Hello, I have a Macintosh 512k. It has a SCSI upgrade. It looks like a knock off of the Dove MacSnap SCSI upgrade card. I have an external drive. Unfortunately, I can't get the computer to recognize it. I have tried all of the system tools that I have. But when I try to locate the drive, I can't find it. I know the drive is working. I connected it to a drive using a SCSI DB-25 to 50 Pin cable. If anyone has any ides on what software to use so that I can recognize the drive that would be great. --- Post Merged, Jul 8, 2017 --- I finally got it to work. I formatted the external hardrive on my Macintosh Classic using disk tools. The Macintosh 512k, with upgrade card now recognizes the drive.