[Coco] 3.5" drives
kevdig at hypersurf.com
Mon Aug 23 11:41:38 EDT 2004
I spent much of yesterday trying to get OS9 to
boot. To the casual observer I imagine this would have
resembled watching the 3 stooges try to get a cray running.
I had this thing scattered across the room. Turns out the
cable between the "HCA" and interface board was backwards.
Its a wonder I didn't blow it up!
After more than 10 years it seems to run fine. The
old miniscribe ST-506 40 M drive seems fine. All the
floppies I tried to read seem fine.
The HCA (Host Computer Adapter), the thing that
plugs into the slot is fairly simple. It contains a 65C52
serial chip, a 65xx (PIA) for parallel and ?, a RTC (DS1287),
and an "auto boot ROM".
In the box containing the hard drive is the interface
card, a WD1002-05G. It has 4 40 pin WD chips: WD1614AL-00,
WD1010AL-00, WD2797PL-02 (floppy chip), and a WD1015PL-00.
It can control three ST-506 hard drives and three floppies.
The WDDisk driver manual mentions high capacity floppy
operation: both 250/500 kbit bit rates and 300/360 rpm speeds
are mentioned. The little satellite board does more than control
motor speeds. It has only two chips: a 74ls157 and a 7438.
Will this also work with 3.5" HD floppies?
I did a dcheck on the hard drive and all the floppies.
I got no read or I/O errors. How good an indication is this
of the state of my media?
80 columns on a composite TV is hard to read.
P.S.: Anybody play sub battle simulator. I spent hours
playing this thing back then. Its a bloody good
thing I was'nt a sub commander in WWII!
Willard Goosey wrote:
>>Date: Sat, 21 Aug 2004 08:55:55 -0700
>>From: Kevin Diggs <kevdig at hypersurf.com>
>>I believe the FHL eliminator that I have can also handle high
>>density drives. The manuals mention some simple circuit that
>>you have to build (I think it has something to do with motor
> I've heard of the eliminator, but I don't know what it uses for a
> floppy controller. My foggy memory says something about a WD1002, but
> that sounds like a hard-drive controller chip, to me.
> I'd be interested in more crunchy technical info about the
More information about the Coco