Classic 3.5-inch slim-line IDE hard drive from Seagate’s early 1990s lineup. The Seagate ST3120A offers 107 MB (approximately 120 MB unformatted) of reliable storage, making it a perfect choice for restoring vintage 386, 486, and early Pentium PCs.

*** Hard drive is tested for no bad sectors and is formatted as a FAT32 partition.

Key Specifications:

• Capacity: 107 MB formatted (≈120 MB unformatted)
• Form Factor: 3.5-inch Slim-Line (SL) – low-profile design
• Interface: IDE / ATA (AT-Bus, 40-pin)
• Spindle Speed: 3,200 – 3,211 RPM
• Cache Buffer: 32 KB
• Average Seek Time: ~17–19 ms
• Data Transfer Rate: Up to 8–10 MB/s (PIO Mode)
• Geometry: 1024 cylinders / 12 heads / 17 sectors
• Power: Standard +5V / +12V Molex connector
• Jumper Configurable: Master / Slave / Cable Select

Built for Retro Computing

This genuine Seagate drive was widely used in mid-1990s desktop computers. It excels in period-correct restorations, DOS, Windows 3.1, Windows 95/98 systems, and retro gaming builds.

*** Hard drive is tested for good S.M.A.R.T. , no bad sectors and is formatted as an NTFS partition.

Here are the key specifications:

• Capacity: 160 GB (160,000,000,000 bytes / 160 × 10⁹ bytes; ~149 GiB usable after formatting)
• Form Factor: 3.5-inch
• Interface: Ultra ATA/100 (also called ATA-6, Parallel ATA / IDE / PATA) — maximum burst transfer rate up to 100 MB/s
• Spindle Speed (RPM): 7,200 RPM
• Cache / Buffer: 8 MB
• Average Seek Time: ~8.5–9 ms (typical read)
• Average Latency: ~4.16 ms
• Sustained Data Transfer Rate (outer zones, max): Up to ~78–85 MB/s (depending on source; perpendicular tech helped achieve higher densities)
• Internal Data Transfer Rate (max): Around 1,000–1,200 Mbit/s (~125–150 MB/s theoretical, but sustained lower)
• Bytes per Sector: 512
• Guaranteed Sectors: 312,581,808
• Recording Technology: Perpendicular Magnetic Recording (PMR) — first major Seagate desktop series to use this
• Number of Platters / Heads: Typically 1–2 platters (high-density 160 GB/platter class at launch)
• Power Connector: Standard 4-pin Molex

*** Hard drive is tested for good S.M.A.R.T. , no bad sectors and is formatted as an NTFS partition.

Here are the key specifications:

• Capacity: 160 GB (160,000,000,000 bytes / 160 × 10⁹ bytes; approximately 149 GiB usable)
• Form Factor: 3.5-inch
• Interface: Ultra ATA/100 (also known as ATA-6 or Parallel ATA / IDE / PATA)
• Spindle Speed (RPM): 7,200 RPM
• Cache / Buffer: 2 MB
• Average Seek Time: 8.5 ms (read typical)
• Average Latency: 4.16 ms
• Sustained Data Transfer Rate (outer diameter, max): ~58 MB/s
• Internal Data Transfer Rate (max): ~85.4 MB/s
• Bytes per Sector: 512
• Guaranteed Sectors: 312,581,808
• Number of Platters / Heads: Typically 2–3 platters (with 80 GB per platter technology at the time)
• Power Connector: Standard 4-pin Molex
• Other Features: Fluid Dynamic Bearing (FDB) motor for quieter operation and reliability; part of Seagate’s high-density 7200 RPM lineup

This drive was known for good performance in its era, especially compared to 5400 RPM models, and was commonly used in desktop PCs before the shift to SATA interfaces.

*** Hard drive is tested for good S.M.A.R.T. , no bad sectors and is formatted as an NTFS partition.

Here are the key specifications based on the official Seagate Barracuda 7200.7 Product Manual (covers ST380011A) and consistent historical/vendor data:

• Capacity: 80 GB (formatted; actual usable space ~74–75 GiB due to binary vs. decimal calculation and overhead)
• Interface: IDE / PATA (Parallel ATA), Ultra ATA/100 (ATA-6), backward compatible with ATA/66, ATA/33, PIO modes, etc. → Max theoretical burst transfer rate: 100 MB/s
• Form Factor: 3.5-inch (standard desktop, ~1-inch / 26.1 mm height)
• Spindle Speed: 7200 RPM
• Cache / Buffer: 2 MB
• Average Seek Time: ~8.5–9.5 ms (read/write; typical ~9.5 ms read from data sheets)
• Average Latency: ~4.16 ms (at 7200 RPM)
• Platter / Head Configuration: Typically 1 platter / 2 heads (single-platter design using ~80 GB/platter density technology)
• Other Features:
  • Fluid Dynamic Bearing (FDB) motor (SoftSonic in some references) for quieter, smoother, and more reliable operation with reduced vibration
  • 3D Defense System (Seagate’s data protection: shock sensors, embedded servo, recovery features)
  • S.M.A.R.T. support for predictive failure monitoring
  • Enhanced shock protection and thermal monitoring
  • Low power consumption and good acoustics for a 7200 RPM drive
• Power Consumption: Typical for the era (~6–9W active; standard 4-pin Molex power connector)
• MTBF (Mean Time Between Failures): ~600,000–1 million hours (manufacturer claim for Barracuda 7200.7 series)
• Acoustics: Idle ~2.8–3.0 bels (~28–30 dB); seek ~3.0–3.4 bels (~30–34 dB) (relatively quiet for class, thanks to FDB)
• Compatibility: Works with older IDE/ATA motherboards; jumper settings for Master/Slave/Cable Select (standard Seagate layout—check drive label: typically Master: jumper on pins 7-8 or as marked, Slave: no jumper, CS: jumper on pins 5-6 for cable-determined role; use 80-wire cable for ATA/100 performance)
• Jumper Settings (typical Seagate Barracuda ATA):
  • Master (or single drive): Jumper closed on designated pins
  • Slave: No jumper
  • Cable Select (CS): Jumper on CS pins; recommended for plug-and-play
  • Additional jumper options: Limit capacity (for legacy BIOS compatibility, e.g., to 32 GB or 137 GB LBA)

This drive delivered strong performance for its time—sequential transfers often 50–85 MB/s (outer zones higher, up to ~85 MB/s internal), quick seeks, and better reliability/noise than many 5400 RPM drives. It was a go-to choice for gaming, office, and general desktop use, competing with Western Digital Caviar WD800BB, Maxtor DiamondMax 9, and Samsung SpinPoint P80 equivalents.

*** Hard drive is tested for good S.M.A.R.T. , no bad sectors and is formatted as an NTFS partition. Actual drive is pictured.

Here are the key specifications based on the official Seagate Barracuda 7200.9 PATA Product Manual (Rev. C/F) and consistent vendor/historical data:

• Capacity: 80 GB (formatted; actual usable space ~74–75 GiB due to binary vs. decimal calculation and overhead)
• Interface: IDE / PATA (Parallel ATA), Ultra ATA/100 (ATA-6), backward compatible with ATA/66, ATA/33, PIO modes, etc. → Max theoretical burst transfer rate: 100 MB/s
• Form Factor: 3.5-inch (standard desktop, ~1-inch / 26.1 mm height)
• Spindle Speed: 7200 RPM
• Cache / Buffer: 2 MB
• Average Seek Time: ~11 ms (read/write; typical value from manual and listings)
• Average Latency: ~4.16 ms (at 7200 RPM)
• Platter / Head Configuration: Typically 1 platter / 2 heads (using high-density ~80–100 GB/platter technology of the era; single-platter design for this capacity point in the 7200.9 lineup)
• Other Features:
  • Seagate’s SoftSonic motor (FDB or similar for reduced noise/vibration)
  • Enhanced G-Force Protection and shock sensors
  • S.M.A.R.T. support for health monitoring and predictive failure
  • Quiet operation focus (good acoustics for a 7200 RPM drive)
  • Supports legacy LBA addressing (16383 cylinders / 16 heads / 63 sectors in CHS mode for compatibility)
• Power Consumption: Typical for the era (~6–9W active; standard 4-pin Molex power connector)
• MTBF (Mean Time Between Failures): ~600,000–1 million hours (manufacturer claim for Barracuda 7200.9 series)
• Acoustics: Idle ~28–30 dB; seek ~30–34 dB (relatively quiet for class)
• Compatibility: Works with older IDE/ATA motherboards; jumper settings for Master/Slave/Cable Select (standard Seagate layout—check drive label: typically Master: jumper on specific pins (e.g., 7-8), Slave: no jumper, CS: jumper on pins 5-6 for cable-determined role; use 80-wire cable for ATA/100 speeds)
• Jumper Settings (typical Seagate Barracuda ATA):
  • Master (or single drive): Jumper closed on designated pins
  • Slave: No jumper
  • Cable Select (CS): Jumper on CS pins; recommended for modern installs

This drive provided strong performance for its time—sequential transfers often 50–70+ MB/s in outer zones, quick seeks, and better reliability/noise than many 5400 RPM alternatives. It was popular for budget builds, upgrades, and as a secondary drive alongside SATA in transitional systems.

*** Hard drive is tested for good S.M.A.R.T. , no bad sectors and is formatted as an NTFS partition. Actual drive is pictured.

Here are the key specifications based on official Seagate product manuals (U Series 6 Family Product Manual, Rev. B), installation guides, and consistent historical/vendor data:

• Capacity: 80 GB (formatted; actual usable space ~74–75 GiB due to binary vs. decimal calculation and overhead)
• Interface: IDE / PATA (Parallel ATA), Ultra ATA/100 (ATA-6), backward compatible with ATA/66, ATA/33, PIO modes, etc. → Max theoretical burst transfer rate: 100 MB/s
• Form Factor: 3.5-inch (standard desktop, ~1-inch / 26.1 mm height)
• Spindle Speed: 5400 RPM
• Cache / Buffer: 2 MB
• Average Seek Time: ~8.9–9.5 ms (read/write; typical for the series, with access time ~14–15 ms including latency)
• Average Latency: ~5.6 ms (at 5400 RPM)
• Platter / Head Configuration: Typically 2 platters / 4 heads (using ~40 GB/platter density technology common in Seagate’s U Series at the time)
• Other Features:
  • 3D Defense System (Seagate’s data protection suite: includes shock sensors, embedded servo for better error handling, and data recovery tools)
  • Quiet operation emphasis (lower RPM helps reduce noise/vibration compared to 7200 RPM drives)
  • Shock resistance (non-operating up to ~350G typical for series)
  • S.M.A.R.T. support for predictive monitoring
  • Fluid Dynamic Bearing (FDB) motor in many units for smoother, quieter spins (though some early U6 variants used ball bearings)
• Power Consumption: Typical for the era (~5–7W active; standard 4-pin Molex power connector)
• MTBF (Mean Time Between Failures): ~600,000–1 million hours (manufacturer claim for U Series; some sources list up to 1.2M hours)
• Acoustics: Idle ~26–30 dB; seek ~30–34 dB (relatively quiet due to 5400 RPM design)
• Compatibility: Works with older IDE/ATA motherboards; jumper settings for Master/Slave/Cable Select (standard Seagate layout—check drive label: typically Master: jumper on pins 7-8 or as marked, Slave: no jumper, CS: jumper on pins 5-6 for cable-determined role; use 80-wire cable for best ATA/100 performance)
• Jumper Settings (typical Seagate U Series ATA):
  • Master (or single drive): Jumper closed on designated pins (often center or labeled)
  • Slave: No jumper
  • Cable Select (CS): Jumper on CS pins; recommended for plug-and-play setups

This drive offered good value and reliability for everyday use (office, web, light multimedia), with lower heat/noise than 7200 RPM competitors, though sustained transfers were slower (~30–45 MB/s outer zones). It was part of Seagate’s U Series lineup (not the faster Barracuda 7200.x series, despite some vendor mix-ups).

*** Hard drive is tested for good S.M.A.R.T. , no bad sectors and is formatted as a Fat 32 partition.

Key Specifications

• Capacity: 261 MB (formatted; unformatted/raw ~290 MB)
• Interface: IDE / ATA-1 (early Parallel ATA, 40-pin connector)
• Form Factor: 3.5-inch slimline/low-profile (standard 3.5″ bay compatible, dimensions approx. 101.6 mm × 26.1 mm height)
• Rotation Speed (Spindle Speed): 3811 RPM (unusual non-standard speed for the era, slower than typical 3600 or 5400 RPM drives)
• Cache/Buffer: 64 KB (segmented)
• Geometry (Cylinders / Heads / Sectors): 1001 / 15 / 34 (translated; native may differ slightly due to translation for IDE BIOS limits)
• Platter Count: 2
• Seek Times:
  • Average/Random seek: ~16 ms
  • Track-to-track seek: ~4.4–5 ms
• Data Transfer Rate:
  • Internal: ~2.5 MB/s
  • External (burst): Up to ~6 MB/s (PIO mode, typical for ATA-1)
• Recording Method: RLL 1/7
• Power Connector: Standard 4-pin Molex
• Power Consumption: Idle ~2.5 W, seek/read/write ~4–4.6 W, standby ~1.3 W
• Operating Temperature: 5°C to 55°C
• MTBF (Mean Time Between Failures): ~250,000 hours (manufacturer rating)
• Warranty (original): 24 months
• Other Features: Lift/lock/parking heads (YES), ECC support, no onboard jumper details universally documented but standard Master/Slave/Cable Select configuration via jumpers on the drive PCB

This drive predates faster ATA modes (e.g., ATA-2/UDMA), so it tops out at basic PIO transfers—very slow by any modern standard (real-world throughput often under 3–4 MB/s). It’s a classic “budget” or mainstream drive from Seagate’s early 1990s lineup, similar in era and performance to models like the ST351A-X or Conner/Maxtor contemporaries.

*** Hard drive is tested for good S.M.A.R.T. , no bad sectors and is formatted as a Fat 32 partition.

Key Specifications:

• Model: ST36531A
• Capacity: 6.5 GB
• Form Factor: 3.5-inch
• Interface: IDE (Integrated Drive Electronics) / Ultra ATA/33 (ATA-4)
• Rotational Speed: 5400 RPM (Revolutions Per Minute)
• Cache: 128 KB
• Data Transfer Rate (Max): 33 MB/s (Megabytes per second)
• Technology: PATA (Parallel ATA)

• Bytes per Sector: 512
• Seek Time (Avg/Max): 11 ms (average) / 19.8 ms (max)
• Physical Dimensions: Approx. 0.78″ (H) x 3.97″ (W) x 5.73″ (D)
• Application: Internal desktop/server storage

• Capacity: 40 GB
• Interface: IDE Ultra ATA/100
• Spindle Speed: 7200 RPM
• Buffer Size: 2 MB
• Average Seek Time: 9.4 ms (read)
• Average Latency: 4.16 ms
• Form Factor: 3.5-inch
• Data Transfer Rate: Up to 100 MB/s (burst)

*** Hard drive is tested for good S.M.A.R.T. , no bad sectors and is formatted as a Fat 32 partition.

• Capacity: 40 GB
• Interface: IDE Ultra ATA/100
• Spindle Speed: 7200 RPM
• Buffer Size: 2 MB
• Average Seek Time: 9.5 ms (read), 10.5 ms (write)
• Average Latency: 4.16 ms
• Form Factor: 3.5-inch
• Data Transfer Rate: Up to 100 MB/s (burst)
• Sector Size: 512 bytes
• Features: Fluid Dynamic Bearing (FDB) motor for quiet operation, S.M.A.R.T. support, SeaShield cover for ESD protection

*** Hard drive is tested for good S.M.A.R.T. , no bad sectors and is formatted as a Fat 32 partition.