As described in my last post, I plan to divide up a 2 GB SD card like this:
|Partition Name||Description||Type||Sector Offset||Size (Sectors)||Size (Bytes)|
|SCSI2SD||Backup Utils||FAT||0||65,536||33,554,432 (32 MB)|
|Macintosh SD||SCSI 1||HFS||67,584||3,670,016||1,879,048,192 (1.75 GB)|
|Unallocated||–||3,737,600||184,320||94,371,840 (90 MB)|
|Total||3,921,920||2,008,023,040 (1.87 GB)|
Creating the FAT partition
The first step is to create the 32 MB partition at the start of the card. Usually SD cards come with an existing file system, so the first thing we need to do is remove it. On Windows 10 you can launch the Disk Management control panel by bringing up the Start menu, typing “disk management” and selecting Create and format hard disk partitions.
On my PC, the card is mounting as the F: drive, and you can see it already has an existing FAT file system that spans the entire card. The first task is to delete that file system. This is as simple as right-clicking on that F: drive at the bottom of the window and selecting Delete Volume….
You’ll be prompted that this will delete everything – go ahead and click Yes. Afterwards it should look something like this:
Now we want to add our new 32 MB FAT file system. Right-click on the unallocated space for F:, select New Simple Volume…, then click Next >. Here’s where you’ll set the size to 32 MB:
After clicking Next > again, you’ll be prompted to pick the new drive letter. It’s annoying that you can’t keep using F: here, but don’t worry, you can change it later if you really want to. On my computer it picked K:. I just took a note of the new drive letter and clicked Next > again. Here’s where you’ll be prompted to pick the type of file system and give the volume a name.
As per my table above, I’ve picked FAT and set the label to “SCSI2SD”:
Click Next > and then Finish to create the new partition. Afterwards, Disk Management looked like this:
Perfect! I now have my 32 MB FAT partition and an approximate 1.84 GB of unallocated space for SCSI2SD to use. More importantly: I have the peace of mind that I can insert this card into any computer without risking an accidental format which corrupts my vintage mac data.
Configuring the SCSI2SD
The next step is to configure the SCSI2SD, which means we’re done with the Disk Management tool and can return the SD card to the SCSI2SD. Then we’ll need to go and download the latest scsi2sd-util6 and (if you’re out of date) the latest firmware file for your model.
There’s a quick start guide (at the link above) that details installing the PC driver, connecting your PC to the SCSI2SD via a USB cable, and flashing the latest firmware file. Once you’ve done all that, it’s time to use the scsi2sd-util6.exe tool to configure the SCSI2SD.
For my model SCSI2SD (a 2020 V6), installed in my SE/30, this is how I configure the General Settings tab:
Next it’s time to set up the virtual SCSI devices. I select the Device 1 tab and configure it accordingly:
Now, you might be asking, “Why am I setting up the 32 MB FAT partition” as a SCSI device? Will the classic mac be able to use it?
Unfortunately, no. While various vintage mac utilities will see that the device exists, they won’t be able to access any files on it. However, the SCSI2SD V6 has an interesting feature, where, when you plug it into your PC with the USB cable, it will try to expose the SCSI devices to the computer as USB drives. So by setting this virtual device up, the 32 MB FAT drive appears on my PC and files can be managed directly without having to to remove the card. It’s not strictly necessary, but it is a nice bonus perk.
Anyway, on to the Device 2 tab, where again I set the values according to the table above:
You’ll notice that I haven’t done anything to “spoof” a particular drive by modifying the values for Vendor, Product ID, etc. Other guides often recommend using particular settings here, so that you can use the official Apple tools to format the new drive. The official tools only support specific drive models, and so must be tricked into thinking that’s what’s connected.
However, after much painful experimentation, I’ve found that neither Apple HD SC Setup (for System 6) nor Drive Setup (for System 7) works properly for this, even if you trick it into running. The newly setup drive will report its capacity incorrectly and suffer from constant data corruption and loss. I tried many times and was never even able to install a fresh system onto it.
In the end, I found that the only working way to set up the mac drive was to use the 3rd-party formatting tool Lido, which has no restrictions on what drives it can format, and works flawlessly.
But I’m getting ahead of myself. After setting this all up, the next step is to save it to the device, by selecting File > Save to device. I’ve also found it prudent save a backup of this configuration to my PC by doing File > Save to file… and naming it scsi2sd.xml. After that you’re ready to (safely) eject and disconnect the USB cable. Now the SCSI2D is ready to be used on my SE/30.
Some finishing touches
But before we switch to the SE/30, I have a couple more “quality of life” tricks I’d like to share, revolving around the card’s little FAT partition. I’ve curiously described as for “Backup Utils” and that’s what I use it for: backing up copies of all PC-side files I used to set up the device.
So, reinserting the card back into my PC, my drive now looks something like this:
You can see copies of the scsi2sd-util6 tools, the latest firmware, the quick start guide PDF, and the configuration backup scsi2sd.xml we just created. But there’s also two other files: dd.exe and manage.cmd.
If you’re familiar with common Unix utilities, dd.exe is just dd for Windows. It’s a small but powerful utility for reading and writing directly to a drive by sectors, making it very useful tool for creating and restoring backups as disk images.
The other file, manage.cmd, is something I whipped up myself. It’s a small script which makes it easier to use dd.exe to backup and restore the SCSI2SD virtual devices as individual image files.
Launching it provides this menu:
This is part of the reason why I saved my SCSI2SD config as the file scsi2sd.xml. Manage.cmd reads this file to determine which sector ranges on the disk correspond to virtual devices. This is also why I explicitly added the FAT partition as a device in the SCSI2SD config – so this script would be able to see it.
Now typing “1” and pressing enter, the script will prompt me, for each virtual drive, where to save a backup disk image. Then it will invoke dd.exe with the proper arguments to save off the image files:
To restore those image files, it’s as simple as entering “2” at the menu, and you’ll be walked through the reverse – prompting for the image files you wish to write back to the SD card. It’s not the most sophisticated system, and still doesn’t give me direct access to files within those images, but it’s a little nicer than having to run dd.exe by hand.
Note: The manage.cmd script expects to be run from the actual SCSI2SD SD card, as it uses that location to determine which disk to read and write from. If you use it, make sure that you also keep a backup copy of your scsi2sd.xml file in a place other than the actual SD card.
Well, that’s it for this post. Stay tuned for Part IX, where we’ll get back onto the SE/30 and start setting up a working system!
Want to read from the beginning? Start at Part I.
P.S. My thoughts on how to plan, execute, and document setting up my SCSI2SD was largely influenced by these two blog posts: SCSI2SD: Using a SCSI2SD adapter to setup your 68k Macintosh and Apple IIe Card and SCSI2SD: How I have my SCSI2SD setup for my Apple IIe card in my LC 475. Enormous thanks to the folks at savagetaylor.com for all of their detailed posts on classic macs and the SCSI2SD.