• Updated 2023-07-12: Hello, Guest! Welcome back, and be sure to check out this follow-up post about our outage a week or so ago.

HD SC setup and 2GB and 4GB volumes/partitions

Realitystorm

Well-known member
Experimenting with a new SCSI2SD setup with a FAT32 formatted SD card containing volume files (similar to Andrew's exFAT version).
One thing I discovered as part of my experimentation was a couple of sizing quirks when I use HD SC setup:
  • HD SC setup automatically reduces 2GB volumes I tried to create from 2,097,152KB to 2,097,150KB, 2KB less.
  • HD SC setup has a maximum volume size of 4,151,534KB, 42,770KB less than the full 4GB (4,194,304KB) that is supported by 7.5.x+
  • HD SC setup has a maximum proDOS volume size of 32,767KB, NOT 32MB (32,768KB)
So for my new SCSI2SD FAT32 image I'm creating I have limited my volume/partition files to these sizes.
Not sure if there is any impact on what anyone else is doing with emulators or drive emulators, but I didn't see these quirks posted anywhere else.

I also added this information to my HFS entry on my site for my own future reference.

Summary of what I'm creating: a new "image" that can be written (raw-write) to a 32GB SD card that creates a 28.6GB FAT32 formatted partition on the SD card containing volume files that represent the HFS formatted volumes of 2 drives for your SCSI2SD to use (drive 1 with 6x2GB volumes + 2 proDOS, drive 2 with 4x4GB volumes + 2 proDOS). Hope to upload it this weekend once I finish some more testing.
 

MrFahrenheit

Well-known member
If you’re using the disk on a 68040 or greater Mac, volume sizes of more than 4GB are possible.

A third party formatting tool might serve the user better in that regard. I’m partial to FWB’s Hard Disk Toolkit (though specific versions should be mated with specific OS versions for best results), but I’m also fond of Silverlining and, lately, Software Architect’s Disk Drive Tool-Kit! version 3.14.

On my LC475, I have successfully formatted and used a 34GB drive, as well as a 100+GB drive on a Q800.
 

Realitystorm

Well-known member
I'm sticking with HD SC setup at the moment to support users of the Apple IIe card. I wasn't able to get my Apple IIe card's software to recognize ProDOS volumes created with other software. Although that was quite some time ago that I tried. I don't think I experimented with Software Architect's software.
 
Top