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bushok

Macintosh Plus won't boot from rare HDD

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Hi,

 

I've got a Macintosh Plus and I want to hook it up with a SEAD80 hard disk drive. I think this drive is quite rare. This drive is manufactured by SEA Software Nederland (the Netherlands) in 1990. It probably has 80MB storage capacity and I got it some time ago with an Apple IIGS.

 

I never got it to work with the IIGS, but probably the system on the drive is not suitable for my Plus.

 

Question: my SEAD80 drive has got 2 SCSI ports (IN and OUT [Dutch: UIT]). I think I'll need to use OUT when connecting to the Plus right? When I do so, I have the hard drive boot first before starting up the Plus. When I switch on the Plus, on the screen of the Plus appear big fat white and black vertical lines and it does nothing...

 

What can I do to make this combination working?

 

Greetings,

 

Rob

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Two questions: Does the Plus work normally without the drive? Does the Plus, if it works otherwise, work with any other SCSI equipment properly?

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It does work normally when booting from the floppy drive. I have never used a SCSI device before on the Plus (and don’t have any other then this) so I am not 100% sure this port is ok. 

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Remember SCSI does require termination. My guess would be your cable goes into "IN", and a terminator would need to be plugged into "OUT". Some drives had internal termination (my ProAPP20S does, for example).

 

It's also possible that given the Plus's wonky implementation of SCSI, you might want to try an Apple spec cable (these can be found on eBay).

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I’ve never seen SCSI terminators for these old SCSI connectors (I know about the 80 pin terminators), do they exist?

 

The cable is not Apple SCSI, true. 

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There are 50 pin terminators out there although the Centronix D-sub style terminator is a LOT more common.

 

I'm also curious if your drive/drive enclosure has termination circuitry built into it and if so, is it enabled?

 

I feel like this could also be a simple matter of assigning the drive a different SCSI ID.

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I would think the other way: you should terminate the IN port, and send the OUT port to the Plus. At the same time, with no other hardware to try, you cannot rule out some sort of SCSI port/chip problem on the inside. The only other thing I would think of is trying the drive with another Mac, if available.

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Yes, see what it produces on the IIfx. If it makes that machine hang up on starting, then I would suspect something with the drive. If it works fine, look at the Plus. I'm interested to see your results.

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Well the drive probably has ProDOS installed as I got it with a IIGS. So that will not work in the IIfx. I will test things tomorrow and let you know

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No, but if you are able to start the IIfx up with it connected at least, that would make me think that it would not be causing issues with the Mac Plus SCSI system.

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What about booting from floppy, and then turning on the drive? Assuming it boots, the Mac won't see it, but you might be able to reformat it. Dead McAfee Scrolls suggests this, and using Silverlining 5 to reformat it...

 

Edited to add: Remember the Plus doesn't provide termination power, so if your drive doesn't provide it, you'll need to add it in the SCSI chain. You can find pass through SCSI terminators easily enough on eBay. If I recall, you pug the DB25 into the Plus, the 50 pin into the passthrough, and the passthrough to the drive. Also, if the drive has a selectable SCSI id, try 5 or 6 (I think the Plus reserves 0 for itself).

Edited by Gsbtom

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15 minutes ago, Gsbtom said:

What about booting from floppy, and then turning on the drive? Assuming it boots, the Mac won't see it, but you might be able to reformat it.

This probably won't work. If the drive isn't powered on and responding to SCSI commands at boot time, then the Operating System won't add the drive to the Drive Queue.

 

You were always supposed to power on all SCSI devices before powering on the Macintosh.

Edited by Dog Cow

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1 hour ago, bushok said:

The cable is not Apple SCSI, true. 

You just identified the problem.

 

It's your cabling. Check the pinouts, as this hard drive and your cable for it are very likely using a different pinout than Apple's SCSI configuration (which by the way was non-standard), which is why your Mac Plus won't boot.

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4 minutes ago, Dog Cow said:

This probably won't work. If the drive isn't powered on and responding to SCSI commands at boot time, then the Operating System won't add the drive to the Drive Queue.

 

You were always supposed to power on all SCSI devices before powering on the Macintosh.

To be fair, I pulled this suggestion from Dead Mac Scrolls, but it might make sense here. The drive is likely formatted for the IIgs, and the Plus can't read it, and therefore chokes on it.

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I picked up one on eBay from blairdus, reasonably priced. It isn’t apple branded, but listed as supporting the Plus, and it does in my case.

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I would open up the case, remove the drive and try it in your IIfx.  If you open up the case, take a picture of the hard disk inside.

 

It's possible the power supply in the external hard drive case isn't working - You could test for 5V and 12V with the drive turned on.  Even with a SCSI cable issue, termination etc., I'm not sure why you would get those weird bars on the Mac.

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I've got some more clarity:

 

1. I found out that the Mac Plus also gives the fat white and black stripes when the SEAD80 drive is NOT turned on, but when the SCSI DB25-cable (non Apple) is in the back of the Plus. So @Gsbtom was right, it is the cable that is not ok for the Plus. Unfortunately I do not have an original Apple DB25 cable. I also do not have DB25 terminator, that could be a problem too.

 

2. @LaPorta hooked the SEAD80 up with my IIfx, with the DB25 (non Apple) SCSI cable I've got. The IIfx recognises the SEAD80, but won't mount it (see first pic). I've tried to reach the drive with Apple HD SC Setup (I think it is version 2.03), but that won't do it either (see second pic). Probably because I do not have termination?

 

3. @superjer2000 There is no power problem with the SEAD80. I can also hear it boot. While trying to mount it on the IIfx I found out that the hard drive is a Seagate 296N (it is also on the sticker). Here are the specs: https://stason.org/TULARC/pc/hard-drives-hdd/seagate/ST296N-85MB-5-25-HH-SCSI1-SE.html
I also posted some pics of the internals

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Oh it was @Dog Cow actually about the cables and pins. Does a SCSi DB25 cable for the Plus have less pins? Do you have a picture for me that shows it?

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The volume/partition map and/or drivers on the disk itself could be corrupted. I'd try Lido or other similar utility to reformat (unless it is the hacked version, Apple HD SC Setup will not work). If it worked with the IIfx and not the Plus, it could also be an issue with the Plus itself still, despite the cable doing it without the drive attached, so you may have two problems (Plus SCSI and drive too).

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On March 13, 2019 at 4:27 AM, bushok said:

Does a SCSi DB25 cable for the Plus have less pins? Do you have a picture for me that shows it?

No, it has 25 pins on the Plus side, and 50 pins on the peripheral side. This cable was called the Apple SCSI System Cable. Find a pinout in Inside Macintosh, volume IV, or check this page: Macintosh Plus SCSI Pinouts

 

But of course this Apple cable won't work for your hard drive, because the hard drive also has a DB25 port. I don't think your hard drive was designed to be used with a Macintosh. Apple's guidelines for SCSI was to use a 50 pin Centronics connector on all peripherals.

 

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Edited by Dog Cow

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