[cctalk] QIC tape drives and SUN computers

Let's talk about QIC-24 (Quarter-Inch Cartridge) recording format tape drives. I have an Archive Viper 2150S drive and a few Tandberg QIC 1000 / TDC4120's. I have a collection of tapes that have had their elastic repaired to my satisfaction. I can see the tapes advance using the rewind command etc. Some of the tapes read fine and I can pull their data. My question is - a few of the tapes are not readable, I am using standard linux tape commands fed to the SCSI drive. I am wondering if Sun tapes are formatted differently and must be read in Sun tape drives. Could there be different types of physical BOT holes, or are they all the same? Is there something that makes a tape un-readable unless it's in a Sun/Windows/Linux/VMS environment? I am just trying to get the data, not use the data. At least not yet. My bench system is Linux Debian 7. I realize the tapes I have that I can't read may just be bad. Or maybe they're simply not formatted. I just don't want to give up until I am sure I have tried everything and know as much as possible. Any ideas? thanks Bill