Back in the mid-90s I used a Quadra 840AV with an external SCSI MO drive (exact model/SCSI ID long forgotten) running Mac OS (Kanji Talk) 7.x. I recently recovered a stack of old 128MB MO disks (ISO/IEC 10090 standard, 512B/sector) written from that same Quadra 840AV setup — a mix of Sony-brand and KAO-brand media, stored together in identical conditions (climate-controlled, low humidity) ever since.
Testing them now on a PowerBook G4 Titanium (Mac OS 9.2) with a Buffalo USB MO drive (MO-CU2):
Sony-brand disks: mount and read fine
KAO-brand disks (10+ disks, same era/setup): fail identically every time — drive spins up (audible), but the LED never blinks (no seek activity), and the disk ejects automatically after ~10 seconds. No retry clicking sound.
I also tested both on a Windows 11 PC with a different Buffalo USB MO drive (MO-CM640U2):
Sony disks: drive icon appears clearly, Windows reports "disk not readable" (expected, since it's HFS-formatted)
KAO disks: drive icon appears only faintly/intermittently, then ejects after a few seconds — same failure pattern as on the Mac
So the failure is consistent across two completely different drives/OS combinations, which suggests it's not a filesystem or drive-specific issue but something about the KAO media itself at the physical/servo level. Shutter and disk surface look visually clean, no scratches, identical to the Sony disks.
Has anyone encountered specific compatibility or degradation issues with KAO-brand 128MB MO media? Curious if there's a known manufacturing/coating characteristic that causes this kind of early "can't even get past spin-up" failure, as opposed to gradual media rot.
Testing them now on a PowerBook G4 Titanium (Mac OS 9.2) with a Buffalo USB MO drive (MO-CU2):
Sony-brand disks: mount and read fine
KAO-brand disks (10+ disks, same era/setup): fail identically every time — drive spins up (audible), but the LED never blinks (no seek activity), and the disk ejects automatically after ~10 seconds. No retry clicking sound.
I also tested both on a Windows 11 PC with a different Buffalo USB MO drive (MO-CM640U2):
Sony disks: drive icon appears clearly, Windows reports "disk not readable" (expected, since it's HFS-formatted)
KAO disks: drive icon appears only faintly/intermittently, then ejects after a few seconds — same failure pattern as on the Mac
So the failure is consistent across two completely different drives/OS combinations, which suggests it's not a filesystem or drive-specific issue but something about the KAO media itself at the physical/servo level. Shutter and disk surface look visually clean, no scratches, identical to the Sony disks.
Has anyone encountered specific compatibility or degradation issues with KAO-brand 128MB MO media? Curious if there's a known manufacturing/coating characteristic that causes this kind of early "can't even get past spin-up" failure, as opposed to gradual media rot.
