1 Aug
2010
1 Aug
'10
12:24 p.m.
First on my bench will be a bunch (8 or so) of Data General 800/1200 machines and a few
Nova 2's. I can think of several questions so far to get me started down the path:
1) A number of the 1200 machines have broken front panel toggle switches (the switch
handle was broken off and lost). Some are spring return to center, some are just two
position. Before I take the approach of robbing one of the machines for front panel
switches, is there someplace that I can purchase exactly idential (both electrically and
cosmetically) switches, or does some one have donor switches available for trade? I am a
stickler for completely identical parts, especially for front panel switches :) I was
hoping someone had been down this road before and knew the switch model #'s, etc.
2) I have quite a number (maybe around six or seven) of rackmount dual cassette tape units
for these machines. I seem to recall that they use cassette tapes that are not identical
to the standard common audio cassettes available today. Is anyone aware of where these
special tapes can be purchased new?
3) With these machines I got a very large (several crates) library of cassette tapes as
well as paper tapes, most appeared to be DG software rather than user data/backups. Are we
pretty sure that most software for these machines has been archived somewhere, or should I
send these tapes off to Al et. al. to have them read and saved for posterity before I put
them in a questionable drive? As old as these tapes are, I wouldn't be suprised if one
read was all they will allow.
4) Like #3 above, I have maybe 8 or 10 accounting storage boxes full of schematics &
docs for all the circuit cards for the cpu's, interfaces, and peripherals mentioned
above. I don't know what the current state of the DG archival project is. Is it likely
that all these docs are already archived somewhere?
Thanks in advance for any sage advice!
Best,
J
2 Aug
2 Aug
5:52 p.m.
Hi,
On 01.08.2010 19:29, Al Kossow wrote:
On 8/1/10 9:24 AM, Jay West wrote:
I for example have a DG Nova 2 and nearly *NO* information about it. All I know is that
the PSU and
lights are OK. And that I can play around a bit. I have no reliable documentation. And no
clue how
to hook up a TTY or load software and all the like...
That might sound a bit stupid... but... I got frustrated by the lack of *everything* for
my Nova.
All I have for the machine is plenty of core memory...
Why is DG stuff not put onto Bitsavers?
Regards,
Philipp
--
http://www.hachti.de
Are we pretty sure that most software for these
machines has been
archived somewhere, or should I send these tapes off to Al et. al. to
have them read
I've been referring all DG software offers to Bruce Ray at Wild Hare. 
3 Aug
3 Aug
9:28 a.m.
On Monday, August 02, 2010, Philipp Hachtmann wrote:
I for example have a DG Nova 2 and nearly *NO*
information about it.
All I know is that the PSU and lights are OK. And that I can play
around a bit. I have no reliable documentation. And no clue how to
hook up a TTY or load software and all the like...
That might sound a bit stupid... but... I got frustrated by the lack
of *everything* for my Nova. All I have for the machine is plenty of
core memory...
Why is DG stuff not put onto Bitsavers?
Because EMC (the current owners of the IPO) would send lawyers at Al so
quickly, your head would spin.
There however has been some talk of someone negotiating with EMC to get
some sort of hobbyist license/distribution for some of the software.
Check the list archives - it has been talked about before a few times.
Pat
--
Purdue University Research Computing --- http://www.rcac.purdue.edu/
The Computer Refuge --- http://computer-refuge.org
9:41 a.m.
On Tuesday, August 03, 2010, Patrick Finnegan wrote:
On Monday, August 02, 2010, Philipp Hachtmann wrote:
Oops, that's supposed to read "IP" as in intellectual property.
Pat
--
Purdue University Research Computing --- http://www.rcac.purdue.edu/
The Computer Refuge --- http://computer-refuge.org
I for example have a DG Nova 2 and nearly *NO*
information about
it. All I know is that the PSU and lights are OK. And that I can
play around a bit. I have no reliable documentation. And no clue
how to hook up a TTY or load software and all the like...
That might sound a bit stupid... but... I got frustrated by the
lack of *everything* for my Nova. All I have for the machine is
plenty of core memory...
Why is DG stuff not put onto Bitsavers?
Because EMC (the current owners of the IPO) would send lawyers at Al
so quickly, your head would spin. 
4 Aug
4 Aug
6:42 a.m.
On Mon, 2 Aug 2010, Philipp Hachtmann wrote:
I for example have a DG Nova 2 and nearly *NO*
information about it. All I
know is that the PSU and lights are OK. And that I can play around a bit. I
have no reliable documentation. And no clue how to hook up a TTY or load
software and all the like...
That might sound a bit stupid... but... I got frustrated by the lack of
*everything* for my Nova. All I have for the machine is plenty of core
memory...
Why is DG stuff not put onto Bitsavers?
Hmm, what is wrong with the DG stuff that is actually on Bitsavers? I can
find programming information, schematics of the Nova 2, programming
guides, bootstrap loader listings etc. Or did I miss something you
may have told me some time ago?
Christian
1 Aug
1 Aug
1:44 p.m.
Jay West wrote :
>2) I have quite a number (maybe around six or
seven) of rackmount
> dual cassette tape units for these machines. I seem to recall that
> they use cassette tapes that are not identical to the standard
> common audio cassettes available today. Is anyone aware of where
> these special tapes can be purchased new?
If they are identical to the ones I'm thinking of, they have a notch
at the back. This notch of off-center. It enables you to test whether
your are accessing side A or side B.
I've used them extensively in Philips equipment, but they were also
used by Facit and others.
The capacity is 250k bytes per side, and the format is called ECMA34
Good luck
1:51 p.m.
----- Original Message -----
From: "Nico de Jong" <nico at farumdata.dk>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Sent: Sunday, August 01, 2010 7:44 PM
Subject: Re: DG 800/1200 questions
Jay West wrote :
I seem to remember that the tape is "stiffer" then the one in audio
cassettes. The magnetic coating is also different, in order to keep
the bits "square". Normal audio could be used, but gives errors when
reading (IIRC)
>2) I have quite a number (maybe around six or
seven) of rackmount dual
>cassette tape units for these machines. I seem to recall that they use
>cassette tapes that are not identical to the standard common audio
>cassettes available today. Is anyone aware of where these special tapes
>can be purchased new?
If they are identical to the ones I'm thinking of, they have a notch
at the back. This notch of off-center. It enables you to test whether
your are accessing side A or side B.
I've used them extensively in Philips equipment, but they were also
used by Facit and others.
The capacity is 250k bytes per side, and the format is called ECMA34
2:58 p.m.
>2) I have
quite a number (maybe around six or seven) of rackmount
> dual cassette tape units for these machines. I seem to recall that
> they use cassette tapes that are not identical to the standard
> common audio cassettes available today. Is anyone aware of where
> these special tapes can be purchased new?
If they are identical to the ones I'm thinking of, they have a notch
at the back. This notch of off-center. It enables you to test whether
your are accessing side A or side B.
I've used them extensively in Philips equipment, but they were also
used by Facit and others.
The capacity is 250k bytes per side, and the format is called ECMA34 
3:37 p.m.
>2) I have quite a number (maybe around six or
seven) of rackmount
> dual cassette tape units for these machines. I seem to recall that
> they use cassette tapes that are not identical to the standard
> common audio cassettes available today. Is anyone aware of where
> these special tapes can be purchased new?
If they are identical to the ones I'm thinking of, they have a notch
at the back. This notch of off-center. It enables you to test whether
your are accessing side A or side B.
I've used them extensively in Philips equipment, but they were also
used by Facit and others.
The capacity is 250k bytes per side, and the format is called ECMA34
1 Aug
1 Aug
6:42 p.m.
Tony wrote...
While EGMA34 was a very common format for such
cassettes, it was not the
only one (AFAIK). I am sure I have sene at least one tape drive that uses
such cassetes and uses at totally different format. The notch may well be
used to ensure the cassette can only be fitted one way round with soem
formats -- which use the entire width of the tape in one go.
From what I skimmed in some docs, it looks like these DG tape units use the
entire
width of the tape. But no way to fake higher coercivity :\
But alas I have no idea where you'd get the
casssettes now.
These units are in mint shape, was hoping they wouldn't be
paperweights :\
J
7:07 p.m.
On 1 Aug 2010 at 17:42, Jay West wrote:
See http://tinyurl.com/24z4aoc
Are we talking about saturation remanence or coercivity? The Hc of
computer and audio tapes are approximately the same, but the Mr is
quite a bit different.
On the other hand, if ordinary gamma ferric oxide audio tape doesn't
work, CrO2 audio tape might be an option.
FWIW,
Chuck
From what I
skimmed in some docs, it looks like these DG tape units
use the
entire width of the tape. But no way to fake higher coercivity :\
But alas I have no idea where you'd get the
casssettes now.
These units are in mint shape, was hoping they wouldn't be
paperweights :\
2 Aug
2 Aug
2:24 p.m.
Are we talking about saturation remanence or
coercivity? The Hc of
computer and audio tapes are approximately the same, but the Mr is
quite a bit different.
I'd assumed it was the coercivity that was differnt, but mayne it's the
remanence. I will admit I've not done any measurement :-).
I am pretty sure that audio cassetes (even with a notch cut in them) do
not work well in ECMA34 tape drives. And that the data tapes make lousy
audio tapes at any normal bias setting.
-tony
4 Aug
4 Aug
8:32 p.m.
At 7:21 pm +0100 2010/08/02, Tony Duell wrote:
How many tapes do you need? It's possible there are a few around in
people's junk boxes, if you need <10 or so...
If there's reason to believe they'd work, I have around a hundred TU60
cassettes still sealed in their original packaging.
--
Kevin Schoedel <schoedel at kw.igs.net> VA3TCS
But alas I have no idea where you'd get the
casssettes now.
These units are in mint shape, was hoping they wouldn't be
paperweights :\
1 Aug
1 Aug
3:03 p.m.
>2) I have
quite a number (maybe around six or seven) of rackmount
> dual cassette tape units for these machines. I seem to recall that
> they use cassette tapes that are not identical to the standard
> common audio cassettes available today. Is anyone aware of where
> these special tapes can be purchased new?
If they are identical to the ones I'm thinking of, they have a notch
at the back. This notch of off-center. It enables you to test whether
your are accessing side A or side B.
I've used them extensively in Philips equipment, but they were also
used by Facit and others.
The capacity is 250k bytes per side, and the format is called ECMA34 
9:13 p.m.
One thing that I forgot to mention in my earlier
msessag eis that the
tape is differnet to that found in audio compact cassettes (I believe the
data tapes have a higher coercivity). So nothcing the shells of audio
cassettes is unlikely to produce reliable data tapes.
High-quality VHS video tape? Or Metal cassetes?
2 Aug
2 Aug
2:27 p.m.
> data tapes have a higher coercivity). So nothcing
the shells of audio
> cassettes is unlikely to produce reliable data tapes.
What I meant to say was that nothing that's supplied in normal audio
cassette sheels seems to work as reliable data tape in ECMA34 (or
similar) drives...
High-quality VHS video tape? Or Metal cassetes?
I have never tried 'metal' tapes... maybne worth a try...
And if you want to try slicing down 1/2" video tape into the right width
for these cassetes, I wish you luck :-))
-tony
1 Aug
1 Aug
3:14 p.m.
On 2010 Aug 1, at 9:24 AM, Jay West wrote:
First on my bench will be a bunch (8 or so) of Data
General 800/1200
machines and a few Nova 2's. I can think of several questions so far
to get me started down the path:
1) A number of the 1200 machines have broken front panel toggle
switches (the switch handle was broken off and lost). Some are spring
return to center, some are just two position. Before I take the
approach of robbing one of the machines for front panel switches, is
there someplace that I can purchase exactly idential (both
electrically and cosmetically) switches, or does some one have donor
switches available for trade? I am a stickler for completely identical
parts, especially for front panel switches :) I was hoping someone had
been down this road before and knew the switch model #'s, etc.
Jay, is this the front panel in the first picture on the wikipedia page?
http://en.wikipedia.org/wiki/Data_General_Nova
If those are 'standard size' mini-toggle switches, they may be C&K
switches (typically having a red body).
C&K switches tend to be well-marked with a type number stamped in the
metal, and are fairly prevalent in equipment from the period. I have
their catalog from the mid-70's with full listings. You might have
greater luck finding replacements by specifying the manufacturer & type
number.
If the switch is an unusual pole arrangement or pin-type (PCB mount
rather than wire eyelets) and the body of the switch is still present,
it is sometimes possible to rebuild such switches with the toggle from
a surplus one of more-common type.
4 p.m.
On 2010 Aug 1, at 12:14 PM, Brent Hilpert wrote:
On 2010 Aug 1, at 9:24 AM, Jay West wrote:
(Sorry, looking at your message again I see you were asking for the
model #'s.)
If they are C&K switches:
http://www.ck-components.com/product-matrix,21144,en.html
probably in the 7000 series, apparently they are still available:
http://www.ck-components.com/7000/toggle,10598,en.html
The full catalog is there under "Download 7000 catalog pages". A
bazillion options.
First on my bench will be a bunch (8 or so) of
Data General 800/1200
machines and a few Nova 2's. I can think of several questions so far
to get me started down the path:
1) A number of the 1200 machines have broken front panel toggle
switches (the switch handle was broken off and lost). Some are spring
return to center, some are just two position. Before I take the
approach of robbing one of the machines for front panel switches, is
there someplace that I can purchase exactly idential (both
electrically and cosmetically) switches, or does some one have donor
switches available for trade? I am a stickler for completely
identical parts, especially for front panel switches :) I was hoping
someone had been down this road before and knew the switch model #'s,
etc.
Jay, is this the front panel in the first picture on the wikipedia
page?
http://en.wikipedia.org/wiki/Data_General_Nova
If those are 'standard size' mini-toggle switches, they may be C&K
switches (typically having a red body).
C&K switches tend to be well-marked with a type number stamped in the
metal, and are fairly prevalent in equipment from the period. I have
their catalog from the mid-70's with full listings. You might have
greater luck finding replacements by specifying the manufacturer &
type number. 
5:23 p.m.
New subject: M20 Olivetti on German eBay
Hi
For anyone that might be interested, there is an M20 up for auction
on the German eBay.
These are not your normal PC. They used a Z8000 processor instead
of the X86. It needs some repair and a monitor but is still a cool machine.
The monitor is a little tricky but I'm told an M24 monitor can be wired to
work.
I have two of these in my collection and I have one working with a hard
disk. I've got both PCOS and CP/M-8000 working on mine.
Dwight
6:37 p.m.
Brent wrote...
Jay, is this the front panel in the first picture on
the wikipedia page?
http://en.wikipedia.org/wiki/Data_General_Nova
Yep, that's the ones.
If those are 'standard size' mini-toggle
switches, they may be C&K
switches (typically having a red body).
Oh, I'm sure they are C&K... I was
just hoping someone already knew the
correct part number for the identical switches :)
J
2 Aug
2 Aug
10:55 a.m.
Jay West wrote:
2) I have quite a number (maybe around six or seven)
of rackmount
dual cassette tape units for these machines. I seem to recall that
they use cassette tapes that are not identical to the standard common
audio cassettes available today. Is anyone aware of where these
special tapes can be purchased new?
Would not the tapes used for the C64 be the same?
All the other tapes I can think of is for audio, not digital
recording. If you do find tapes it would be a box of 24 or
so in some warehouse.
Ben.
11:12 a.m.
On Aug 2, 2010, at 16:55, Ben wrote:
Jay West wrote:
No, not the same. C64, like pretty much every other 1980's home
computer, used plain (Type I, ferro) audio cassettes; but I distinctly
remember seeing tape streamer tapes listed in catalogues with the same
mechanical characteristics as audio cassettes, bar for a cutout in the
center of the long, narrower side of the housing. This presumably to
prevent regular audio cassettes from being used in the tape drives.
I'd assume they had at least different magnetic properties, if not
minor mechanical differences, too.
.tsooJ
2) I have quite a number (maybe around six or
seven) of rackmount
dual cassette tape units for these machines. I seem to recall that
they use cassette tapes that are not identical to the standard common
audio cassettes available today. Is anyone aware of where these
special tapes can be purchased new?
Would not the tapes used for the C64 be the same?
All the other tapes I can think of is for audio, not digital
recording. If you do find tapes it would be a box of 24 or
so in some warehouse. 
11:59 a.m.
Joost van de Griek wrote:
No, not the same. C64, like pretty much every other
1980's home
computer, used plain (Type I, ferro) audio cassettes; but I distinctly
remember seeing tape streamer tapes listed in catalogues with the same
mechanical characteristics as audio cassettes, bar for a cutout in the
center of the long, narrower side of the housing. This presumably to
prevent regular audio cassettes from being used in the tape drives. I'd
assume they had at least different magnetic properties, if not minor
mechanical differences, too.
With my Sinclair, I've been using a midrange home stereo tape deck to
store data. The deck has bias settings for ferrous, chromium dioxide
and metal tapes. I've had distinctly better luck with data lifetimes on
metal cassettes.
Peace... Sridhar
2:32 p.m.
No, not the same. C64, like pretty much every other
1980's home
computer, used plain (Type I, ferro) audio cassettes; but I distinctly
remember seeing tape streamer tapes listed in catalogues with the same
mechanical characteristics as audio cassettes, bar for a cutout in the
center of the long, narrower side of the housing. This presumably to
prevent regular audio cassettes from being used in the tape drives.
I'd assume they had at least different magnetic properties, if not
minor mechanical differences, too.
AFAIK apart from that notch, they are mechanically the same -- same
positieond of spools, capstan holes, head access hole, etc. Same design
of spool/hub. Same position of the write-protect hole. I don't think
there were any mirros for optical sensorts in the data cassetes either,
but they may well have detected the clear leader by reflecitons off the
cassette shell, so only light-coloured cassettes would work.
-tony
8:03 p.m.
On 2 August 2010 20:32, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
AFAIK apart from that notch, they are mechanically the
same -- same
positieond of spools, capstan holes, head access hole, etc. Same design
of spool/hub. Same position of the write-protect hole. I don't think
there were any mirros for optical sensorts in the data cassetes either,
but they may well have detected the clear leader by reflecitons off the
cassette shell, so only light-coloured cassettes would work.
Well, I've definitely seen black streamer cassettes (being offered).
What I meant was, they might have been engineered to a higher standard
than your average audio cassette.
.tsooJ
10:16 p.m.
On 8/2/10 5:03 PM, "Joost van de Griek" <gyorpb at gmail.com> wrote:
On 2 August 2010 20:32, Tony Duell <ard at
p850ug1.demon.co.uk> wrote:
/me hangs head in shame...
About 20 years ago I had a bunch of audio recorded on old data cassettes and
gave them all away about 10 years ago.
AFAIK apart from that notch, they are
mechanically the same -- same
positieond of spools, capstan holes, head access hole, etc. Same design
of spool/hub. Same position of the write-protect hole. I don't think
there were any mirros for optical sensorts in the data cassetes either,
but they may well have detected the clear leader by reflecitons off the
cassette shell, so only light-coloured cassettes would work.
Well, I've definitely seen black streamer cassettes (being offered).
What I meant was, they might have been engineered to a higher standard
than your average audio cassette.
.tsooJ
3 Aug
3 Aug
5:43 p.m.
New subject: DG 800/1200 questions - data cassettes
I have bought data cassette tapes for an NCR digital tape unit on Ebay.
From this guy:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=180535980883&ssP…
About 30 cents each or so. I don't know if this is the type that the DG systems need
or not.
Bob
--- On Mon, 8/2/10, Geoffrey Reed <geoffr at zipcon.net> wrote:
From: Geoffrey Reed <geoffr at zipcon.net>
Subject: Re: DG 800/1200 questions
To: "cctalk" <cctalk at classiccmp.org>, "Joost van de Griek"
<gyorpb at gmail.com>
Date: Monday, August 2, 2010, 7:16 PM
On 8/2/10 5:03 PM, "Joost van de
Griek" <gyorpb at gmail.com>
wrote:
On 2 August 2010 20:32, Tony Duell <ard at
p850ug1.demon.co.uk>
wrote:
> AFAIK apart from that notch, they are mechanically
the same -- same
> positieond of spools, capstan holes, head
access
hole, etc. Same design
> of spool/hub. Same position of the
write-protect
hole. I don't think
> there were any mirros for optical sensorts in
the
data cassetes either,
> but they may well have detected the clear
leader
by reflecitons off the
> cassette shell, so only light-coloured
cassettes
would work.
Well, I've definitely seen black streamer cassettes
(being offered).
What I meant was, they might have been engineered
to a
higher standard
than your average audio cassette.
.tsooJ
/me hangs head in shame...
About 20 years ago I had a bunch of audio recorded on old
data cassettes and
gave them all away about 10 years ago.
5100
days inactive
5104
days old
30 comments
18 participants
participants (18)
-
aek＠bitsavers.org -
ard＠p850ug1.demon.co.uk -
bfranchuk＠jetnet.ab.ca -
bobalan＠sbcglobal.net -
cc＠informatik.uni-stuttgart.de -
cclist＠sydex.com -
dkelvey＠hotmail.com -
geoffr＠zipcon.net -
gyorpb＠gmail.com -
hachti＠hachti.de -
henk.gooijen＠hotmail.com -
hilpert＠cs.ubc.ca -
jwest＠classiccmp.org -
nico＠farumdata.dk -
pat＠computer-refuge.org -
ploopster＠gmail.com -
pu1bzz.listas＠gmail.com -
schoedel＠kw.igs.net