How I’ve setup the SCSI2SD that I use in my LC 475

For reference by my future self, and for anyone that might want to duplicate my setup, I’ve documented how I’ve setup the 32GB SD card that I use with my LC 475:

  • SCSI 0 (device 1) is a 2GB drive with 3 partitions:
    • one 2GB HFS formatted drive
    • two 32MB ProDOS partitions to use with my Apple IIe Card.
  • SCSI 1 is a 26.5GB drive with 9 partitions:
    • one 2GB HFS formatted drive as my main working drive (with the OS)
    • six 4GB HFS formatted drives, mainly used for CDROM images.
    • two more 32MB ProDOS partitions.

1. Partition Details

I purposely create all my drives and drive partitions to be multiples of 1MB (1,048,576‬ bytes) with start and end positions also at multiples of 1MB so I can more easily backup my SD card, then extract and edit my drive partitions using dd (see sections 3, 4 and 5). For information on dd, see section 3 of my blog entry: Setting up your vintage (classic) 68k Macintosh – Creating a bootable hard drive starting with a image file and an emulator

SCSIPartitionFormatBlocksBlock sizeSeek/Skip
01 (Mac.OS)HFS20305921KB 48
02ProDOS32767 1KB2030640
0Total Size20481MB
0SCSI2SDcount4194304512 bytes
1SCSI2SDstart4198304512 bytes
11HFS 40601MB2050
12HFS 40601MB 6110
16HFS 40601MB22350
18ProDOS 32767 1KB29317120
19ProDOS32767 1KB29349887
1Total Size266451MB29383632
1SCSI2SDcount54568960512 bytes
1SCSI2SDend58767264512 bytes
Bothtotal (dd)287001MB
Figure 1: SCSI2SD settings for Device 1 / SCSI 0
Figure 2: Partition Information for for Device 1 / SCSI 0 (The Apple.II.D1 and Apple.II.D2 were later renamed D3 and D4)
Figure 3: SCSI2SD settings for Device 2 / SCSI 1
Figure 4: Partition Information for for Device 2 / SCSI 1
Figure 5: My Mac LC 475 desktop

2. Summary of my steps for creating my “drives”

  1. I used DD to create a 2GB file for device 1 (SCSI 0): dd if=/dev/zero of=my.img bs=1M count=2048, and tool that can make empty binary files can be used.
  2. I initialized the 2GB file as a drive image containing the 3 partitions described in section 1 above, using SoftMac. You could also use PCE or MAME could also be used. (Figure 1)
  3. I installed the full version of system 7.5.5 on to the Mac.OS partition of the 2GB image.
  4. I copied over all the other applications and files that I include on my standard images.
  5. I wrote my 2GB image to my 32GB SD card
  6. I inserted the 32GB SD card in to my SCSI2SD adaptor
  7. I setup my SCSI2SD adaptor with 2 drives
  8. I connected the SCSI2SD adaptor as the internal drive in my LC 475
  9. I booted the LC 475
  10. I used my patched version of HD SC Setup  to initialize my drive 1 in to 9 partitions…. I haven’t found an emulator yet that can handle drive images larger than 4GB, except MAME which was way to slow, this is the reason why I create a 2GB drive 1 and a larger drive 2.
  11. I copied some test files to each partition
  12. I shutdown my LC 475
  13. I took out the 32GB SD card out of the SCSI2SD adaptor
  14. I used dd to copy the portion of my 32GB SD card that contains the two drives, the result is a 28,700 MB file. (see section 3. below)
  15. I make a backup copy of the file from step 14 (in case something goes wrong with my edits)
  16. I used dd and a batch file to extract the seven 4GB HFS partitions from drive 2 as seven partition images. (see section 4. below)
  17. I used Basilisk II with the seven partition images from step 16 and the bootable image from step 4 to copy the Toast/ISO images from several games on to those partitions so I can mount the images without burning CDs πŸ™‚
  18. I used dd and a batch file to write the 7 HFS partitions back to the 28,700 MB, I created in step 14. (see section 5. below)
  19. I wrote the 28,700 MB file back to a 32GB SD card
  20. I inserted the 32GB SD card back in to my LC 475
  21. I finish organizing everything how I want.
  22. I repeat steps 12 to 15 so I have a up to date backup with everything organized exactly how I want.

3. Backing up the SD Card

One of the best things about using a SCSI2SD adapter is how easy it is to backup your 68k Macintosh’s entire drive.

  1. Remove the 32GB card from my SCSI2SD adapter
  2. Insert the SD card in to my USB adapter / reader for my PC
  3. open the terminal / command line window
  4. Type dd --list (windows), diskutil list (linux and mac OS) and press return
  5. You should see a list of all attached drives for your system with their names, you should see the name or your micro SD, SD or CF card, you want the identifier of the floppy drive eg.
    • for linux or mac OS something like /dev/disk2
    • for windows something like \\.\Volume{bc8eb0e4-a23d-11e8-9982-00e18c7bb83e}\
  6. Using the SD card as the input file, create a backup file: β€œdd if=INPUTFILE of=OUTPUTFILE bs=BLOCKSIZE count=BLOCKCOUNT ”:
    • INPUTFILE = {identifier from step 5}, e.g. /dev/disk2 or \\.\Volume{GUID}
    • OUTPUTFILE =  the location and name of the image you would like to create.
    • BLOCKSIZE, this is why I created my drive to be in multiples of 1M, so I could use a 1M blocksize.
    • BLOCKCOUNT, the number of blocks to read from the card. I’ve set up my 32GB card (actual 29.7GB) so that only the first 28700 blocks are used (includes SCSI 0 and SCSI 1)
    • e.g:
      • linux or mac OS type β€œsudo dd if=/dev/disk2 of=LC475_backup.dsk bs=1M count=28700
      • for windows type β€œdd if=\\.\Volume{bc8eb0e4-a23d-11e8-9982-00e18c7bb83e} of=LC475_backup.dsk bs=1M count=28700 --progress”
  7. press return
  8. wait….

4. Editing a “partition”

I can also extract each partition as a separate file that you can them mount in Basilisk II as a “drive”:

dd if=d:\LC475.img of=d:\s0p1.img bs=49152 skip=1 count=42304 --progress
dd if=d:\LC475.img of=d:\s1p1.img bs=1M skip=2050 count=4060 --progress
dd if=d:\LC475.img of=d:\s1p2.img bs=1M skip=6110 count=4060 --progress
dd if=d:\LC475.img of=d:\s1p3.img bs=1M skip=10170 count=4060 --progress
dd if=d:\LC475.img of=d:\s1p4.img bs=1M skip=14230 count=4060 --progress
dd if=d:\LC475.img of=d:\s1p5.img bs=1M skip=18290 count=4060 --progress
dd if=d:\LC475.img of=d:\s1p6.img bs=1M skip=22350 count=4060 --progress
dd if=d:\LC475.img of=d:\s1p7.img bs=1M skip=26410 count=2220 --progress
Figure 6: Basilisk II settings with each partition added as a drive
Figure 7: Basilisk II with the mounted partitions (note I did not include the ProDOS partitions, but I could if I wanted)

5. Writing Edited Partitions back to your SD Card

Once I’ve finished making my changes and getting everything setup the way I want using Basilisk II, I write back the partition files to the file I created way back in section 2 step 6, then write that file back to an SD card:

I typically alternate between 2 different 32GB cards, that way if anything “fails” during the write process I have a the card I originally read from in section 2 as a backup.

dd of=d:\LC475.img if=d:\s0p1.img bs=49152 seek=1 conv=notrunc --progress
dd of=d:\LC475.img if=d:\s1p1.img bs=1M seek=2050 conv=notrunc --progress 
dd of=d:\LC475.img if=d:\s1p2.img bs=1M seek=6110 conv=notrunc --progress 
dd of=d:\LC475.img if=d:\s1p3.img bs=1M seek=10170 conv=notrunc --progress 
dd of=d:\LC475.img if=d:\s1p4.img bs=1M seek=14230 conv=notrunc --progress 
dd of=d:\LC475.img if=d:\s1p5.img bs=1M seek=18290 conv=notrunc --progress 
dd of=d:\LC475.img if=d:\s1p6.img bs=1M seek=22350 conv=notrunc --progress 
dd of=d:\LC475.img if=d:\s1p7.img bs=1M seek=26410 conv=notrunc --progress

Once the combined file is updated I write it back to my SD Card, typically using balenaEtcher.

2 thoughts on “How I’ve setup the SCSI2SD that I use in my LC 475

  1. Pingback: Paul Weinstein

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