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Setting up SCSI2SD 4.2 for SE/30
Posted by: namsilat on 2020-03-05 16:55:48
Hi folks,

I just received my SCSI2SD 4.2 (the pocket version).  But I'm having some trouble getting it started.  I've downloaded and run the utility, with an SD card installed. And specified a 2GB disk on SCSI ID 0.  But it doesn't appear to be writing anything.   The software tells me that it's writing to the device. But when I quit the program, and unplug/replug the device into my MacBook, it doesn't show any volumes mounted.  Removing the SD card and mounting it normally through a car reader shows the entire 64gb journaled volume that the SD card had before I wrote the settings to the device.  Any tips?

Thanks!

Posted by: krishnadraws on 2020-03-05 17:02:53
I followed these steps on Savage Taylor and was able to get my SCSI2SD to work with my Mac SE FDHD. Good luck!

Posted by: LaPorta on 2020-03-06 05:42:30
I do not believe that any version of SCSI2SD mounts the card over USB except for v.6

Posted by: pcamen on 2020-03-06 08:55:14
I do not believe that any version of SCSI2SD mounts the card over USB except for v.6
Very true.  But I've never had issue with mounting volumes using the SD card directly as mentioned above. 

The software tells me that it's writing to the device. But when I quit the program, and unplug/replug the device into my MacBook, it doesn't show any volumes mounted.
This is as expected.  What you did is simply create a raw SCSI drive using the SCSI2SD utility.  You now need to partition and format using HD SC Setup (patched), Lido, or some utility so that it will have proper HFS volumes.  That is also why when you mount the SD card you still see the old volume; no new volumes have been written to the card. 

To put it another way, all you did was configure the SCSI2SD board to present a SCSI drive of a certain size, but you did nothing to setup the card / drive itself. 

Posted by: LaPorta on 2020-03-06 08:57:37
I thought the OP said that the card mounted fine when inserted in the reader?

Posted by: pcamen on 2020-03-06 09:10:18
I thought the OP said that the card mounted fine when inserted in the reader?
Yes, but it only mounted the original 64GB volume, not the 2GB volume he was expecting.  That's because no new volume has yet been written I surmise.  Unless I misread something. 

Posted by: cheesestraws on 2020-03-06 09:11:55
The point is that on the sd2scsi < v6, no actual information about volumes is written to the card.  The information is stored on the sd2scsi unit itself.  So setting up a new drive won't write anything to the SD card, so it will appear exactly as it did before.  To actually write to the SD card you'd need to write to the virtual scsi disc.  When it says 'writing to device', it means writing to the sd2scsi memory itself, I believe.  So this all sounds like expected behaviour to me...

Posted by: pcamen on 2020-03-06 09:16:23
The point is that on the sd2scsi < v6, no actual information about volumes is written to the card.  The information is stored on the sd2scsi unit itself. 
Does the v6 actually write the partition table too?  My understanding is that the only difference with the v6 is that it stores the SCSI2SD configuration the card instead of some flash memory on the SCSI2SD board, but the partition table and volumes are still written by the tools on the vintage Macs.  So if the OP did the same thing with a v6, they would have the same result. 

Posted by: cheesestraws on 2020-03-06 09:18:29
Does the v6 actually write the partition table too?  My understanding is that the only difference with the v6 is that it stores the SCSI2SD configuration the card instead of some flash memory on the SCSI2SD board, but the partition table and volumes are still written by the tools on the vintage Macs.  So if the OP did the same thing with a v6, they would have the same result. 
Yeah, v6 only stores the information about volumes on the card, it doesn't format them or anything - so chances are good that existing partitions would still function.  But I don't know where it stores it, so I didn't want to make any categorial statements about v6 🙂

Posted by: pcamen on 2020-03-06 09:23:21
One of my pet peeves about the SCSI2SD utility is that it is too easy to accidentally select save to device rather than load from device in the menu, meaning, if I want to first read the config from a device, inspect and modify it and then write it, more than one time I've accidentally written the config from some other device I had previously loaded as I accidentally released the mouse button on the wrong menu item. 

Luckily, it doesn't affect the volumes as we are discussing here, so it is easy (if you remember what it was) to set up the same config again for the device and write it back, without any data loss or other issues. 

Posted by: LaPorta on 2020-03-06 11:56:02
That’s what I was getting at: allocating the drives in the SCSI2SD utility does not create partitions or drives. If the card is already formatted, nothing will change. When connected to a SCSI Mac, the hardware makes the Mac think there is a 2 GB drive, and the hardware allocates bytes X through Y on the card as to where data should be read and written.

Posted by: Realitystorm on 2020-03-06 13:33:56
That’s what I was getting at: allocating the drives in the SCSI2SD utility does not create partitions or drives. If the card is already formatted, nothing will change. When connected to a SCSI Mac, the hardware makes the Mac think there is a 2 GB drive, and the hardware allocates bytes X through Y on the card as to where data should be read and written.
Yep, that's my understanding too.  The SCSI2SD utility doesn't write anything to the SD card.   There is bit of storage on the SCSI2SD adapter itself where settings are stored.  When you connect the SCSI2SD adapter to your computer it "tells" the computer it is the one or more drives that you've setup in the SCSI2SD utility, it is the computer's OS, thinking that it's talking to that/those actual hard drive(s) that does all the work.    The image files on my site provide a shortcut in the work by providing you a bit for bit copy of one of these emulated drives that you can copy on to the first part of you SD card (or other parts if you know what you're doing with DD http://www.savagetaylor.com/2019/12/19/how-ive-setup-the-scsi2sd-that-i-use-in-my-lc-475/)

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