Got DSM-11 running, any manuals online?

Warner Losh imp at bsdimp.com
Sat Jan 9 16:59:34 CST 2021


On Sat, Jan 9, 2021, 2:55 PM David Gesswein <djg at pdp8online.com> wrote:

> On Sat, Jan 09, 2021 at 01:06:19PM -0700, Warner Losh wrote:
> >
> > DEC standard 144 of any help?
> >
> http://bitsavers.org/pdf/dec/standards/EL-00144_B_DEC_STD_144_Disk_Standard_for_Recording_and_Handling_Bad_Sectors_Nov76.pdf
> >
> > Warner
> >
>
> Thanks for looking.
>
> That standard is only capable of marking bad sectors. It doesn't have the
> information on where the bad sectors were remapped to. I took a quick look
> at the DSM image. It looks like cylinder 511 is where the controller
> tables are. This cylinder does have a different format. The data didn't
> match this standard.
>

The rainbow has a different way to mark this stuff. Maybe there is some
reuse in it? See "on disk format" in
http://www.bitsavers.org/pdf/dec/rainbow/ms-dos/QV068-GZ_Rainbow_MS-DOS_V2.05_Technical_Documentation_Nov84.pdf
which seemed oddly complex for such an early standard. It talks about N
spare tracks that remapped sectors land in...  I've never had a disk image
that uses them though... worth a shot in the absence of other data...

Warner

>


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