>
>Just in case anyone is interested, replacing the failed Darlington
>transistor fixed the problem. The RD53 now spins the disk again. Thanks to
>everyone who helped.
>
Some people enjoy repairing things. I find it a bit of a drudge.
What I enjoy is the feeling of satisfaction when a repair succeeds :-)
Well done to all involved.
I am now looking with renewed interest at my pile of doorstops which once spun.
Regards,
Peter Coghlan.
I acquired an RD53 disk recently. I have just been trying it out. The heads
were stuck, as usual, but the main thing is that the disk itself will not
rotate. The locking mechanism that keeps the heads parked releases on power
up but that is all that happens.
I have not come across this particular kind of failure before, does anyone
have any suggestions for common causes of this kind of failure?
Regards
Rob
>
>The Terminals Wiki is open for public browsing!
><http://terminals.classiccmp.org/wiki/index.php/Main_Page>
>
>This is a joint project between myself (username Legalize),
>Jason T (username Silent700) and Ian Primus (username Sark).
>I am the wiki administrator.
>
>My intention was to create a single reference site for everything we
>can find about terminals.
>
Well done - this looks like it will be a useful reference point.
I have a user guide for an ICL model 6402 Character Display Terminal which
I used in 1988. It may be compatible with a Televideo 950 (or maybe 925). I
only used it as a fairly basic terminal but IIRC it seemed to have an endless
number of features that I never felt the need to use. I only have the manual,
not the terminal. If someone has the terminal and not the manual, I would be
happy to give them the manual or scan it for them.
I am looking for a maintenance manual for a Lear Siegler ADM-5. I found
the manual for the ADM-3A on bitsavers (thanks Al!) and this helped me to
fix one of my ADM-5 terminals but my other one has a fault that I think is
in an area with significant differences to the ADM-3A.
Regards,
Peter Coghlan.
Frankly, IBM terminal land is completely unknown to me. I am looking
for a volunteer to contribute information about terminals from IBM and
other manufacturers that were intended for the IBM mainframe world.
Let me know if you're interested! The pay is nonexistent and it's
entirely a labor of love on your part, but I think we're off to a good
start. However, the wiki is almost completely lacking on IBM
mainframe type terminals.
--
"The Direct3D Graphics Pipeline" -- DirectX 9 version available for download
<http://legalizeadulthood.wordpress.com/the-direct3d-graphics-pipeline/>
Legalize Adulthood! <http://legalizeadulthood.wordpress.com>
>
>Its a X25 Packet/Assembler/Dissasembler. It allows ordinary Async
>Terminals to be connected to an X.25 network. In the UK all Universities
>had such networks under the umbrella of JANET. Some at Janet probably
>has a manual. I have forgotten almost every thing I know about them. I
>have asked one of my former colleagues if he has any info.
>
These were also to be found in Irish Universities where early networking
was also X.25 based.
I have a small stash of X.25 capable kit which I have no real interest in.
It is available for free to anyone interested and is located in Dublin, Ireland.
I would prefer collection but will consider shipping if someone is really keen.
Among the bits and pieces are two Satelcom X.25 switches. Both are marked
MegaPAC E but they are different sizes. Also a DEC DEMSA and two DEMSB X.25
routers (manufactured in DEC's former facility in Clonmel, Ireland) and some
cables.
And the connection with this thread? The DEMSA has a sticker on one of the
ports which says "Camtec".
Regards,
Peter Coghlan.
On Wed, 11 Apr 2012 09:23:49 +0100, "Rob Jarratt"
<robert.jarratt at ntlworld.com> wrote:
>
> I need to replace a transistor in my H7140 PSU for my PDP11/24. The
> transistor is marked GPSA55J3 and the printset identifies it as "XA
> 55 PNP
> 500MW SI 60 50 P", it is in a TO-92 package. I have tried to find
> specs for
> an A55 and can only find partial matches, so I am not sure what
> today's
> equivalent would be. Can anyone help me work out what the equivalent
> today
> would be?
>
> Thanks
>
> Rob
Sounds like a 60V, 500mW device. BC556, MPSA-56. A BC161 might also
work, except it is in a TO-39 case, or a 2N2907 in a TO-18 case.
Looking at the printset on vt100.net, none of the A55 transistors
appear to be doing anything terribly demanding, so any of the above
ought to work.
/Jonas
>
>There are orher problems now with that VIM Source, the files blowfish.c and
>sha356.c take very very much time to compile. I do have an account on
>Vaxmans VAX7000/820 and even on this machine the compiling was not done after
>13hrs of CPU Time. SHA356.c behaves pretty much similar.
>I'll look later this day if the compiling gets done on this machine, on my
>VS4000 the same process is running now for 12hrs on the CPU and the
>VS4000/90 isn't the slowest VAX so far as I know...
>
Well, my curiosity got the better of me. I downloaded VIM73-69 for VMS and
attempted to compile blowfish.c on my VAX 4000/100A with VAX/VMS 7.1 and
DECC V6.4-005. I don't have MMS or MMK installed so I had to hack a little to
make it work.
I found that after some seconds work, the compiler went into a CPU bound loop
and seemingly did nothing useful after that (unless it is thinking hard and
will come up with something useful some time from now!).
The source is not large so I was able to find that the part that the compiler
was having difficulties with was these two lines of macros in bf_e_block():
F1(0) F2(1) F1(2) F2(3) F1(4) F2(5) F1(6) F2(7)
F1(8) F2(9) F1(10) F2(11) F1(12) F2(13) F1(14) F2(15)
I found that if I commented out F1(10) F2(11) F1(12) F2(13) F1(14) F2(15)
the compile would complete in just under a minute.
Next I tried commenting out just F2(11) F1(12) F2(13) F1(14) F2(15)
and then the compile completed in around 7 minutes. It took about the same time
if I only commented out F1(12) F2(13) F1(14) F2(15).
If I commented only F2(13) F1(14) F2(15) the compile took nearly two hours!
Finally, it dawned on me to try compiling the original code with /NOOPTIMISE
and this completed in 30 seconds!
So, it appears that something in those two lines is causing the optimiser to
spend way too much time doing something.
At least the good news is that if you compile blowfish.c (and perhaps sha356.c)
without optimisation, it should be possible to get it done in a reasonable
amount of time. Maybe the compile you are currently running will also complete
eventually.
Regards,
Peter Coghlan.
On Tue, Apr 10, 2012 at 12:58 PM, Bill Sudbrink <wh.sudbrink at verizon.net> wrote:
> ? Interesting that one of your partners goes by Silent700
> ? but there are no Texas Instruments terminals in your wiki
> ? yet. ?If you're interested, I'm going to be bringing one
> ? of the last variants of the 700 to VCF East next month to
> ? use as a printing terminal on my SWTPc.
Yeah yeah.....it's all In the Works, Check's in the Mail, Real Soon
Now. Richard probably has more S700s than I do, anyway ;)
Seriously, though, Richard has done a ton of work on this, from
wrangling his own voluminous collection to deciphering the WikiSpeak
necessary to make this a pro job. I look forward to contributing!
-j
--
(Real Soon Now)
Greetings;
Long-story-short, a couple of years ago I picked up six Onyx2 racks and
have been moving them around with me without ever actually firing them up.
I've finally got myself sorted and have been slowly working through
bringing things up and having some successes, but every step closer has me
finding a new problem.
My set-up right now has one graphics head and five compute nodes cabled
together in a daisy-chain (not enough CrayLinks for anything else). It
appears all but one of the MMSCs are shot, so I'm doing manual start-ups
using the keys.
My current confusion is how to nominate which system becomes the Global
Master. For some odd reason whenever I bring up three racks the machine
I've "picked" as the master (keyboard/mouse/gfx head) comes up just fine
and boots into IRIX, but whenever I add two more nodes things get a bit
more fuzzy and the Global Master appears to migrate around.
I had initially believed that the last rack in the power-up sequence would
always become the Global Master, since it goes and finds all the rest, but
this apparently is not the case... or perhaps there are corollaries I'm
unaware of.
The more times I turn this thing on and off the more hardware is failing
on me, not unexpectedly. I've lost a PSU, a node board and now one of the
racks has started making a worryingly hot-electrical smell. I'd really
like to get it all working together just once before I get old and grey.
Cheers;
- JP
>
>I have cleared this in the meantime with some help of B. Ulmann aka vaxman.
>The paging file was much to small, I've diabled swapping and created a
>much bigger pagefile.sys (500000 blocks), raised PGFLQUOTA to 130000 blocks
>and some other things. The compiling doesn't stop now anymore because of
>vm-space outage.
>
I'm glad the original problem is solved.
>
>There are orher problems now with that VIM Source, the files blowfish.c and
>sha356.c take very very much time to compile. I do have an account on
>Vaxmans VAX7000/820 and even on this machine the compiling was not done after
>13hrs of CPU Time. SHA356.c behaves pretty much similar.
>I'll look later this day if the compiling gets done on this machine, on my
>VS4000 the same process is running now for 12hrs on the CPU and the
>VS4000/90 isn't the slowest VAX so far as I know...
>
You can check what the compiler is doing with the command:
$ SHOW PROCESS /CONTINUOUS /ID=xxxxxxxx
where xxxxxxxx is the process id of the process doing the compile.
You can also use MONITOR to see what the whole machine is doing.
$ MONITOR MODES
will tell you which processor modes are in use most. If it shows mostly user
mode, the compile is CPU bound. If it shows mostly kernel mode or interrupt
stack, there is an i/o bottleneck. If it shows mostly idle, something is wrong
and the compiler is not getting sufficient access to the machines resources.
$ MONITOR PROCESSES /TOPCPU
should show the compiling process as getting most of the CPU. If something else
is getting a significant amount of CPU, there may be something wrong.
I've compiled a fair amount of C on my VAX 4000/100A which is also pretty fast
and on my VAX 3100 model 76 which is less fast and I don't remember any single
source file taking anything like even 1 hour to compile. Are the sources
involved particularly large or complex? Does the compile show any signs of
making progress (for instance, is the object file or listing file growing in
size) or could it be stuck in a loop doing nothing useful? Is there too much
detail being logged in the listing file resulting in a huge listing output?
You haven't said whether you did an AUTOGEN or not. If you have not, I would
suggest doing one as this should help sort out any other system parameters
that might be incorrect.
>
>I'll report later what happens..
>
I'd certainly be interested to know what's going on.
Regards,
Peter Coghlan.
