Hi all,
I am rebuilding the MagicSD thread because it was lost in the recent data loss event and I know that at least some of you found it useful.
What it is
It is an image that you write to an empty SD card and is meant to be used together with SCSI2SD. In contrast to other devices/projects such as MacSD (probably more) which are able to access files on a file system, SCSI2SD does not support this. Instead, it reads/writes data directly on the sd card by using a pointer (start sector on the sd card address space).
The problem with this operation principle is that the retro file systems are not exposed as files, and therefore it is not straight-forward to access them from a modern pc. Up until now one would need to copy (e.g. using dd) the data to a modern computer, alter the partition using an emulator and then dd the data back to the same location of an SD.
With MagicSD, the retro filesystems are accessible by both SCSI2SD and are also exposed by the underlying exfat file system, making it easy to transfer files (or alter contents of the retro partition) without the need to transfer the whole partition back and forth.
How it works
The files are carefully written sequentially on the exfat file system as normal files. SCSI2SD is given the start address of the data as this appears on the SD Card

Instructions
A) using an imaging utility (balena etcher, disc utility on mac os), burn the image on an SD card.
B) Set your scsi2sd device to use 10302 as the start sector, and use a device size of at least 1100mb (e.g. 2GB)
C) optional but recommended: Copy a mac plus rom file on the sd card. Then you can have a portable mini vmac installation running directly from the SD, auto-mounting the two partitions, and providing a fast and effortless way to transfer files.
You may add/remove files from the sd card, but it is important to not touch the 3 existing files (header.img, disk1.dsk, disk2.dsk)
Build from scratch
The provided solution is a proof-of-concept and is configured as 2x512mb partitions (for my mac plus this is all I need). The following steps are a high-level approach in order to build the solution from scratch in case you need to have more partitions or of a different size.
A) Use a real mac and a scsi2sd (or an emulator that supports scsi emulation) and apply your desired partition scheme.
B) Use dd to copy the scsi driver and partition table (first 48kb) to a file. Repeat for each partition you have created taking into account its size. You should now have as many files as your partitions +1. It might be a good idea to mount these in an emulator and verify they function correctly
C) Format an empty SD card on a modern PC. I used exfat but other file systems might also work correctly. Important: Select 1kb as the file system sector size.
D) Copy the files over to the SD card starting with the scsi driver and partition table file.
E) Using a hex editor, try to find the start sector of the 1st file (csi driver and partition table). Use this in scsi2sd
If you are successful in building your own partition scheme from scratch, please upload it here for other users to use.
I am rebuilding the MagicSD thread because it was lost in the recent data loss event and I know that at least some of you found it useful.
What it is
It is an image that you write to an empty SD card and is meant to be used together with SCSI2SD. In contrast to other devices/projects such as MacSD (probably more) which are able to access files on a file system, SCSI2SD does not support this. Instead, it reads/writes data directly on the sd card by using a pointer (start sector on the sd card address space).
The problem with this operation principle is that the retro file systems are not exposed as files, and therefore it is not straight-forward to access them from a modern pc. Up until now one would need to copy (e.g. using dd) the data to a modern computer, alter the partition using an emulator and then dd the data back to the same location of an SD.
With MagicSD, the retro filesystems are accessible by both SCSI2SD and are also exposed by the underlying exfat file system, making it easy to transfer files (or alter contents of the retro partition) without the need to transfer the whole partition back and forth.
How it works
The files are carefully written sequentially on the exfat file system as normal files. SCSI2SD is given the start address of the data as this appears on the SD Card

Instructions
A) using an imaging utility (balena etcher, disc utility on mac os), burn the image on an SD card.
B) Set your scsi2sd device to use 10302 as the start sector, and use a device size of at least 1100mb (e.g. 2GB)
C) optional but recommended: Copy a mac plus rom file on the sd card. Then you can have a portable mini vmac installation running directly from the SD, auto-mounting the two partitions, and providing a fast and effortless way to transfer files.
You may add/remove files from the sd card, but it is important to not touch the 3 existing files (header.img, disk1.dsk, disk2.dsk)
Build from scratch
The provided solution is a proof-of-concept and is configured as 2x512mb partitions (for my mac plus this is all I need). The following steps are a high-level approach in order to build the solution from scratch in case you need to have more partitions or of a different size.
A) Use a real mac and a scsi2sd (or an emulator that supports scsi emulation) and apply your desired partition scheme.
B) Use dd to copy the scsi driver and partition table (first 48kb) to a file. Repeat for each partition you have created taking into account its size. You should now have as many files as your partitions +1. It might be a good idea to mount these in an emulator and verify they function correctly
C) Format an empty SD card on a modern PC. I used exfat but other file systems might also work correctly. Important: Select 1kb as the file system sector size.
D) Copy the files over to the SD card starting with the scsi driver and partition table file.
E) Using a hex editor, try to find the start sector of the 1st file (csi driver and partition table). Use this in scsi2sd
If you are successful in building your own partition scheme from scratch, please upload it here for other users to use.
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