Photo: Red Hill.
Another grand old soldier of the MFM era.
Like the notorious Miniscribe 3650, the ST-251 was slow and very noisy, but it tended to keep on going for a good while — unlike some of its over-stressed RLL relatives, which were even worse than the Miniscribe drives.
There were several versions of this long-lived drive: the 28ms ST-251-1 was much faster than the standard model (ST-251-0 or plain ST-251), and then there was the ST-277R, which was a tweaked-up RLL variant. The 277R was, not to put too fine a point on things, a dud to be ranked alongside the notorious Kalok Octagon and the dreadful Samsung SHD-125. Reliability problems with the ST-251 variants cast a pall over the entire company for some years afterwards, which was a shame as both the sluggish ST-251-0 and the surprisingly speedy ST-251-1 were solid, reliable performers.
The ST-251 made a unique hollow knocking noise on start-up, once heard never forgotten, by far the most distinctive sound of any drive yet made. Performance figures are for the ST-251-1.
|Data rate||5 Mbit/sec||Spin rate||3600 RPM|
|Seek time||28ms (or 40)||Actuator||Stepper|
|AT drive type||40 or 44||Form||5.25" half-height|
|ST-251-1||42.8MB||6 thin-film heads|
Note: ST-251 is the correct term. Many references are made elsewhere to the "Seagate ST251", these are in error. See the note at the bottom of the ST-225 entry for details.