Re: File recovery help needed (Alabama)

[Mike Loewen via cctalk]

On Thu, 22 Jun 2017, Mike Loewen via cctalk wrote:

  I was contacted by a faculty member at the University of Alabama 
(Tuscaloosa) who is looking for help in recovering files from some 5-1/4" 
diskettes.  The diskettes are from the 1989-1892 time frame, and most likely 
contain WordPerfect files.  If there's anyone in the area who would be 
willing to help, contact me off-list and I'll put you in touch with him.


   Thanks to all who responded to my help request.  We have it covered.


Mike Loewen mloe...@cpumagic.scol.pa.us
Old Technology  http://q7.neurotica.com/Oldtech/

Re: DECstation 220 - Out of Ideas?

[Ian S. King via cctalk]

On Sat, Jun 24, 2017 at 4:17 PM, Rob Jarratt via cctalk <
cctalk@classiccmp.org> wrote:

> As I mentioned in an earlier email, I have been trying to fix a DECstation
> 220. I have made what I think may be some progress, but I am out of ideas
> now.
>
>
>
> The problem appears to be that the 80286 CPU is shutting down and then the
> Olivetti chip is RESETting it repeatedly. The reason for this seems to be
> that it is failing to read the ROMs. The ROM is an ST M27512. The output
> enable signal (active low) does not appear to go below about 1.8V, although
> it does go up to 5V. It is as if the system is trying to read the ROM, but
> somehow the signal is not going low enough to actually make the ROM read.
> The signal is connected to DMAMEMR (DMA Memory Read) on a Chips P82C206
> controller, and to something on the Olivetti GA099-B, it may be connected
> to
> other components too, but I have not discovered any more so far. I have
> taken the ROMs out and read them in a reader, they seem to read back OK, so
> I don't think they are faulty.
>
>
>
> I am not sure what could cause the signal not to go low enough, apart from
> a
> bad P82C206 or a bad GA099-B. Does anyone have any suggestions or
> experience
> of common causes?
>
>
>
> Thanks
>
>
>
> Rob
>
> I don't recall from this thread - do you have prints?  I'd try to divine
whether this is a wire-OR bus (likely).  If so, I'd suspect the P82C206.
It may not be toast itself - be sure it has sufficient power to drive the
OC transistor that's bringing down the bus, and that its connection to that
bus doesn't have excessive resistance, and that its ground (earth)
connection is also low-resistance.  A long shot: it could be something else
on that bus that's sourcing rather than sinking, but the scenario seems
unlikely.

I'd agree that it's probably not the ROMs, from the symptoms you're
describing - unless, again, one of them has an internal short/leak to rail
on its read-enable pin.  A thought: can you measure the current and its
direction on the P82C206 pin?

That's my troubleshooting thinking given that I don't have it in front of
me.  :-)  I hope this is helpful -- Ian


-- 
Ian S. King, MSIS, MSCS, Ph.D. Candidate
The Information School 
Dissertation: "Why the Conversation Mattered: Constructing a Sociotechnical
Narrative Through a Design Lens

Archivist, Voices From the Rwanda Tribunal 
Value Sensitive Design Research Lab 

University of Washington

There is an old Vulcan saying: "Only Nixon could go to China."

DECstation 220 - Out of Ideas?

[Rob Jarratt via cctalk]

As I mentioned in an earlier email, I have been trying to fix a DECstation
220. I have made what I think may be some progress, but I am out of ideas
now.

 

The problem appears to be that the 80286 CPU is shutting down and then the
Olivetti chip is RESETting it repeatedly. The reason for this seems to be
that it is failing to read the ROMs. The ROM is an ST M27512. The output
enable signal (active low) does not appear to go below about 1.8V, although
it does go up to 5V. It is as if the system is trying to read the ROM, but
somehow the signal is not going low enough to actually make the ROM read.
The signal is connected to DMAMEMR (DMA Memory Read) on a Chips P82C206
controller, and to something on the Olivetti GA099-B, it may be connected to
other components too, but I have not discovered any more so far. I have
taken the ROMs out and read them in a reader, they seem to read back OK, so
I don't think they are faulty.

 

I am not sure what could cause the signal not to go low enough, apart from a
bad P82C206 or a bad GA099-B. Does anyone have any suggestions or experience
of common causes?

 

Thanks

 

Rob

RE: File recovery help needed (Alabama)

[Fred Cisin via cctalk]

Yes.  External 5.25" drives, both 360K and 1.2M were available for the
PS/2 line.   It was just a matter of power and signal cabling to put
together your own.
There was a bracket with a DC-37.  That could be used for PC external
drive, if that was what you had on hand.  Or wanted to connect an 8"


On Sat, 24 Jun 2017, Bill Gunshannon via cctalk wrote:

The only ones I remember were third-party.  SYSGEN comes immediately
to mind.


I had a few IBM ones. (from Foothill College fleamarket)
Beige, rounded corners, round cable
The 360K ones had an asterisk embossed on the faceplate.


Once IBM realized that 360K and 1.2M drives looked the same, they started 
putting that asterisk on the 360K half-height face plates.  That way, if 
you had a drive with no asterisk, then you knew conclusively that it was

A) a 1.2M drive
B) a 360K drive from before the change
C) an aftermarket drive

We thought that putting a marking on the NEW type of drive would have made 
more sense.  Then, at least MOST of the drives could be correctly marked.

RE: File recovery help needed (Alabama)

[Bill Gunshannon via cctalk]

From: cctalk [cctalk-boun...@classiccmp.org] on behalf of Fred Cisin via cctalk 
[cctalk@classiccmp.org]
Sent: Saturday, June 24, 2017 4:37 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: RE: File recovery help needed (Alabama)

>> Let's hope that it's a 1.4M!  If it's 720K, then we could sneaker it
>> to a PS/2 to move it to 2.8M, to take to a NeXT, . . .

On Sat, 24 Jun 2017, Kris Kirby wrote:
> IIRC the PS/2 had a 5.25" drive option in certain form factors.

Yes.  External 5.25" drives, both 360K and 1.2M were available for the
PS/2 line.   It was just a matter of power and signal cabling to put
together your own.
There was a bracket with a DC-37.  That could be used for PC external
drive, if that was what you had on hand.  Or wanted to connect an 8"

___-

The only ones I remember were third-party.  SYSGEN comes immediately
to mind.

bill

Re: File recovery help needed (Alabama)

[Chuck Guzis via cctalk]

On 06/24/2017 01:37 PM, Fred Cisin via cctalk wrote:

> There was a bracket with a DC-37.  That could be used for PC external
> drive, if that was what you had on hand.  Or wanted to connect an 8"

There was also the MCA Diskette Adapter/A, which didn't work with much
"low level" software.

--Chuck

RE: File recovery help needed (Alabama)

[Fred Cisin via cctalk]

Let's hope that it's a 1.4M!  If it's 720K, then we could sneaker it
to a PS/2 to move it to 2.8M, to take to a NeXT, . . .


On Sat, 24 Jun 2017, Kris Kirby wrote:

IIRC the PS/2 had a 5.25" drive option in certain form factors.


Yes.  External 5.25" drives, both 360K and 1.2M were available for the 
PS/2 line.   It was just a matter of power and signal cabling to put 
together your own.
There was a bracket with a DC-37.  That could be used for PC external 
drive, if that was what you had on hand.  Or wanted to connect an 8"

Re: File recovery help needed (Alabama)

[Fred Cisin via cctalk]

He might also need a little hand-holding on how to open the WP files 
with his current word processor

On Sat, 24 Jun 2017, Geoff Oltmans wrote:
There's instructions for opening WordPerfect 5.x and 6.x docs in 
Microsoft Word 2007 on Microsoft's support website, so I imagine that is 
probably not that big of a problem.


Not that big of a problem, nor even any sort of a problem at all.
With a 10 or 15 year old PC, with a 10 or 15 year old copy of Office,
open the file, "SAVE AS".
Most current versions of Open Office no longer support it, so it is 
necessary to install an older version.

I don't know whether the same applies to Microsoft Office.

The client might need help with that, and almost certainly would with 
anything other than USB drive or WWW download.



But, somehow, here, we can turn it into a major project.
(Ed's most recent suggestion of removing an IDE drive merely adds another 
fun step to my multi-step scenario)

Re: DB11-A Bus Repeater Engineering Drawings

[Al Kossow via cctalk]

On 6/24/17 9:14 AM, Noel Chiappa via cctalk wrote:
> So, Paul A lent me a set of these (thanks Paul!) so I could scan them in (they
> are not currently available online).


sigh..

http://bitsavers.org/pdf/dec/unibus/DB11-A_RevS_Engineering_Drawings_Jan76.pdf

which has the schematic
they have been there for over three years

Re: DB11-A Bus Repeater Engineering Drawings

[Al Kossow via cctalk]

They screwed up when they made the maint prints, it's missing from ours as well

I will see if it showed up in the individual module schematic collections, 
though
that will be much more difficult to go through. I scanned binders full of them, 
but
they aren't sorted.


On 6/24/17 9:21 AM, Al Kossow via cctalk wrote:
> 
> 
> On 6/24/17 9:14 AM, Noel Chiappa via cctalk wrote:
> 
>> Does anyone else have a set of these prints?
> 
> 
> http://www.computerhistory.org/collections/catalog/102753063
> 
> i'll try to get to it today
> 
> 

Re: DB11-A Bus Repeater Engineering Drawings

[Al Kossow via cctalk]

On 6/24/17 9:14 AM, Noel Chiappa via cctalk wrote:

> Does anyone else have a set of these prints?


http://www.computerhistory.org/collections/catalog/102753063

i'll try to get to it today

DB11-A Bus Repeater Engineering Drawings

[Noel Chiappa via cctalk]

So, Paul A lent me a set of these (thanks Paul!) so I could scan them in (they
are not currently available online).

Howwever, there's a problem. The last page in the set contains the circuit
diagram for the M7248 BBSY Repeater card (the heart of the whole device, since
the DB11-A uses BBSY to decide which way to turn the repeater on) - and it's
missing. (I have "Page 1 of 2" for the card, but not "2 of 2").

Does anyone else have a set of these prints?

If not, we're not totally hosed: the card has only 7 IC's on it, so it
_should_ be possible to re-create the drawing, working backward from the card,
but it would be nicer to have the original drawing (which might e.g. have
notes on it that would be useful).

  Noel

Datasheet for Olivetti GA099-B?

[Rob Jarratt via cctalk]

I am trying to get a DECstation 220 working again. It looks like the 80286
is being constantly reset. The reset signal seems to come from an Olivetti
GA099-B chip. I have not been able to find a datasheet for this online. Does
anyone have one, or know where I might find one?

 

Thanks

 

Rob

RE: File recovery help needed (Alabama)

[Kris Kirby via cctalk]

On Fri, 23 Jun 2017, Fred Cisin via cctalk wrote:
> Let's hope that it's a 1.4M!  If it's 720K, then we could sneaker it 
> to a PS/2 to move it to 2.8M, to take to a NeXT, . . .

IIRC the PS/2 had a 5.25" drive option in certain form factors.

--
Kris Kirby, KE4AHR
Disinformation Architect, Systems Mangler, & Network Mismanager
Birmingham, AL

Re: File recovery help needed (Alabama)

[Geoff Oltmans via cctalk]

Sent from my iPhone
> On Jun 23, 2017, at 11:19 PM, Fred Cisin via cctalk  
> wrote:
> 
>> On Fri, 23 Jun 2017, Geoff Oltmans wrote:
>> Silly me... And here I was thinking I could just use my dell dimension 
>> celeron machine running win98 complete with 5.25" floppy drive AND (drum 
>> roll) a 10/100 NIC and ftp over to my ftp server. But your idea sounds more 
>> thorough. :)
> 
> Sure.
> But, a 2G USB flash drive will hold the contents of a mighty big stack of 
> floppies (bigger than the hard drive that he had 30 years ago)
> He might find that easier to deal with than ftp.
> 
> He might also need a little hand-holding on how to open the WP files with his 
> current word processor
> 
> 
> --
> Grumpy Ol' Fred ci...@xenosoft.com

There's instructions for opening WordPerfect 5.x and 6.x docs in Microsoft Word 
2007 on Microsoft's support website, so I imagine that is probably not that big 
of a problem.