Re: Need an 8280 formatted 8" disk

From: Ethan Dicks <>
Date: Mon, 13 Feb 2017 09:08:46 -0500
Message-ID: <>
On Mon, Feb 13, 2017 at 7:54 AM, Rob Clarke <> wrote:
> I'm desperately in need of a known good 8" floppy formatted on an 8280.

An 8280?  Nice.  That's one of those devices I've wanted to fiddle
with for the fun of it (but wouldn't want to have as my primary
storage device).

> After 18 months of occasional work, I now have my 8280 up and running, or at
> least I think I do. DOS board is up and running, the drives are refurbished
> and behaving, and I have a good power source. I can trace signals all the
> way from the FDC to the read/write heads and back again.

Sounds great.

> Nevertheless, using the 2 no-name 8" disks I have, the format fails with an
> error 21 on track 0, sector 1 every time. So, to track the fault down it
> would really help to have a good disk. Either I can post one of my disks to
> someone or, if you hace a spare 8" disk, I'd gladly compensate for that and
> time, postage etc...

I do not have any 8280-formatted media (or a drive), but... I read
that the drive supports two formats: native ~500K GCR and standard
250K MFM "IBM 3740" format.  If you have a working 8" drive on some
other platform, or even just have any DEC RX01 media, you might be
able to start out reading blocks into drive RAM and pulling bytes out
with M-R, as a test of non-write portions of the drive.

I'd also consider writing some BASIC code to try to read different
tracks to make sure the heads dance appropriately.  Without good
media, of course the actual reads will fail, but the positioner should
do the right thing.

In case there is a problem with the heads, is the drive mech of a type
that can be tested on another platform?  (Tandon TM848, for example,
which the photo resembles)

If someone can send you an 8280-formatted disk, that's great (not sure
how many of those are out there), but I think there are some partial
tests you can do with more common media.


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Received on 2017-02-13 15:00:03

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