Atari and external SCSI

[clh333]

I wanted to be able to move software between the PCs, which have Internet access, and the Ataris, which do not. For other machines I am able to do this by means of an Iomega Zip drive using a SCSI interface. For that reason I purchased a SUPRA SCSI interface which is pictured below.

I have done what research I could to find documentation - so far unsuccessful. I can figure out some of the ports on the board: the 19-pin D-SUB (J3) is pretty obvious, as is the 50-pin header (P1) at the opposite end. Header J1 is obviously power, but what voltage? Header P2 (26 pin) and jumper header JP1: no idea.

Before I connect anything to it I thought I would ask for help here. Any suggestions or documentation is welcome.

Thanks,
-CH-

Pic:

SUPRA_SCSI_ATARI_EXTERNAL.jpg

[siriushardware]

I don't see a 5V regulator on that PCB, so:

If you have a meter, measure for a short between the + pin on the power connector and (as seen in your picture) the upper left pin (pin 20) on the 74HCT245 IC next to it. There should also be a short between the - pin on the power connector and the lower right pin (pin 10) on the same IC. If these pins aren't connected to the power connector pins as I have described could you please post an equally good picture of the underside of the PCB.

If you do have a direct connection between the + power pin and pin 20 of the IC then you almost certainly need regulated 5VDC going into that power connector. The SCSI drive will need both +5V and +12V (and 0V) supplies, so maybe an old PC PSU would be a good starting point. You can power the drive from that using one of the drive connectors already fitted to the PSU and take the 5V supply needed for the board from one of the other power connectors (e.g. red / black on one of the floppy drive power connectors).

The use of the same colour wire (blue) for both sides of the power connection is just asking for trouble. I would change those to red and black if possible. If not, sooner or later you will be lured into connecting them the wrong way around.

[Atarieterno]

http://www.atari-forum.com/viewtopic.php?t=10419

[frank.lukas]

Does all Supra Harddrives and Hostadapter need special Supra Driver Software?

I think yes ...

[clh333]

Thanks to all who replied.

"If you have a meter, measure for a short between the + pin on the power connector and (as seen in your picture) the upper left pin (pin 20) on the 74HCT245 IC next to it. There should also be a short between the - pin on the power connector and the lower right pin (pin 10) on the same IC."

Measures 0.3 Ohms, and drops quickly to 0.0.

"viewtopic.php?t=10419"

I did see that topic before I posted. I have been chided in the past for digging up old threads so I thought it best not to add on to that one.

"Does all Supra Harddrives and Hostadapter need special Supra Driver Software?"

I suspect that is true. I also have recently acquired a Megafile 30, which I can communicate with but which I have not yet been able to make boot, and also a Supra external HD. The Supra came configured: I plugged it in and it self-booted. I believe there are drivers on the disk; they may suffice but I don't know yet.

I also have a Supra combination RAM expansion and HD "sidecar" for an Amiga 500, as well as the installation and driver disks for that. I don't know if that will be of any value either.

Attached is a pic of the back side of the board:

-CH-

SUPRA_SCSI_ATARI_EXTERNAL_BACK.jpg

[Atarieterno]

Hello;
I showed you the old post for two reasons: if it is useful for your question and to continue to fill in the information that can help others.
I do not understand what is wrong with "resurrecting" an old post if it can complete information instead of remaining stored with doubts; but I do not make the rules.
Greetings.

[clh333]

No offense taken; I simply am trying not to irritate the moderators.

-CH-

[siriushardware]

clh333, for what it is worth I think it is OK (and desirable) to continue all discussion about one particular narrow issue into one thread, even if the thread has been dormant for quite a while. If the old information is still directly relevant and useful then what's the problem? I would rather find and read one mega-thread on my chosen issue than hunt all over through many threads for small fragments of information.

Your underside view (another nice photo) doesn't show an onboard regulator either so I am 99% convinced that this board requires a regulated 5VDC supply going in on the power connector.

As I said, the most convenient source for the regulated 5V and the additional 12V supply that the HDD will need would be an old PC power supply, especially because the PC supply will already have some correct type power connectors to match the one on the HDD. On the four-wire power output connectors on those the colour coding is always

Black=0V / Ground,
Red = +5V
Yellow = +12V.

[clh333]

I agree; better to confine one topic to one thread.

On another site, and a different topic, I once was "flamed" for responding to an old post. The post gave a link to some software utility I had been looking for (a Google search for the software was what led me to the site). I left a message saying "Thanks for making this available; it was just what I was looking for." I was chided for "necro-posting" or something like that by someone who took exception. I could only respond, "I hope you feel better soon."

I've got several spare power supplies but lately I have been using the adapter rig shown below. I use it to power the drives I use to image disks with either the Kryoflux or SuperCard Pro hardware.

Thank you all for your suggestions.

-CH-

Pic:

PowerSupply2.jpg

[Rustynutt]

Think you can use ICD or HD Driver with the Supera controller.
I do have the original package, in luck, backing up some old CD's tonight.
Give me a bit, wife just said dinner is ready

[Rustynutt]

Pasta and meatballs

Zipped this on the TT with ST Zip 2.3. Windows opened it, but that's all I can say, other than some say the ST Zip is buggy (never had issues).

I'd also say it's 5V, that's what all those IC's are. Pretty sure SCSI term power is the same.

[clh333]

Thanks for the upload. Term power: good point. Possibly what JP1 is for?

-CH-

[wongck]

My 44MB Syquest came with a Supra ASCI-SCSI thingy and I have successfully used all the drivers I found on it.

[czietz]

Thanks for the upload. Term power: good point. Possibly what JP1 is for?

-CH-

Being next to the Real Time Clock (RTC) chip: possibly for a battery to keep the clock running? Follow the traces from the header.

[Rustynutt]

Clock seems right, when I mentioned term power, only it's 5v source used, not your connector.

[clh333]

I also have acquired a Supra Atari HD, which came with a 105 Mb Quantum SCSI drive that was already formatted and loaded with Supra's utilities, so that it would boot. One of the utilities was a clock-setting routine. When I ran it I came to the conclusion that the Supra unit must have a RTC itself, because there were three clocks shown (System Keyboard and Supra), all with the wrong time.

So I opened up the Supra drive to see what was the RTC, and I found the twin of the above board, this one all connected. Referring to the attached picture you can see that the 50-pin header is cabled to the drive, the 19-pin d-sub is for the expansion or second ACSI drive and the 26-pin header goes to the 25-pin d-sub on the case. J2, which is empty in the above board, has a right-angle header to which is affixed the Atari ACSI cable's input.

The RTC has a dead battery but that is solvable; Maxim replacements are still available and the chip can be (carefully) modified to fit a new external battery. The power supply visible below quite likely puts out +5VDC although I have yet to measure it and jumper JP1 is pinned the left- or forward-two pins connected. For this reason I do not believe JP1 is a battery input.

More investigation is necessary to figure out what pin on the SCSI out port mates with what pin on the 26-pin header, and to verify voltage, but ZI thought I would post these findings now anyway. More to come.

-CH-

Pic:

SupraAtariSCSIHDController2.jpg