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My "New" Mac IIfx Sees My Seagate ST-225N as a "Large Volume That Cannot Be Used"

Concorde1993

Well-known member
I picked up another IIfx a couple of weeks back. Motherboard is in decent shape (all original caps) and it came with 20 megs of RAM.

Couple of things:
(1) The power switch in the back doesn't seem to work - more on that later
(2) The IIfx came with the HD carrier/sled for 5.25" drives, not the usual 3.5" - which is why I am using my trusty Seagate ST-225N in its 20SC enclosure running 6.0.8

Everytime I power up the IIfx, I'm greeted with this dialogue box at the desktop:
#1.jpg
Now I can access all of the contents on the ST-225N, and it seems to work perfectly fine considering its over 35+ years old. I never had this issue with it when I ran it with my Plus and SE, so I'm curious as to why the IIfx sees my 20MB ST-225N as a large volume that's over 4GB in storage. Is there anyway to fix this?

The other issue I'm having is the IIfx doesn't always shut down automatically, and I'm prompted to turn off the computer manually as I would a Compact Mac. The power switch doesn't seem to do anything - is this a sign of failing caps or a worn out power switch? My other IIfx never exhibited this problem.

Here's a pic of the Finder:
#2.jpg
 
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Phipli

Well-known member
I had a similar issue last week with a 9GB drive. All partitions were ~1.7GB but my IIci wouldn't mount them and Drive Setup claimed something was bigger than 4GB (same dialogue). The cause was I formatted the disk in too newer machine / mac combo (9.1 on an 8600) and I couldn't overwrite the driver properly for some reason.

I solved it like this :
I formatted the drive using the Mac OS 7.5.3 Drive Setup. This would make the partitions mount and the drive show in the patched version of Apple HD SC Setup (critically the latter would not see the drive otherwise!) until I next restarted.

I then manually used the Partitioning section of Apple HD SC Setup to delete all partitions and drivers from the disk. Everything. Gone. Yes, shouldn't reformatting do this? No, it didn't have the same impact - it retained a secondary driver and a patches partition for the drivers unless I manually deleted them.

Next I used the top level "Initialize" button on Apple HD SC Setup to format the drive - warning! This took at least 45 minutes to format and verify! Leave it!

Then I used the partition button to delete the new main partition (leave the driver alone!) and create the partitions I wanted (I recommend keeping them just under 2GB).

If I remember correctly, on quitting I was prompted to name the first partition. On Restart, I was prompted to name the rest.

Took me all day to get it right 😆 . Quirks of old computers.:rolleyes:

You can get the patched Apple HD SC Setup here : https://lowendmac.com/2007/format-any-hard-drive-for-older-macs-with-patched-apple-tools/
 

Phipli

Well-known member
(1) The power switch in the back doesn't seem to work - more on that later
Sorry, but this machine has trace damage in the power on / off circuit. Mostly in the back right of the board. It isn't in decent condition, and urgently needs a recap, repair and clean.
 

Concorde1993

Well-known member
Thanks for the info. I wouldn’t write-off this board though - sound is strong and all the other ports work as they should (NuBus slots included).
 

MrFahrenheit

Well-known member
I can’t recommend FWB Hard Disk Toolkit enough for formatting third party drives. Match its version up with the version of Mac OS you plan to run.

Make first partition only 10MB and make it not auto mount. Make second (boot) partition 1.9GB. Make other partitions whatever size you want. Works like a charm.

Also: recap at minimum the capacitor serving SCSI. Use a cap that is at least 25v at minimum. Apple underrated what they used and I’ve seen it myself twice blown.

Here’s the text from a post I made in 2020:

Boot from a disk that has System software on a 68k Mac. Use FWB Hard Disk Toolkit version 2.5 or 3.0.


Partition the drive as follows:

10MB Macintosh partition -set it to not auto mount. This is the partition that will hold your SCSI driver.


1.9GB (1900MB) Maximum second partition. Use it for your system folder.


1.9 GB third partition. This will show up as your second partition once booted.


Final partition for remaining size.


The SCSI manager on 68K Macs cannot handle drive sizes over 4GB without doing this, and cannot boot if the disk driver and system software are not contained in the first 2GB of the drive.


Here’s the text of a post I made about this on Reddit:

Pro Tip: Using large SCSI hard drives in old Macintosh machines (including Ultra 160 and Ultra 320)

I purchased a PowerMac 8600 that included a 4GB hard drive. The drive died. When I removed it I discovered a special adapter board and the drive was not 50 pin SCSI. The drive was actually a U160 drive with a SCA 80 to SCSI 50 pin adapter.


In the aftermath I discovered this whole new realm of SCSI. And the inexpensive large drives that are in it.

I found a lot of 4 Quantum Ultra 160 drives 18GB on eBay for $25 US including shipping. That’s about $7 a drive.

I tried to format one. I ended up killing it. Now down to 3.

Classic Mac OS is old. Dealing with drives this big requires special considerations. To save yourself some time, here’s a brief rundown of my experience on a 68040 Mac running System 7.6.1.

FWB Hard Disk Toolkit 3.0 is your friend here. The driver for the drive along with the first partition must exist in the first 2GB of the drive.

Easy solution: Use Autoformat to format the drive as a single volume. Then unmount. Set drive to not AutoMount and resize it to 10240 bytes (10MB). Create a 1.9GB or smaller partition for your OS. Then create another partition of the remaining drive space.

Boom! You can now boot older System 7 versions on a real SCSI drive on an 68k Mac with tons of GB of free drive space, using inexpensive decommissioned server drives.

YMMV regarding drive compatibility.
 
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joshc

Well-known member
Most IIfx with startup/shutdown issues are the boards with two electrolytic caps near the batteries/RAM slots. Those caps leak and damage traces in the soft power circuit. Thankfully the IIfx startup circuit schematic is available so repairing it is usually easy.
 

pezter22

Well-known member
The MacIIFX has the two Nand Gates for the startup/ shutdown circuits located near the RAM sockets on the edge of the board. They are UI18 (shutdown) and UJ18 (startup). There are two capacitors (C24 and C27) that usually leak and eat up the traces of the Nand Gates.
Here's a image of the MacIIFX startup circuit.
There is a great guide for the MacIIX (similar start up circuit) from Doug Brown that is very helpful with understanding how it works.
 

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ScutBoy

Well-known member
Most IIfx with startup/shutdown issues are the boards with two electrolytic caps near the batteries/RAM slots. Those caps leak and damage traces in the soft power circuit. Thankfully the IIfx startup circuit schematic is available so repairing it is usually easy.
This. My IIFX did the same thing until I replaced these caps and cleaned up the leakage in that area.
 

Concorde1993

Well-known member
Updating this as I transferred the data from the ST-225N to my 1.2GB Quantum drive that was partitioned using Silverlining 5.7

A few things:
(1) The ST-225N refused to be detected and initialized by the Silverlining 5.7 software (I would get either a system bomb or the Finder would hang indefinitely, prompting me to use the rear power switch on the IIfx, which works perfectly with my 1.2GB Quantum drive). I thought it was because the drive may have been too old to be reformatted with Silverlining
(2) I then attempted to reformat the ST-225N using Drive Utility in OS 8.1. The drive did not want to be initialized in low-level format, but it worked fine when I used the zeroing option
(3) I checked the drive for any errors using Drive Utility and Disk First Aid - no errors were found and the drive itself sounds healthy - but there's still an issue, which leads me to #4
(4) The ST-225N does not allow the IIfx to shutdown and restart after reformatting (I get a bomb if I attempt to use either). I then have to rely on the rear power switch to get the IIfx to switch off (and again this switch works perfectly with my other SCSI drives)

With all that said, I'm going to finally retire my venerable ST-225N. I've owned it for nearly 15 years but there appears to be a logic fault somewhere that is causing erratic behavior with my IIfx. I will say Apple really snugged in this beast into the 20SC enclosure. Does anyone have any tips on how to remove the ST-225N from the 20SC case safely? I'm not sure if I'll put in another 5.25" drive or go with a 3.5"
 

Concorde1993

Well-known member
So I removed the ST-225N from the 20SC case. It was fairly easy - even though the HD bracket is held in by those stupid plastic pressure tabs that always get brittle and break.

Fortunately, the bracket is interchangeable with both 3.5” and 5.25” drives. However, the 20SC seems to have been designed to only work with the ST-225N. There’s a 6-prong blue cable that controls the SCSI ID and is designed to plug into the back of the ST-225N. My 80MB Quantum ProDrive has a 6-prong port on the bottom where the logic board is seated, but I’m uncertain if that port is designed for controlling SCSI IDs. I could leave this cable unplugged but that would cause the 20SC to default to ID 0 all the time. The only possible workaround would be to change the SCSI ID of the IIfx’s main drive to something other than 0 in Silverlining 5.7 (if there’s a potential hazard in doing that let me know). Also the cable for the LED light is incompatible with the Quantum drive.
 

LaPorta

Well-known member
Maybe this isn't what you want to do at all, but why not pop a SCSI2SD internally in the HD spot and call it a day?
 

Concorde1993

Well-known member
But why not pop a SCSI2SD internally in the HD spot and call it a day?
Never really cared for that. I could reformat my 1.2GB Quantum drive and add another partition for 6.0.8 - but I'd like to know how to get the ID selector on the back of the 20SC to work with the jumper array of another drive besides the ST-225N. I had the same problem with my AVID SCSI case - it worked fine with my 9GB Seagate drive but the ID selector wire was not compatible with other drives.
 

robin-fo

Well-known member
I didn‘t read the full thread, so please excuse any duplicate.. But, IIRC, the IIfx needs a special black SCSI terminator. Did you use one?
 

Concorde1993

Well-known member
The black terminator thing is a myth IMHO. I’ve owned a IIfx for nearly 10 years and never had any issues using whatever terminators I’ve had on hand. Besides, this isn’t a termination issue - it’s now about getting another drive to interact with the SCSI ID cable in my 20SC since my ST-225N is screwed up.
 

Concorde1993

Well-known member
Installed Silverlining 5.7 on the 80MB Quantum drive. I can now control and set the SCSI ID through software - no need to worry about the ID selector on the back of the 20SC.

This HD shuts down and restarts the IIfx when prompted - not when it feels like it. Clearly something was goofed up with the logic circuitry on the ST-225N. Oh well.
 

ArmorAlley

Well-known member
The black terminator thing is a myth IMHO. I’ve owned a IIfx for nearly 10 years and never had any issues using whatever terminators I’ve had on hand. Besides, this isn’t a termination issue - it’s now about getting another drive to interact with the SCSI ID cable in my 20SC since my ST-225N is screwed up.
I think that black terminators are required for rev. A IIfxs.
Apple wouldn't have made if they weren't needed for something.
That being said, I haven't needed mine yet for IIfx.
I have it handy nonetheless.
 

MrFahrenheit

Well-known member
I think that black terminators are required for rev. A IIfxs.
Apple wouldn't have made if they weren't needed for something.
That being said, I haven't needed mine yet for IIfx.
I have it handy nonetheless.

I had seen a reply somewhere on the internet some time ago that active termination is better than the black terminators. If any terminators that you use are active, they would act like the black one, but even better.

Apparently all of the Apple-made gray terminators are active.
 

ArmorAlley

Well-known member
I had seen a reply somewhere on the internet some time ago that active termination is better than the black terminators. If any terminators that you use are active, they would act like the black one, but even better.

Apparently all of the Apple-made gray terminators are active.
I don't deny any of this. But Apple did make black terminators for the IIfx and distributed them with the IIfxs. They had a purpose then. Whether they still are the best tool for the job now is another question. I certainly haven't needed to use mine but then I either use built-in termination or active terminators.
 
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