Subject: WD1002s-shd

From: Joe <[email-masked]>
Date: Sun Mar 2 12:21:01 2003

Found this a few days ago. I think it's a SASI to ST-412 bridge board. Does anyone have more information on it? It has a 50 pin ribbaon cable header on one end. The other end has a 34 pin card edge connector, nearby are two 20 pn ribbon cable headers and a 4 pin molex power cable connector. Anyone have a manual for it?

   Joe

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From: "Eric Smith" <[email-masked]>
Date: Sun Mar 2 12:39:00 2003

Joe wrote:
>   Found this a few days ago. I think it's a SASI to ST-412 bridge board.

No, not SASI.  The host interface was of WD's own devising.  It has eight
data lines, three address lines, select, read and write strobes, an
interrupt and a data transfer request.  There's an eight-register "task
file", containing registers to select the drive, cylinder, head, and
sector, issue commands, read status, and transfer data.

Various small computers from the early to mid 1980s used controllers from
this family.  For instance, the hard disk subsystems from Radio Shack for
the TRS-80.

The WD1010 and WD2010 were basically an (almost) single-chip version of
the WD100x board.

The ATA (IDE) host interface is a direct descendent of this, although not
100% compatible.

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From: Joe <[email-masked]>
Date: Sun Mar 2 17:43:04 2003

Thanks Erik. Any idea what it's good for? or what systems may use it?

    Joe