> Date: Tue, 9 Apr 2013 17:04:30 -0700 (PDT)
> From: Brian Roth <abacos_98 at yahoo.com>
> To: ClassicCmp <cctalk at classiccmp.org>
> Subject: H780 power supply
> Message-ID:
> <1365552270.75693.YahooMailNeo at web141403.mail.bf1.yahoo.com>
> Content-Type: text/plain; charset=us-ascii
>
> Started tearing into the 11/780 and pulled the 11/03 and the RX01 out to clean and test. Looks like the PS is bad in the 11/03. It powers on and the fans run because they are AC but I am getting sometimes 4.5 volts on the 5v line and 0 volts on the 12v. I have 34 volts coming out of the diode rectifier. I suspect switching transistors.
>
First, if it has Molex/AMP Mate-n-Lock connectors, check them for bad
contact.
DEC loved these during the PDP-11 era, and I had a constant battle with our
used 11/44 to keep it running. The contacts would develop an oxide
film, run
hot and eventually burn up the contacts, connectors, wire, etc. Especially
with fluctuating output, that soulds very much like poor contacts.
I never tore the LSI-11 apart on a 780, so I don't know what the PS
looked like, but I would bet there are some of those AMP connectors in
it with the crummy tin plating.
Jon
>>> I know I've asked about this in the past, butI figured I'd try again:
>>> Anyone have any idea where to track down ROMs for the Grid Compass I or
>>> II (1101 / 1129)? I accidentally formatted my 1129's internal bubble
>>> memory tonight (while intending to format an external floppy) and now of
>>> course it won't boot. (Doesn't seem to want to try booting from the
>>> floppy drive either, unless there's a magical keysequence...)
>> According to the manual:
>>
>> "To load the operating system from Floppy Disk or Portable Floppy, turn
>> on the computer while holding down the F (for Floppy Disk) key.
>>
>> If both a floppy disk and a portable floppy are attached to your computer
>> and you want to start up from the portable floppy, open the door to the
>> floppy disk drive before turning on the computer."
>>
>> You can also use 'H' to force a boot from a hard drive, otherwise it
>> boots from configured primary storage which is usually Bubble.
>
>Excellent -- it looks like I'm up and running again. Thanks! I don't
>suppose that manual you're referring to has been scanned? I have yet to
>find a copy of the user's manual in any form and it'd be nice to have a
>copy...
Glad it worked out!
Unfortunately the manual that I have is probably not what you are looking
for. it is entitled "GRID Management Tools Reference" (1984) and is mainly
about the GRID user software. It does have a "System Basics" section which
is where I found the information about booting from floppy.
This is quite a thick binder - It would take me some time to scan it, and
I honestly don't see having the available time to scan all of it in the near
future, however I could work away at it slowly...
FYI, the sections are named:
System Basics
GRiDmanager
Common Commands
GRiDFile Database
GRiDPlan Worksheets
GRiDPlot Graphics
GRiDWrite (Part 1) Text Editing
GRiDWrite (Part 2) Text Formatting
Error Messages
Appendices
Glossary
Index
GRiDVT100/GRiDReformat
It also includes original GRiD disks for:
GRiD-OS 3.1.0 A
GRiD Management Tools 3.1.0
GRiDVT100/GRiDReformat 3.1.5
Images of these disks are already available on my site.
Dave
--
dave13 (at) Dave Dunfield
dunfield System/Firmware development services: www.dunfield.com
(dot) com Classic computers: http://www.classiccmp.org/dunfield
Date: Sun, 7 Apr 2013 11:13:42 +0100
From: Colin Eby <colineby at isallthat.com>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Subject: Re: 9-track alignment (skew) tapes for R/W-head adjustment
Message-ID: <B5214C89-7571-4779-B1BC-9DB00FF5B119 at isallthat.com>
Content-Type: text/plain; charset=iso-8859-1
Jon,
First, lemme reassert my non-expert status on this.
However, my understanding of PE -- phase encoding as a raw signal --
is that a 0 is a low to high transition(Thomas or reversed high to
low for IEEE) against a fixed clock time. Successive 0s have to be
encoded taking the sign low to high, before going high to low again.
The system is to ignore those signals and simply count the
transition at the mid-point of the period. Setting the blocking
aside, doesn't that mean you end up with two transitions in a period
for every zero. And if you write zero to every channel you get a
nice sine wave at the pre-amp, with the parity bit being the inverse
signal (all ones).
NZRI would of course be rather different. But for PE, this is my
understand of the signal inside a block. I believe that's the signal
form you were thinking of.
OH, you meant to write the tape in 1600 BPI (PE) mode! yes, that would
put 3200
transitions per inch on all data channels, but the parity channel would
have its
transitions out of phase with the data channels. PE mode will write two
transitions for every bit time when the same bit (1 or zero) is written,
but for alternating 1's and zeros, you only get one transition per bit time.
The polarity of the transition at the center of the bit time contains
the data
bit, and additional transition needs to be added when the same data bit
follows. See Page 4-11 of this doc for a picture :
<ftp://bitsavers.informatik.uni-stuttgart.de/pdf/digidata/0551711_1140-1640-1740_2-79.pdf>
Generally, skew is not worried about so much in PE mode, the drives have
FIFOs to resync the data. But, of course after repairing the head
mounting, it
could be WAY off, too far for the FIFO to correct. They usually only have
9 bit times worth of skew correction.
Anyway, most older 800 BPI drives have circuitry built-in to assist in
skew adjustment,
an analog summing circuit that adds the output of the 9 bit detectors
together.
The stepped square wave is very easy to interpret and adjust on a scope.
I've never done skew adjustment on 1600 or 6250, I think it would be
harder than on 800 BPI.
I think the best bet is a digital or storage scope, looking at data channels
4 and 5 (the outermost ones on the tape) on two scope channels, and
triggering
so the first transitions of a block are seen. The preamble is 40 bytes
of all
zeros, then one 1, followed by the data.
Jon
Call me odd, but my absolute, top favorite computer is my MicroVAX in a
BA123 chassis. If the house were burning, that would be the one computer I
would try to retrieve. Sadly, last night, the daughter snapped the corner
off the louvers on the top left of the chassis. Unless some kind sole has a
replacement part, I plan on gluing the pieces back on. My question is,
cyanoacrylate or epoxy?
allison <ajp166 at verizon.net> wrote:
[RX02 or RX50]
> > Mass storage for my system is another area I need to spend more thought on, for now I was planning to stay with the RL drives I got with the case.
> >
> In the PDP11 world its easy to build a system that forgets portable IO.
> A reminder PDP-11 as not a PC and even a 256kb floppy is viable storage
> as RT11 fits on it.
I'm not sure what I'd need it for? There is no other system within walking distance that would understand the floppy format natively.
Any file I/O thus most likely will happen across the Internet (involving a PC anyway), so I hoped I'd be fine with the TU58 emulation software discussed below.
>> RL packs were over 160$ new (...)
> cables, terminators and those annoying and scarce drive ID plugs.
Terminator: check.
ID plugs 0 and 1: check.
Cables: no check yet but inbound.
> If anything the floppy is always a must on my systems as all my diags and
> base RT11 systems are on that media (RX01, RX02, RX50, RX33, RX23).
Are they also available in TU58 (file) format?
> A viable uVAX is more than 150mb, (more like 300-500 for V7),
> a loaded PDP11 is 30MB. Just difference is OS utilization.
So I guess it all boils down on what one wants to run on it.
I've got one functional RD53 in it right now, and a second one I hope to revive at some point in the future.
> I would not covet a large drive unless you had the application that
> required it.
I thought that we here run large drives just for the kicks of it?!
> > I do have a TQK(mumble) board already (which was originally also intended for the VSII), but no drive yet.
> Save it as loading diags from TK50 is both slow and painful assuming the system can boot a tK50 (not guaranteed).
?? (not understanding the above). I should save the controller because the whole subsystem is bad?
[core]
> The older LSI11 systems had it if there was a call for non volatile
> memory, the cost was high.
> I happen to have 16KW of qbus core. Also core had a far slower cycle
> time than Ram of
> the day. Core that ran at 1.5us was fast where ram on the day was
> under 1us and dropping.
So thus probably not very prevalent and not easy to find nowadays. Ho hum.
I've also already found out that the memory board I'll be getting is 512k_Bytes_ (256kW) and does _not_ have BBU support.
[OS question]
> Start with RT11 as a base os and it will allow you to test and get comfortable at lower
> cost to learn. It will be transferable knowledge to RSTS or RSX, may help with getting Unix
> on the machine.
Agreed, sounds like a good starting point.
So long,
Arno
All,
Every couple of years I throw this one out there. Would anyone have a copy of the media for an IBM System/36 5363 -- that the second version of the 5.25" distribution. I'd love to get my hands on a copy if anyone has such a thing, either physically or as an image set.
-Colin
http://www.theregister.co.uk/2013/04/04/gates_allen_reshoot_photo/
?
One of the most iconic photos from the history of Microsoft, featuring
a lanky young Bill Gates perched next to his coding mentor (the way he
tells it) Paul Allen, has been recreated at Seattle's Living Computing
Museum.
[...]
Among the systems still surrounding them are an Apple II with twin
drives and an ancient monitor in the top left of the picture, with a
Commodore Pet below Bill Gates. Readers who can identify the other
systems, please let us know in Comments.
?
--
Liam Proven ? Profile: http://lproven.livejournal.com/profile
Email: lproven at cix.co.uk ? GMail/G+/Twitter/Flickr/Facebook: lproven
MSN: lproven at hotmail.com ? Skype/AIM/Yahoo/LinkedIn: liamproven
Tel: +44 20-8685-0498 ? Cell: +44 7939-087884
It's running! Telnet to 97.86.233.68 to take a look and help me test it.
You can use the standard Windows telnet program, Putty, Linux, or
whatever you have handy.
Around 10 users can be on at the same time. When you sign on (no
password required) there will be a little menu to help you waste some
time. Some things you can do are see who else is on the server, view the
machine type, ROM BIOS date and DOS version, check the TCP/IP statistics
to see how much traffic it is handling, etc.
There are some upgrades since the last time I ran this test (in Dec 2007):
- The TCP/IP stack is much better
- I'm doing 'telnet' negotiation to figure out the terminal type, turn
echoing on, etc
- Crude line editing has been added
Right now it is running on my PCjr using a Xircom PE3 10BT. I plan to
leave it up as long as it runs, or three days, whichever comes first. It
is a PCjr so if there is a momentary delay, don't panic - it's probably
just doing disk I/O.
Backspace is a little dodgy .. it really wants ASCII 8 and a lot of
terminals and emulators do ASCII 127 instead. Try variations with the
shift and control keys if it doesn't work.
Thanks,
Mike
Some things are easy to Google, and you get reasonably appropriate results.
Other things give you whacky results!
Google HP 700/96, and you get decent results.
Google apple, and the first 20 items relate to Apple computers or Apple
Corp., not to eating apples.
Google Commodore, and surprisingly, the first line is not Commodore computer
related. (Interestingly, it seems a company has bought the rights to the
Commodore and Amiga names, and will be re-inventing the C64 with nVidia
graphics inside)
Google wolf cub, and you get everything from animals to Scouting to music to
golf clubs!
Seems like they need to tweak their algorithms again?
_____
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3267 / Virus Database: 3162/6224 - Release Date: 04/04/13
Hi there,
has someone a technical documentation for the PSU of the TSZ07 9 Track
tape drive?
My PSU is working but some parts are overheating when the drive is in
standby mode where no FAN is running.
In the technical manual for the TSZ07 from manx for example are no details,
only the replacement procedure is described.
.. or has anyone one to sell for small money (prefered in europe because
of the shipping costs..)
There are shopts that want to sell HP/Compaq/DEC 29-28461-01 fpr $200 and
more... thats to much.
Regards,
Holm
--
Technik Service u. Handel Tiffe, www.tsht.de, Holm Tiffe,
Freiberger Stra?e 42, 09600 Obersch?na, USt-Id: DE253710583
www.tsht.de, info at tsht.de, Fax +49 3731 74200, Mobil: 0172 8790 741
