I'm attempting to use the SCSI2SD v5 with a 128G microSD card.
You can find out the size of an SD card attached to a modern Mac with
diskutil list and then
diskutil info /dev/disk8 (or whatever device it's listed as). This microSD card is reported as:
# diskutil info /dev/disk8 Device Identifier: disk8 Device Node: /dev/disk8 Whole: Yes Part of Whole: disk8 Device / Media Name: SD USB_3_0 Read Volume Name: Not applicable (no file system) Mounted: Not applicable (no file system) File System: None Content (IOContent): None OS Can Be Installed: No Media Type: Generic Protocol: USB SMART Status: Not Supported Total Size: 127.1 GB (127103139840 Bytes) (exactly 248248320 512-Byte-Units) Volume Free Space: Not applicable (no file system) Device Block Size: 512 Bytes Read-Only Media: No Read-Only Volume: Not applicable (no file system) Device Location: External Removable Media: Yes Media Removal: Software-Activated Virtual: No OS 9 Drivers: No Low Level Format: Not supported
So, the microSD has 248,248,320 sectors.
An ISO of the Genera 8.3 CD is about 636,682,240 bytes long, or 310,880 CD-ROM sectors of 2,048 bytes each or 1,243,520 SD card sectors.
I'll put the CD-ROM, for testing purposes, at sector 240,000,000. This can be done with
dd if=GENERA_8_3.iso of=/dev/disk8 seek=240000000.
Now, I configured SCSI2SD with:
- Original XL1201 Partition
- Copied from original SD, 10,311,338 blocks of 1,280 bytes each = 13,198,512,640 bytes or about 12.3GB
- SCSI ID: 1
- Hard Drive
- SD card start sector: 0
- Sector size & count: as above
- (Next SD start sector is 25,778,345 because SD sectors are 512 bytes)
- Genera 8.3 CD-ROM
- SCSI ID: 6
- SD card start sector: 240,000,000
- Sector count: 310,880
Earlier, I had modified the
*.boot files to use
FEP8: so this will boot fine.
And, lo and behold, it works!
So, apparently it's perfectly fine to use SCSI2SD with 128G microSD cards.