Replacements for ST-406/ST-512 drives

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Sun Feb 6 12:46:16 2005

>
> OK, here is something I have not been able to find. Are there any
> replacements out there for ST-406 or ST-512 interface hard drives. I know

I am going to assume you mean ST506 and ST412. They're much the same
interface, actually .

> there is a lot of NOS and other old pulls floating around, but is there
> anything that would drop in and let me use a CF or similar device? I have

I don;t know of a dtop-in device. The problem is that the ST506/412
interface is a 'raw' interface. The data on the connector is essentially
the bitstream to/from the head. There is no assumption made about the
sector format, not even that the data is in 8 bit bytes. Of course there
are some restrictions on what the bit stream can be, but not many...

We've discussed this here in the past. The simplest solution would be to
sample the write-data line at, say, 16 times the data rate (so around
80MHz), then save the samples in the CF card. When you're not writing you
'play back; the cotnents of the CF card at 80MHz. Of course this is
inefficient in terms of storage, but CF cards are so much larger than the
ST506 drive that this doesn't matter.

You need a fair bit of logic to get this to work correctly, it's not a
trivial job. But it is something I should consider thinking about as I,
too, have plenty of machines using such drives.

-tony
Received on Sun Feb 06 2005 - 12:46:16 GMT