15 Aug
2014
15 Aug
'14
10:24 a.m.
I've imaged a little stack of Displaywriter 8" disks and am starting in
on filesystem organization. With an EBCDIC filter I can see the data
plain as day. I've also got experience stitching together the
DisplayWriter files that come from the DOS-based system, so if I could
get the file allocation scheme figured out and lift off whole files from
these disk images, I bet the same conversion code would work on the
resulting data.
I've browsed the manuals on Bitsavers, but of course IBM never intended
their users to actually look at the bytes on the disk. So none of the
information was geared towards revealing the file allocation secrets.
Is there any reference material out there to help me decode (or find)
the file allocation structures?
- David
16 Aug
16 Aug
4:50 a.m.
On Sat, Aug 16, 2014 at 3:24 AM, David Schmidt <david at attglobal.net> wrote:
I've imaged a little stack of Displaywriter
8" disks and am starting in on
filesystem organization.
Would you able to list the diskettes please so I can add to the public
catalogue of known Displaywriter software.
Is there any reference material out there to help me
decode (or find) the
file allocation structures?
The "physical" layout is documented here:
http://bitsavers.trailing-edge.com/pdf/ibm/floppy/GA21-9182-5_Diskette_Gene…
and there are other versions of the document in the same directory.
The DW logical structure more or less follows the physical layout,
however there are new filetypes and extensions. I was planning to
return to building a decoder once I had additional images to work with
so it would be easier to triangulate the DW specifics.
18 Aug
18 Aug
5:25 a.m.
On 8/16/2014 7:50 AM, Nigel Williams wrote:
This was very informative - thanks for that. Nothing specific to the
DW, but at least it lays out what the records look like. I retract my
earlier statement about IBM being tight-lipped about the format. I was
just looking in the wrong directory on Bitsavers. :-)
- David
On Sat, Aug 16, 2014 at 3:24 AM, David Schmidt
<david at attglobal.net> wrote:
These are all notes, minutes, and such from a local municipality;
nothing of any value for preservation, I don't think. They're all
working disks from the secretarial pool. Diskette part numbers are
different from the ones listed in the document below; probably because
they are newer than the document itself. They're all 2D (76 MFM tracks
of 26 sectors, each of 256 bytes; track 0/side 0 is FM with 26 sectors
of 128 bytes).
I've imaged a little stack of Displaywriter
8" disks and am starting in on
filesystem organization.
Would you able to list the diskettes please so I can add to the public
catalogue of known Displaywriter software. Is there any
reference material out there to help me decode (or find) the
file allocation structures?
The "physical" layout is documented here:
http://bitsavers.trailing-edge.com/pdf/ibm/floppy/GA21-9182-5_Diskette_Gene…
16 Aug
16 Aug
9:37 a.m.
On 08/15/2014 10:24 AM, David Schmidt wrote:
I've browsed the manuals on Bitsavers, but of
course IBM never intended
their users to actually look at the bytes on the disk. So none of the
information was geared towards revealing the file allocation secrets.
Is there any reference material out there to help me decode (or find)
the file allocation structures?
I did a DW to (of all things) HTML conversion utility some years back. I
recall that the filesystem (if it could be called that) was a bit odd.
The curious thing that I remember about the data was that all of the
special effects (bolding, underlining) were actual printer codes fro the
IBM daisywheel printer.
If you're desperate, I can see if I can still find my work. I haven't
seen a DW floppy in perhaps a decade.
--Chuck
11:55 a.m.
I wonder whether there was any cross-compatibility of documents and/or filesystem formats
between the Displaywriter and the Datamaster? The Datamaster has double-sided
"2D" drives.
--
Mark J. Blair, NF6X <nf6x at nf6x.net>
http://www.nf6x.net/
2:20 p.m.
On Aug 16, 2014, at 13:19 , Chuck Guzis <cclist at sydex.com> wrote:
On 08/16/2014 11:55 AM, Mark J. Blair wrote:
Good question! I don't know yet.
--
Mark J. Blair, NF6X <nf6x at nf6x.net>
http://www.nf6x.net/
I wonder whether there was any
cross-compatibility of documents
and/or filesystem formats between the Displaywriter and the
Datamaster? The Datamaster has double-sided "2D" drives.
Dunno--is the Datamaster an EBCIDIC machine?
17 Aug
17 Aug
7:54 p.m.
On 08/16/2014 11:55 AM, Mark J. Blair wrote:
I wonder whether there was any cross-compatibility of
documents
and/or filesystem formats between the Displaywriter and the
Datamaster? The Datamaster has double-sided "2D" drives.
I don't know. The DW records the usual System/3 format -- single-sided;
1 track of FM, and 76 tracks of 256 byte MFM sectors. The filesystem
seems to be tailored to the application--there are lists of pointers to
records with attributes like Document name, date, starting lines, extent
table, formatting data...
There is also an allocation bitmap.
Ring any bells?
--Chuck
18 Aug
18 Aug
5:32 a.m.
On 8/16/2014 12:37 PM, Chuck Guzis wrote:
I did a DW to (of all things) HTML conversion utility
some years back. I
recall that the filesystem (if it could be called that) was a bit odd.
The curious thing that I remember about the data was that all of the
special effects (bolding, underlining) were actual printer codes fro the
IBM daisywheel printer.
I've heard that before... a bunch of the intelligence was actually in
the printer. Hmmm. Maybe a little like PostScript in that regard.
If you're desperate, I can see if I can still find
my work. I haven't
seen a DW floppy in perhaps a decade.
Thanks, Chuck. [He found and sent the secret decoder program.]
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days inactive
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cclist＠sydex.com -
david＠attglobal.net -
nf6x＠nf6x.net -
nw＠retrocomputingtasmania.com