[sebhc] Shugart 400L Drive

Mark Garlanger garlanger at gmail.com
Fri Oct 13 19:24:39 CDT 2006

On 10/13/06, Lee Hart <leeahart at earthlink.net> wrote:
> Mark Garlanger wrote:
> > Does anyone know if I should be able to use the Shuart 400L floppy as
> > a replacement for the H-17-1 drives? I'm having some problems with a
> > pair I got off of ebay. I thought I would be able to use them since
> > they appear to have the same specs as the Wangco and Seimens drives
> > with just a different door latch. I had read that they have 40 tracks
> > instead of the 35 that the older 400 model had. When I received the
> > drives they had an additional 2" x 2.5" board (with a CAP, a diode,
> > several resistors, a 74LS86 and a 74LS00) which converted a twenty pin
> > connector into the standard edge connector and power cable. I removed
> > this and was able to properly connect it in my H17 case to my
> > hard-sectored controller. The id was set to 1 (third drive), another
> > drive is the last drive on the cable and has the terminating resistor
> > pack. When I try to boot from them, the light comes on, but I receive
> > a '?Boot error' message. It doesn't make any clicks like my other
> > drives do. The disk is spinning, but I don't hear any head movement.
> > This behavior is the same on both drives. Does anyone know if these
> > drives are not compatible with the heath controller? Or maybe some
> > other setting is off, both drives did come with the ID set to 1, but
> > one drive had a '1' sticker on the front and the other had a '2'
> > sticker? Or maybe I got two bad drives?
> Do you have the HDOS "H17" diagnostic program? It runs the drive through
>   its paces, and tells you its maximum step rate, etc.

Yea, I've used it with other drives but with this one, when I select
the drive, the light comes on, stays on for ~45 seconds, then turns
off. The test program is hung during this whole time. Hitting ^C
caused the drive light to come back on for about the same amount of
time, but the computer is still hung. Shift-reset seems to be the only
thing you can do.
This is the same behavior I noticed yesterday before I cut the wires
connected to the spare pins.

> Just about any 5.25" drive will work on the H8 and H89; the challenge is
> to figure out the jumpers, and get them set the way the Heath hardware
> expects. This means individual drive select lines, head loads on select,
> and motors all started by the motor control line.

There appears to be only one jumper block, the text on the circuit board is:


Based on what I see in the manuals, when putting this drive as #3 on
the hard-sectored controller, I should use jumpers HL and 1. All the
others should remain open.
Now with HL now closed, is does sound like the head is loaded upon
select, but it does not sound like the heads are moving at all. The
drive select line is set properly and the motor does spin when any
drive is on. Maybe the drives are bad.

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