There may have been Apple machines with ST-506s but unless my memory is much worse than I hope, there was never a Macintosh with an ST-506. Unless you're thinking of the "Macintosh Hard Disk 20"? But looking through old emails, that has a Rodime Model 552 drive inside with a mysterious 26 pin interface, not an ST-506. Outbound was a company. So they were producing non-Apple Macintoshes by scavenging Apple ROMs from Apple machines. The model number in this case is the Laptop Model 125. A very cool machine with four SIMM sockets devoted to a "silicon disk"--that is a dedicated RAM Disk. You could install up to 16MB in there--at least. I have not tried 16 MB SIMMs yet. The keyboard was detachable and had an IR interface. It also had a trackbar ("isopoint") at the bottom of the keyboard. A ?-bus (not PS2, not ADB that other one used on PCs (required an ISA card) with a round connector) mouse could be plugged into the keyboard if one preferred a mouse. Additionally, using the optional SCSI adapter, the Laptop could be "docked" as an accessible SCSI device on any Macintosh with a SCSI interface. The Laptop 125 was around as early as February 1990. I'm not certain exactly when it was first released. It pred-dates the Powerbooks. So, e.g. the cool SCSI docking feature was available on an Outbound, long before it was a feature on the PowerBooks. Jeff Walther