. not sure if it's actually doing anything. Can't hear the drive working away or anything like that.

Thoughts?
 
Another thing I notice -- the hard disk indicator light is solid, all the time.. doesn't blink, etc.
 
I found my problem, I think. Turns out the battery corrosion that had damaged this Amiga had crept up into the A2090A card as well. Found some under the 8727 chip. Not sure how it got up there without touching the edge connectors first, but I'll try a vinegar/distilled water bath just for fun and see if I can revive it.
 
falter said:
Another thing I notice -- the hard disk indicator light is solid, all the time.. doesn't blink, etc.
Click to expand...

This may be "normal", depending on what you have plugged into the SCSI bus, and how the bus is terminated.
 
KC9UDX said:
This may be "normal", depending on what you have plugged into the SCSI bus, and how the bus is terminated.
Click to expand...

Yes actually.. it may be. I noticed the LEDs on the drive bodies stayed solid too. The card seems to be behaving a bit better with the cleaning I did.

I think I found my problem though.. apparently the a2090a only can handle scsi, not scsi2 drives. I had blithely assumed they were all compatible. Turns out not. Turns out even my oldest mac with internal scsi is scsi2. So that could be the problem right there. I can put in the specs and tell it to format.. but it just comes back with device not preped.
 
falter said:
I think I found my problem though.. apparently the a2090a only can handle scsi, not scsi2 drives.
Click to expand...
I don't recall having that problem, but then, I don't apparently recall much at all about this stuff anymore :(
I know there were several ROM revisions for the A2091, but can't remember about the A2090. If there are, perhaps a newer ROM would solve this.

Are you sure you're not having general SCSI problems? I have seen the controller LED stay on, but usually if one or more drive's LED stays on, that's a problem. Try terminating the bus on both ends and not plugging any drives in and see if the controller LED acts normal, that is, it should blink (very hard to see) whilst the controller scans for drives, on boot-up. If that works, add one drive and see what happens. Make sure to keep one terminator at each end of the chain until you determine for sure that won't work, in which case you'll have to do the "black magic" termination. Sometimes it's hard to tell if devices are terminated, and I don't remember if the A2090A has on-board terminating resistors.
 
A Quantum ProDrive of that vintage is SCSI-1 and shouldn't have any problems with that card. The ProDrive LPS was shipped with most early 90s Macintosh machines that were certainly 5MB/sec SCSI-1.The later SCSI-2 Quantum Fireballs were very picky and would refuse to work on SCSI cards that didn't have their own SCSI ID. I don't know if Commodore was in this group of cards. Does the hard drive work in another SCSI machine without a problem? They certainly weren't the most reliable units out there.
 
KC9UDX said:
I don't recall having that problem, but then, I don't apparently recall much at all about this stuff anymore :(
I know there were several ROM revisions for the A2091, but can't remember about the A2090. If there are, perhaps a newer ROM would solve this.

Are you sure you're not having general SCSI problems? I have seen the controller LED stay on, but usually if one or more drive's LED stays on, that's a problem. Try terminating the bus on both ends and not plugging any drives in and see if the controller LED acts normal, that is, it should blink (very hard to see) whilst the controller scans for drives, on boot-up. If that works, add one drive and see what happens. Make sure to keep one terminator at each end of the chain until you determine for sure that won't work, in which case you'll have to do the "black magic" termination. Sometimes it's hard to tell if devices are terminated, and I don't remember if the A2090A has on-board terminating resistors.
Click to expand...

As far as I can tell no general SCSI problems. I know for sure the drives work in the computers they're pulled from. Ive seldom had trouble with SCSI in the past. I wish I had an MFM drive ro try out. Only wwnt with SCSI because its what I have lying around.
 
njroadfan said:
A Quantum ProDrive of that vintage is SCSI-1 and shouldn't have any problems with that card. The ProDrive LPS was shipped with most early 90s Macintosh machines that were certainly 5MB/sec SCSI-1.The later SCSI-2 Quantum Fireballs were very picky and would refuse to work on SCSI cards that didn't have their own SCSI ID. I don't know if Commodore was in this group of cards. Does the hard drive work in another SCSI machine without a problem? They certainly weren't the most reliable units out there.
Click to expand...

All the drives from my Macs were LPS. One drive I pulled from a Mac Classic was an IBM DALS 3xxx and I looked it up and they have it as SCSI2 also. Think I am out of luck. Hard drives themselves are all known good. I'm stunned among all my old gear I don't have just a regular SCSI kicking around.
 
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