Amiga using Zip Drives
Welcome back to another installment of what can I do with my Amiga? Todays goal is to see if I can USB Zip drive to transfer data back and forth with my modern Mac.
Surly this can be done right? Right? Well lets head off for an adventure.
Systems being used
I will be using 2 of my Amiga's both running AmigaOS 3.2.2.1.
The first is an Amiga 4000T with an internal IDE Zip drive and the second is an Accelerated Amiga 2000 with a GVP SCSI card and external SCSI Zip Drive. This should cover a wide range of Amiga's out there.
Filesystems
The first challenge that is in front of us is that MacOS uses APFS (Apple File System) and the Amiga uses FFS (Fast File System). These two filesystems are not compatible with each other and while it would be an amazingly fun adventure to learn and explore writing a compatible filesystem for either of the machines that is sadly beyond my skill set at this time.
So what can we try to make this work? Is there a common filesystem that both systems can speak? Surprisingly there actually is one still in use that both can speak. The FAT (File Allocation Table) filesystem from the MS-DOS systems is still in use in some cases for modern systems and the Amiga has access to it as well. Lets see if we can make this work for us.
The modern MacOS is very easy as it is baked into Disk Utility. No problem formatting the Zip disk as FAT format.
The Amiga side took some experimentation to find a solution that would work. What was interesting is that I actually found 2 different device drivers that work.
The first is using CrossDos that is built into AmigaOS 3.2. This took the most experimenting and several other resources online to piece together something that worked. There where several posts on EAB that contained several great posts that helped a lot.
The second is using fat95 device that allows you to mount Win95/98 volumes as they are Amiga volumes. The install of this device was super easy and is amazingly tiny. I am really impressed with the work the author did and they even included the source code in the archive. There is a simple install_fat95 icon to click on that does the install for you.
Create mountlists
The Amiga is expandable by creating a mountlist that defines the drive, what device to use and with what parameters to use such as Sectors Size, Transfer rates, Dos Types, etc.
I am supplying 4 different mountlists 2 that I have successfully used on my A4000T and then 2 from the A2000.
To make a new mountlist it is fairly easy. Copy one of the other mountlists that is saved in your Storage/DOSDrives/devices folder to devs:DOSDrives/zip along with the .info file. Both the file and the .info file are needed here so be sure to copy both.
We will be editing the info file along with the file itself. The info file contains some parameters so we don't have to hardcode them in the text file itself.
Generally the Device and Unit number are defined in the device info file. This makes it pretty easy to change from the GUI and try different devices quickly.
I will have an example of using the .info file along with hardcoding the device in the mountlist itself. See the Amiga 4000T mountlists for an example of each. In the A2000 mountlists I will only use the .info files for the device and unit number.
From the workbench highlight the zip device you just created and goto Information about the device. Set Device=scsi.device where scsi.device is your actually scsi device. If you are using a GVP it maybe gvpscsi.device and other cards may use different device drivers. Set the Unit to match what you set your device for. Generally an external SCSI Zip drive will be set to 6. Be sure to check your device and set Unit=6 in that case.
Now edit the actually mountlist file and copy the appropriate example into yours replacing the previous contents.
Be aware in an Amiga 4000T the IDE ports actually show up a scsi.device unit 0 and unit 1 for Primary and Secondary IDE.
Replace the content of your zip mountlist with the contents of any of the 4 entries you want to try. I recommend using one of the A2000 entries.
Mountlist Amiga 4000T using fat95
Device = scsi.device
FileSystem = L:fat95
Unit = 0
Flags = 0
Surfaces = 1
BlocksPerTrack = 1
SectorsPerBlock = 1
SectorSize = 512
Reserved = 0
Interleave = 0
MaxTransfer = 0x10000000
Mask = 0x7FFFFFFE
LowCyl = 0
HighCyl = 196607
Buffers = 10
BufMemType = 0
BootPri = -127
StackSize = 8192
Priority = 10
DosType = 0x4d534800
Mount = 1
Activate = 1
GlobVec = -1
Reserved = 2
Mountlist Amiga 4000T using crossdos
FileSystem = L:CrossDOSFileSystem
Flags = 0
LowCyl = 0
HighCyl = 196576
Surfaces = 1
BlocksPerTrack = 1
BlockSize = 512
Buffers = 20
BufMemType = 1
BootPri = -127
StackSize = 8192
Priority = 10
GlobVec = -1
DosType = 0x46415401
MaxTransfer = 0xFFFE00
SectorSize = 512
Reserved = 2
Mountlist Amiga 2000 using crossdos
FileSystem = L:CrossDOSFileSystem
Flags = 0
LowCyl = 0
HighCyl = 196576
Surfaces = 1
BlocksPerTrack = 1
BlockSize = 512
Buffers = 20
BufMemType = 1
BootPri = -127
StackSize = 8192
Priority = 10
GlobVec = -1
DosType = 0x46415401
MaxTransfer = 0xFFFE00
SectorSize = 512
Reserved = 2
Mountlist Amiga 2000 using fat95
FileSystem = L:fat95
Flags = 0
LowCyl = 0
HighCyl = 196576
Surfaces = 1
BlocksPerTrack = 1
BlockSize = 512
Buffers = 20
BufMemType = 1
BootPri = -127
StackSize = 8192
Priority = 10
GlobVec = -1
DosType = 0x46415401
MaxTransfer = 0xFFFE00
SectorSize = 512
Reserved = 2
Be sure to save and wait a second before rebooting your computer for these entries to take effect.
When you insert a fat formatted disk it should now appear on your desktop.
If everything went well it is now party time!
Some Challenges
- Mountlist guesses
- Not sure how HighCyl plays in as you will see I have had 2 different values. I think fat95 driver seems a little more flexible.
- Title of the disk may be not as expected or look garbled but the data seems fine.
- I found this happens more with CrossDos than fat95
I hope you enjoyed this Amiga adventure with me and see you in the future for more.
