Seagate 1" Harddisks

Featured models:

For other manufacturers, see the  Microdrive History .

Seagate ST1 Product Line

The first generation, ST1, was first available as 2.5GB and 5.0GB, a 6.0GB model must have been added some time later

The second generation, ST1.2, was available as 4.0GB and 8.0GB:

The third generation, ST1.3, was available as 12GB with ZIF-ATA connector only:

Seagate ST1.3 12GB

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Seagate ST1.3 12GB ST612712DE

The disk has the reduced footprint of 40 × 30 mm², equal to the CF footprint without the guiding notches and the 50-pin connector. This is exactly the same form factor and the same interface as the  Hitachi HMS361008M5CE00 .

Seagate ST1.3 ST612712DE, top view
Seagate ST1.3 

Unlike for most other models, regular Philips #000 screws are used. Unfortunately, the disk is one of the more expensive ones, so I can still resist to open it.

Seagate ST1.3 ST612712DE, bottom view
Seagate ST1.3 bottom view 

Above you can see the slightly damaged latch of the ZIF connector. There are 35 contacts in a staggered 18+17 layout. Although there is a 35-pin to 40-pin ribbon cable used, the pinout is not compatible to regular 40-pin ZIF-ATA. The ribbon just provides two additional ground connections, one additional power connection, and two NC.

Seagate ST1.3 12GB ST612712DE Performance

The data was taken through the supplied USB bridge. The controller is a Genesys Logic GL811E, which is fast enough to make use of the full speed of the drive. The fastest media zone is about 11MB/s, the slowest media zone is about 4.2MB/s giving an average sustained read and write rate of 7.95MB/s.

Seagate ST1.3 ST612712DE read/write transfer diagram

Enclosure: Verbatim Store'n'Go 12GB

Actually, this is the point where I re-discovered my passion for small form factor harddisks: I saw a 12GB "USB Drive", a Verbatim Store'n'Go 12GB (95510), at acceptable price in a shop. Later I realized that it might contain a Cornice Dragon. After a quick check to make sure the drive is working, I disassembled it and was surprised to find a Seagate drive inside.

The enclosure seems to be a generic design with branding option, see the  Excelstor GStor Mini  for more photos. The PCB is about the same size as the disk, 44.5 × 30.1 mm², the USB plug gives a better impression of how small the drive actually is.

PCB with USB bridge
PCB with ZIF-ATA to USB 2.0 bridge 

This is the drive with the protective rubber frame and the 35-pin to 40-pin ZIF ATA connector. The black thing is a tape for additional protection of the ribbon.

Seagate ST1.3 ST612712DE with protectivr rubber frame
Seagate ST1.3 with Rubber Frame 

Seagate ST1.2 8GB

Quick links:    Harddisk   ·   Performance   ·   Enclosure 

Seagate ST1.2 8GB ST68022CF

This is the 8GB CF removable version of the second generation. The disk reports 8,000,004,096 Bytes available, with a mapping of CHS 15501/16/63. Supported ATA modes are PIO-4, MDMA-2 and UDMA-2. As part of the CF+ specification, a maximum power requirement of 330mA is reported.

Seagate ST1.2 ST68022CF, top view
Seagate ST1.2 top view 

Seagate ST1.2 ST68022CF, bottom view
Seagate ST1.2 bottom view 

Seagate ST1.2 8GB Data Transfer Rates

The diagram below was taken on an ICH6R ATA host using a CF-ATA adapter. The read performance using other adapters is similar, except for the USB bridge that was used in the LaCie Carte enclosure. In the original configuration, the read rate is clipped to an almost straight line at 8.34MB/s for the first media zones. I was not able to get a proper consistent write rate, yet.

Seagate ST1.2 ST68022CF

LaCie Carte USB Key

The disk was found inside a "LaCie Carte USB Key", a very slim USB harddisk of about 7-8mm thickness. I forgot to take the dimensions before opening the box.

PCB from the LaCie Carte, top view
PCB from the LaCie Carte, top view 

Although the board features a NEC µPD720133GB ATA to USB bridge, the read rate is clipped to a clean straight line at 8.34MB/s that looked like one single media zone. With a different USB bridge, the fastest media zone was about 9.4MB/s with two more zones above the 8.34MB/s level.

PCB from the LaCie Carte, bottom view
PCB from the LaCie Carte, bottom view 

Seagate ST1.1 6GB

Originally, the ST1.1 series was available with 2.5GB and 5GB. Some time later, Seagate must have added a 6GB version, the ST660211CF.

This is a refurbished model of the Seagate ST 1.1 6GB. There were are at least two different formatting schemes used, where the main difference is the transfer rate of the first media zone of 8.15MB/s compared to 7.70MB/s.

Seagate ST1.1 ST660211CF, top view
Seagate ST1.1 6GB, top view 

Seagate ST1.1 ST660211CF, bottom view
Seagate ST1.1 6GB, bottom view 

Below is the transfer rate diagram of the slightly faster 30 Zone formatting with media zones from 8.15MB/s down to 4.04MB/s and an average sustained read rate of 6.02MB/s.

Seagate ST1.1 ST660211CF, 30 Zones

Below is the transfer rate diagram of the slightly slower 29 Zone formatting with media zones from 7.70MB/s down to 4.06MB/s and an average sustained read rate of 5.90MB/s.

Seagate ST1.1 ST660211CF, 29 Zones

Seagate ST1.1 5GB

This is a refurbished model of the Seagate ST 1.1 5GB.

Seagate ST1.1 ST650211CF, top view
Seagate ST1.1 5GB, top view 

Seagate ST1.1 ST650211CF, bottom view
Seagate ST1.1 5GB, bottom view 

Below is the transfer rate diagram of the Seagate ST1 5GB. Please note that this is from a refurbished model, the data rate of the original version might be different.

Seagate ST1.1 ST650211CF

Hans-Jürgen Reggel   ·   http://www.hjreggel.net/hdtechdat/   ·   2008-06-24 ~ 2008-08-25