One of the many challenges involved in digital preservation is accessing born-digital files on obsolete physical carriers such as Floppy Disks and Zip Disks. This requires action to ensure access and ongoing readability through migration to new storage mediums and/or file formats. As both software and hardware become obsolete, so do the mechanisms that enable us to transfer, render and view these files.
The Library recently acquired Apple Mac-formatted Floppy Disks that could not be read on our modern Digital Acquisitions PC or Apple MacBook Pro using a generic external USB floppy drive. There are two options available for dealing with this problem:
1. Purchase hardware designed specifically for disk imaging floppy disks, such as a Kryoflux, or
2. Purchase a vintage computer system to bridge the divide between old and new
These two options have advantages and disadvantages with cost and availability of components (both software and hardware) to support them.
Finding vintage computer systems can be difficult, particularly when you are looking for specific models. Research on accessing Mac-formatted Floppy Disks led to an informative blog post that recommends specific Macintosh systems with appropriate drives, can run particular operating systems and include a method to easily transfer data to a modern computer. One of the recommended systems, a PowerBook 1400c, was available on an online marketplace so we made the decision to purchase a legacy system and try our luck.
Released by Apple in 1996, the PowerBook 1400c has a swappable, module system for drives which enables the use of CD-ROM, Floppy Disk and Zip Disk drives. Provided the drives that were included with the computer worked, this would allow us to access these physical carriers using the one system. One drawback of the 1400c is that it does not have an Ethernet or USB port. As mentioned previously, it is important for legacy systems to be able to transfer data to a modern computer so this was another challenge that needed to be resolved.
We were excited when the computer arrived and found to be in good condition, running Mac OS 9.1. We successfully tested both the CD-ROM and Floppy disk drives with non-collection material to ensure they worked before trying the real thing. Our digital preservation colleagues at Archives New Zealand kindly provided us with some Zip Disks to test the Zip Drive, but this unfortunately failed. We will now consider whether we should try and source a working one, repair the existing one or look at other options.
Now that we had a system capable of accessing files on our Mac-formatted Floppy Disks, the next step involved creating a disk image from each Floppy Disk to ensure we had a forensic copy of its content. Mac OS 9.1 has a built-in program called Disk Copy which can handle disks up to 2GB. We successfully managed to image 7 disks, ensuring that they were write-protected using the write-protect notch on the disks. Not all were a success; a further 2 disks had partial failures where we could only “drag and drop” some of the files onto the computer and 1 could not be read at all.
Now the challenge was transferring these disk images to modern computers so we could extract and analyse the files. While the PowerBook 1400c does not have USB or Ethernet built-in, it does have two 16-bit PCMCIA (PC Card) slots that allow adaptors to be connected. The challenge here is finding both the PC Card and the appropriate software (drivers) for the operating system. Further research led to the discovery and purchase of a CompactFlash (CF) Card adapter that does not require any drivers. A Library staff member kindly donated an old 2GB CF card and we could easily transfer the disk image files to a modern computer.
After extracting the files from the disk images on an Apple MacBook Pro, we needed to analyse them to determine what they were as they had no file extensions. Utilising the open source program DROID (Digital Record Object Identification), we ascertained that the files were Microsoft Word for Macintosh format. Unable to open these files in the latest version of Word, we found that the open source equivalent, LibreOffice, was capable of both opening the files and migrating them to either PDF or DOCX to ensure they could be rendered and viewed on modern computers and software.
This complex process demonstrates the intricacies involved in accessing files on legacy, obsolete physical carriers and highlights the need to be proactive when it comes to our digital content. Transferring files off these carriers is only the first step in digital preservation where managing these assets over time requires ongoing validation, maintenance and migration to ensure they can be used in the future.
Words and photography by Matthew Burgess