A500 supra scsi interface

[clh333]

A500 (Rev. 5 board) has Supra 500 RAM expansion (2Mb) and external 20 Mb SCSI drive, Seagate ST125N and Seagate integrated controller. A feature of the Supra rig is that it is expandable to host other SCSI devices, through a 25 pin port on the external drive's case.

I have an IOMEGA ZIP drive, SCSI interface, that I have used with other machines. I want to use this drive as a place to copy the software titles that are on 3.5 DSDD disks. (The 20 Mb Seagate is almost full).

The Seagate is configured as, and defaults to, SCSI ID 0. In my (limited) experience controllers are usually at ID 7, but I don't know if this is the case here. I have attached the ZIP to the expansion port, but have not been successful having it recognized. The ZIP can be configured as ID 5 or 6, and can have termination enabled or disabled. I have tried all 4 permutations, with limited results. I have also tried removing the termination resistors from the Seagate, again without success.

In certain of these configurations the Amiga will not boot, so termination is obviously required. Supra software includes a "park" utility, and in certain configurations the utility will report parking two drives. Occasionally the ZIP will spin down and eject its disk.

This is promising, but when I use the Supra configuration utilities, Format and Edit, they only list the controller and HD0: as devices on the SCSI bus. I'm not sure what to do to resolve this issue, and the Supra documentation is sketchy on this topic.

I would be grateful for any suggestions. Thank you.

Charles Hudson
clh333

[thomas]

Maybe the utilities stumble across how the ZIP drive identifies itself. It could say it's a MO or something. And removable, too.

However, the configs which allow to eject a disk sound promising for further investigation.

Which OS version (Kickstart) does your Amiga have?

And do you have any means to get downloaded software to your Amiga? Any advise I can give you will probably need this.

[mark_k]

Do you have a SupraDrive 500 or SupraDrive 500XP?

Which version of the Supra auto-boot ROM do you have? You can check either by looking at the circuit board (there should be a label on the EPROM chip) or using the SupraChkRom utility. If you don't have the most recent (AMAB6 I think) that could be one reason why you're having trouble getting the Zip drive to work. Older ROMs' support for removable media drives may be poor or non-existent.

Regarding SCSI termination, from the board pics on amiga.resource.cx it looks like there's a terminating resistor pack next to the SCSI connector on the PCB, marked RP4 in the SupraDrive 500 board pic and RP5 in the 500XP pic. If the Supra controller is at the end of the SCSI chain make sure the resistor pack is installed. (It's missing in the amiga.resource.cx 500XP pic.)

Other than that, make sure termination on the Seagate drive is disabled (remove the resistor packs) and enable termination on the Zip drive. Termination power could be an issue. If neither the Supra controller nor the Seagate drive supply termination power to the SCSI bus, the chain won't be properly terminated. External Zip drives don't supply termination power.

So, here are some things I'd try:

- Power on the Zip drive and insert a disk before turning on your Amiga (or reset your Amiga after doing that). If your boot ROM doesn't support removable media properly, doing it that way could allow it to recognise the Zip disk.

- Disable your controller's boot ROM and instead boot from a floppy disk which has the latest Supra driver on it; the SupraBoot disk should work.

- Remove the Seagate drive so you have only the Zip connected to the Supra controller. Having a shorter SCSI chain should reduce any problems caused by improper termination. Boot from the floppy again and see whether the Zip is detected.

- If you have access to a third SCSI device which does supply termination power, put that in the SCSI chain.

[clh333]

Originally Posted by thomas

Which OS version (Kickstart) does your Amiga have?

And do you have any means to get downloaded software to your Amiga? Any advise I can give you will probably need this.

Thank you for your reply.

Kickstart ROM is 1.3; WB 34.x. I have an early version of CrossDos and an external drive which I am able to configure as "DI1:" Through this I am able to import Amiga software.

There are limitations to this approach: The software has to fit onto an IBM-formatted 3.5-inch DSDD (720k) disk. Since the Amiga DSDD has higher capacity, any .adf image has to be archived.

It took some gymnastics to find a usable version of ARC (eventually found a Linux utility) that would compress to a format that my Amiga utility could comprehend. A story in itself, perhaps another post.

Thanks again,

Charles Hudson
clh333

[clh333]

Originally Posted by mark_k

Do you have a SupraDrive 500 or SupraDrive 500XP?

Which version of the Supra auto-boot ROM do you have?

Thank you for your reply and for your suggestions.

The Supra unit is a Supra 500, not an XP, unfortunately. In retrospect it would have been smart to spring for more RAM and a bigger HD. The optional clock would have been a good idea, too, but there we are.

The Supra main board carries boot ROM (hand) labeled AMAB 3. If there is a later ROM image, I do not know where to find it. Is there a known resource?

RP4 looks like a termination resistor array (16 pins, right between the connector and the 5380 controller IC) but it is soldered to the main board. The Seagate drive has an integrated controller card "piggy-backed" to the drive chassis. On this board is the 3x8 resistor array.

Mounted above this is a second card to which the cable from the main board attaches. It distributes this input to the Seagate drive and also to the 25-pin external port.

My documentation does not include a pinout for either port. Seagate's manual for the ST125N identifies pin 26 of the drive's 50-pin internal connector as "Termination power". I assume therefore that termination is powered at both ends.

Again quoting Seagate: "The termination resistor packs must be present on devices at both ends of the SCSI bus. All other devices should have the termination resistors removed," and "If you are installing one drive, leave the resistor packs installed. If you are installing multiple drives, remove the resistor packs from all drives except the last drive connected to the end of the cable."

I am powering up the Supra drive, which has its own power supply, and the Iomega ZIP drive at the same time, before powering the Amiga, as Supra recommends. The ZIP drive has a disk in it, since I have read that it will not be mounted unless a disk is present, and the ZIP's power and data lights both illuminate on power-up. The data light flashes a few times before extinguishing, as though it is receiving bus communication. However, it does nothing more until shutdown when it will occasionally eject its disk upon issue of the "park" command.

I have tried setting the ZIP as unit 5 with and without termination, unit six with and without termination, both with the Seagate resistor packs in place and with them removed. It's possible that the ZIP drive needs and is not receiving termination power, but that's unlikely given the fact that it has communicated with Adaptec and SIIG SCSI controllers in the past.

It may be that the Supra boot ROM is the source of the trouble, but with no alternate ROM I can't test that. My two alternatives at this point are to replace the ST125N with a larger drive or try to bypass the Seagate and communicate only with the ZIP.

Given the procedure for initializing a new drive, I think I'll try the second approach first. Thank you once again for your assistance.

Charles Hudson
clh333

[Jope]

I can provide you with the AMAB6 ROM image in exchange for a dump of the AMAB3. :-)

[thomas]

Originally Posted by clh333

There are limitations to this approach: The software has to fit onto an IBM-formatted 3.5-inch DSDD (720k) disk. Since the Amiga DSDD has higher capacity, any .adf image has to be archived.

720K is fine. Real Amiga software does not come as ADF files. ADF is only made for emulators. Nobody even thought about ADF before UAE or Fellow appeared for the first time.

If you need disk images of your real Amiga disks, DMS is the way to go.

Regarding your ZIP drive, you could try this: http://thomas-rapp.homepage.t-online...oads/tsgui.lha

In order to unpack the archive you might need this, if you don't have it already: http://aminet.net/package/util/arc/LhA_e138
Copy lha_e138.run to Ram Disk and run it. After all files have been extracted, copy LhA to C:.

Now enter lha -xa x di1:tsgui.lha ram:

Run TSGUI and choose "select raw device" from the menu. Select the driver of your SCSI controller as device and check if the ZIP drive is recognised by the unit selector.

[mark_k]

Originally Posted by clh333

The Supra main board carries boot ROM (hand) labeled AMAB 3. If there is a later ROM image, I do not know where to find it. Is there a known resource?

Yes, The Zone here on EAB.

Download the file expansion_boot_roms.zip and unpack it. The Supra AMAB6 ROM image is in that archive. If you have the capability to burn an EPROM with that data to replace your AMAB3 it'll be worth trying.

You should be able to see whether updating the boot ROM will help, without needing to actually burn an EPROM. Download the SupraBoot 3.8b disk from amiga.resource.cx. Disable your boot ROM (you might need to physically remove it if there's no disable jumper on the board). Boot from the SupraBoot 3.8b disk. The disk-loaded driver on that is the same version as the AMAB6 ROM.

(By the way: if you're able to dump the data in AMAB3 EPROM that would be useful/helpful to see what differences there are between that and AMAB6. You can dump it by running a program on your Amiga, or read the chip using an EPROM programmer.)

Seagate's manual for the ST125N identifies pin 26 of the drive's 50-pin internal connector as "Termination power". I assume therefore that termination is powered at both ends.

Not necessarily, but without having the ST125N OEM manual it's hard to say whether the ST125N supplies termination power to the bus or not.

If you have a SCSI chain like Amiga <--> Seagate <--> Zip then you should remove the terminating resistor packs from the Seagate drive and enable termination on the Zip drive. The Zip drive unit setting shouldn't matter. (I recommend getting an external active terminator so you don't need to remove or reinstall resistor packs on the Seagate every time you change its position in the SCSI chain.)

One other thing: it could be that the "last target" flag is set in the RDB of the Seagate drive, which could cause the Supra boot ROM to ignore all higher IDs. Try leaving the Supra drive powered off and the Zip on when you power on the Amiga and see if it detects the Zip drive then.

[TjLaZer]

If you need the AMA B6 ROM on a chip, I can help! $14 shipped.

[Jope]

Please dump the amab3 in any case. :-)

[clh333]

Thank you all for your assistance!

I had tried to access the zone but was unsuccessful and thought it was because I was not authorized, as the error message suggested. Didn't realize I had to "join", but have corrected that. Greatly appreciate the guidance.

I take it .DMS is a "DiskMasher" file compression product. Again, unaware.

I will dump the AMAB 3 ROM contents but will need to find the tool to do so. Already used TRANSROM to dump my Kickstart ROM contents to disk, but don't think that can be redirected.

Don't have a PROM burner and have yet to burn my first EEPROM. However, I keep running up against this issue so maybe it's time to look into acquiring one. Any suggestions?

Regarding the SCSI controller: Although there is a controller chip on the Supra's main board, the Supra Edit and Format utility consistently identify the Seagate 125 as the dh0: controller. I will try thomas' suggestion of TSGUI first and then try mark_k's suggestion for leaving the Seagate unpowered. The Seagate drive housing has its own 120VAC supply however and I'm not sure what will happen if I leave it off. Obviously I will be booting from df0: as a consequence.

Thanks aqain to all who responded. I'm not very knowledgeable but willing to learn.
Charles Hudson
clh333

[mark_k]

Originally Posted by clh333

I take it .DMS is a "DiskMasher" file compression product. Again, unaware.

Yes, you can download it from http://de.aminet.net/aminet/util/arc/dms111.run

That's a self-extracting archive, so copy the file to a PC floppy disk then run it on your Amiga.

Originally Posted by clh333

I will dump the AMAB 3 ROM contents but will need to find the tool to do so. Already used TRANSROM to dump my Kickstart ROM contents to disk, but don't think that can be redirected.

There are several tools you can use. One is TrackDOS.

Run TrackDOS, click Memory to DOS and enter $E88000 $E98000 for Source Address, $E90000 $EA0000 for End Address. Enter a filename in the box below (df0:romdump.bin or whatever) then click OK. [That assumes your Supra board is the first board in the system, which it should be.]

[clh333]

Originally Posted by thomas

Run TSGUI and choose "select raw device" from the menu. Select the driver of your SCSI controller as device and check if the ZIP drive is recognised by the unit selector.

I obtained the software packages, ran / unarchived them and invoked TSGUI. In the raw mode, with the supradevice selected, unit selector only saw unit 0; there was no other unit listed. Unit 0 is of course the HD. In this mode I also got the error message "unable to determine the size of the disk", although the Supra disk and its parameters were visible in the main interface.

Thanks again,
-CH-

[clh333]

Originally Posted by mark_k

Try leaving the Supra drive powered off and the Zip on when you power on the Amiga and see if it detects the Zip drive then.

With the Supra interface plugged into the A500 but the cable to the drive housing unattached, the Amiga was unable to boot: Got to a gray screen and no farther. With the cable attached but power to the drive housing switched off the Amiga again was unable to boot: Got to a light blue / cyan screen and no farther. In both of these tests the ZIP drive was powered on and a WB 1.3 disk in df0: Normally the Amiga will boot from df0: in preference to the Supra drive if a disk is present in df0: at power-on.

It appears that the Supra's presence is disabling the Amiga's boot ROM. I'll look for the tools you suggested; so far I have downloaded but been unable to unpack the Supra .DSM files.

Thanks again,
-CH-

[Arnie]

If you already have TSGUI (as Thomas mentioned earlier) then you just need to download DMS and put the file dms in C:. In TSGUI choose the .dms file to write and put a blank floppy in DF0:. Click on 'file -> disk' and TSGUI will do the rest.

[mark_k]

Originally Posted by clh333

With the Supra interface plugged into the A500 but the cable to the drive housing unattached, the Amiga was unable to boot: Got to a gray screen and no farther. With the cable attached but power to the drive housing switched off the Amiga again was unable to boot: Got to a light blue / cyan screen and no farther. In both of these tests the ZIP drive was powered on and a WB 1.3 disk in df0: Normally the Amiga will boot from df0: in preference to the Supra drive if a disk is present in df0: at power-on.

It appears that the Supra's presence is disabling the Amiga's boot ROM. I'll look for the tools you suggested; so far I have downloaded but been unable to unpack the Supra .DSM files.

How long did you wait at the grey screen? The Supra boot ROM probably waits quite a long time checking for SCSI devices before it gives up. Try waiting at least a minute.

Once you have copied DMS to your Amiga and run dms111.run to extract the archive, copy DMS to RAM:. You can run it without any arguments to get usage info (type RAM:DMS and press return).

With the supraboot DMS file in RAM:, you'd put a blank floppy in DF0: then do
RAM:DMS WRITE RAM:SupraBoot38b.dms TO DF0:

[clh333]

Originally Posted by mark_k

How long did you wait at the grey screen? The Supra boot ROM probably waits quite a long time checking for SCSI devices before it gives up. Try waiting at least a minute.

With the cable attached but power to the disk off the Amiga does not boot. It goes to a cyan screen repeatedly and gets no further. Without the cable attached, of course, there is not path to the ZIP disk.

However, I was successful in obtaining the DMS111 software, transferring it to the Amiga and extracting it. Armed with this I was able to write the Version 3.8 Supra disk images to floppies and then to boot from the floppy disk.

Mirabile Dictu! Supra Boot started a CLI and advised "There appears to be a problem with the hard disk. Would you like to run Supra Tools?" I ran the tool and it immediately inventoried what was on the controller, finding not only device 0 but device 5, which it correctly identified as a ZIP disk. Noting that there did not appear to be a format on the disk it offered to use the default, to which I assented.

I did nothing further but exited to the CLI, which after a brief wait continued to load. At the workbench the Supra HD icon was present and the drives contents were accessible once more. Screen shots are attached.

I have the Seagate ST125N with its termination in place and termination enabled on the ZIP disk as well. Additionally there appears to be a resistor array on the main board. I don't think termination was the main problem.

It appears the problem was with the Supra Boot ROM v.3. I captured the contents of memory location $E88000 to $E90000 with the tool suggested and will upload the file to the "zone" as soon as I pick myself up off the floor. I think I dislocated my arm in the celebration.

It has taken me untold hours to reach this point and I could not have done so without the help of the EAB membership. My sincerest thanks to you all for your assistance.

Charles Hudson
clh333

[mark_k]

Glad to hear you're getting somewhere! You're currently "over-terminated" but it doesn't seem critical. (Good termination seems to be more important for longer SCSI chains.)

By the way, I might have made a mistake with the instructions for TrackDOS. Could you also use $E98000 and $EA0000 for the start and end addresses?

[clh333]

Originally Posted by mark_k

Glad to hear you're getting somewhere! You're currently "over-terminated" but it doesn't seem critical. (Good termination seems to be more important for longer SCSI chains.)

By the way, I might have made a mistake with the instructions for TrackDOS. Could you also use $E98000 and $EA0000 for the start and end addresses?

Both addresses extracted and put into archive SBROM3.lha, uploaded to zone today 12:25 EDT.

-CH-

[mark_k]

Thanks for doing that. Unfortunately I screwed up for a second time in telling you what address range to dump!

Could you try again, but this time with start address $E90000 and end $E98000?