The ST512 was a thin-film head version of the ST506, per Seagate :
"This increased capacity is accomplished by using the inner portion of the disc
surface that was previously unused and by increasing the disc track density from 255
tracks per inch to 270 tracks per inch To reliably use the inner portion of the disc. The
ST512 uses a new type of read/write head - a "thin film" head."
It was dropped in 1981 due to the lack of a reliable supply of heads and replaced by the
ST412.
-----Original Message-----
From: Tony Duell [mailto:ard.p850ug1@gmail.com]
Sent: Friday, February 03, 2023 9:27 AM
To: Alexandre Souza
Cc: General Discussion: On-Topic and Off-Topic Posts
Subject: [cctalk] Re: Nuking an MFM drive with a magnet, format/servo gone?
On Fri, Feb 3, 2023 at 5:21 PM Alexandre Souza <alexandre.tabajara(a)gmail.com>
wrote:
I thoug the right one was st512...can you enlighten me on this subject Tony?
I've never heard it called that.
It's often called 'ST506' but that drive had a few differences from the later
ones. it didn't support buffered seeks AFAIK. The ST412 did and was the most common of
a family of 3 similar drives (ST406, ST412,
ST419) so it tends to be used as the de-facto name of the interface.
-tony