Vintage Seagate ST-157A 45MB IDE Hard Drive — BOOTS DOS, FULLY TESTED — PERFECT For Sale

RARE Vintage Seagate ST-157A-1 IDE hard drive 45MB.
NEAR MINT CONDITION — MUSEUM QUALITY!
Early, Classic Seagate hard drive.
Originally purchased directly from Seagate distribution on Sept 12, 1991.
This is the high-speed version: "-1" indicates 28ms (vs standard 40ms).
SN: 87969894

• Was removed by our service dept decades ago during a routine upgrade and has been in protected storage since.
• As vintage drives go, this particular drive is relatively quiet.
• Reformatted and MS-DOS 6.22 freshly installed.
• Scandisk full surface scan shows zero errors (see screenshot).
• Chkdsk shows zero errors (see screenshot).
• Should boot right up in any compatible system.
• In order to boot to DOS, set the drive parameters as: CHS = 560 / 6 / 26.
  • The 'auto-detect' feature in some BIOS may not detect this drive or may set different parameters; if so, the drive will not boot.
  • It is best to manually set these parameters in the BIOS with user defined drive type 47 (if available in BIOS).
  • 560/6/26 are the native CHS parameters and give the highest capacity.
  • Different CHS translation parameters can be used for this drive (ex. 733/7/17 or 1024/5/17), but will give slightly lower capacity.
  • For BIOS which has no user-defined drive parameters capability, the standard AT drive table type 14 (733/7/17) should work fine.
    • (Note: if you need 733/7/17, let me know when ordering and I will reformat and reload DOS with these parameters)
  • Note that any change in the CHS parameters will require re-initialization and reformatting.
• Also, please read discussion below...
• Clean, excellent cosmetic and mechanical condition.

You will receive exactly the item you see in the photos.

Shipped via fast USPS Ground Advantage with full tracking. Shipped from a USPS regional SCF (Sectional Center Facility) so delivery anywhere within the U.S. is only a few days away (excluding the occasional USPS misdirect).

Returns accepted if you have a good reason and returned in original condition, but there may be a retesting fee. Generally, shipping will not be refunded.

Discussion: All Seagate 100-series drives (MFM, RLL and IDE) tended to have stiction issues from the very beginning. Stiction is the microscopic attraction between two surfaces requiring force to overcome. During normal operation, the read/write heads fly over the disc surface on a cushion of air pulled along by the rotation of the disc. When the disc stops rotating, the head has to land. In the earliest drives the heads landed randomly wherever they happened to be, which would usually be directly on the last accessed data surface. But if the drive was later bumped, the head resting directly on the disc could damage the surface, potentially causing data loss. To prevent this, a special head parking utility could be used to move the heads to a specially designated non-data landing track. As a significant improvement, the ST-157A features autopark, which, upon power-down, automatically moves the head to a special landing track. Unfortunately another problem arose: stiction, a phenomenon which affects all hard drives. Drives in regular use generally had no problems, but drives allowed to sit unused would develop increasing stiction over time and sometimes would not spin up. Basically, the spindle motors on the Seagate 100 series drives were not powerful enough to break strong stiction. If stiction is not broken, the drive cannot spin. Fortunately, there is a simple trick to break the stiction on the 100-series to allow the drive to spin again: if you buy a Seagate 100-series drive from us and encounter stiction (drive won't spin), please contact me and I'll try to help. Stiction is a problem for all hard drives, but in later years was largely overcome by better coatings on disc surfaces, and by unloading the heads from the disc surfaces during the parking process.