Can anyone tell me anything about the subject: line? It seems to be a high-end graphics terminal from the
mid 1970s. I have found the electronics unit while unpacking here, I think I have the keyboard (with a little
built-in joystick?) somewhere too. I don't have the monitor, but I am guessing it's TV rates.
Pysically it's just a metal box (about the size of a 4U rack unit without flanges). There is nothing on the front
panel. The back panel has the on/off switch and connectors for a keyboard (DA15), 'Digital Video' (ditto),
Host and Downstream RS232 ports (DB25, of course) Host and Dowstream current loop ports (DE9), 3 video
outputs (BNC, I assume these can be used as R,G,B), mix video output (ditto) and video input (my guess is that
the terminal video can be overlayed on some other video signal, again a BNC).
The top cover comes off with 2 screws. It reveals very little apart from a massive linear PSU. The interesting
stuff is exposed by removing the front panel (4 screws) which gives access to the card cage. There are 2
columns of half-width cards at the top, then about 7 full width ones. 2 of the half-width cards are wire-wrapped
not PCBs. I forget what they do, one of them seems to be the video timing/sync counters. On other half-width
cards are the processor (6800), ROMs (lots of EPROMs),Comms, video output (resistor DACs, etc) and
a 'vector generator' which I guess is to draw lines, it's just a lot of of logic ICs, no microprocessor.
One of the full-width cards is something like 'area fill'. So it does that in hardware too? The others -- and there
are half a dozen of them -- are 'Pixel Store'. Each has 16K*16 of DRAM and a 16 bit ALU (4 off 74181).
I hate to think how much this cost when new. RAM and ALUs were not cheap!
-tony
Hello fellow DEC enthusiasts,
I have a BA11-N mounting box with Q18 9-slot quad-height backplane. The
power supply is toast. My goal is to hack it into something useful.
I'd like to replace the power supply with a sufficiently-powered ATX PSU.
I've read the instructions at:
http://www.diane-neisius.de/pdp11/index_E.html#atx
However, unlike the DEC PSU, the ATX power supply won't supply a 60 Hz line
time clock (LTC) signal to the backplane via BEVENT. So, my question - has
anyone used a standard ATX PSU for a PDP-11 QBUS system, and if so, how'd
you work around the LTC issue?
Once I solve the power issue, I have 11/23 CPU cards, RAM, and SLUs galore.
I'm not planning to make this very power hungry though.
Thanks!
- Earl
I?m wondering if anyone has seen something like this:
You input text. The program converts the text into what it would sound like if it were being transmitted at 300 baud which you can then save.
Oh, I imagine that, say, I dunno, some kind of 300 baud modem could do this, but I don?t have such a beast. I wondered if someone may have created such an item as a programming exercise.?
Cheers,
m
>
> > From: B Degnan
>
> > Yes, steady voltage
>
> I think Tony meant 'did you look at it with a 'scope'... :-)
>
> Noel
I used two different scopes and a Fluke meter that can capture MIN/MAX.
It's a nice steady flow as far as I can tell. The min/max is in the
hundredths place, there is no major ripple.
Bill
On 06/03/15 9:40 AM, Mouse wrote:
>>>> one other, which you may or may not classify as a ?language?, is
>>>> Mathematica.
>>> I don't know enough about it to offer an opinion [...]
>> I've been using Mathematica for years. [...] I've also used MatLab
>> which also falls somewhat into that category. MatLab is is really
>> optimized around vectors and arrays.
>
> That might be more similar to APL, then.
>
> This has been rattling around in my mind for a little while now and I
> think one reason I didn't think of things like Mathematica or Matlab is
> that they're single-implementation. ...
>
> /~\ The ASCII Mouse
> \ / Ribbon Campaign
> X Against HTML mouse at rodents-montreal.org
> / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B
>
As I haven't yet seen it mentioned in this discussion, I think I need to toss in Scilab (http://www.scilab.org/ , also on WP), which is a Matlab workalike that came out of a French mathematical research iInstitute (INRIA, Institute Institut national de recherche en informatique et en automatique). It is under a GPL compatible license (CeCILL) and should therefore also work for those of us for whom free beer isn't free enough :) I used it^w a tiny portion of it during my student thesis for predicting and comparing the EMI spectra of phase and burst fired power controllers under different load conditions and power settings.
So Long,
Arno
This was a screen driver I'd written to do pseudo windowing on green
screen terminals. I thought it would have made more sense and been
cleaner in C, but it wasn't.
On 2/17/2015 9:27 PM, Mouse wrote:
>> I've rewritten cobol into C a few times when I was a big enthusiast
>> of C and the C code was longer and harder to maintain.
>>
> That is no surprise to me. If you were to take code written in C and
> translate it into COBOL, I'd generally expect the COBOL code to be
> longer and harder to maintain, too.
>
> Indeed, I'd expect that for pretty much any pair of languages;
> translating code out of the idiom it was written for generally makes it
> larger and harder to understand.
>
> /~\ The ASCII Mouse
> \ / Ribbon Campaign
> X Against HTML mouse at rodents-montreal.org
> / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B
>
>
Working on PDP 11/40, issues with DC LO and AC LO
The front panel confirms a DC LO issue, CONS and RUN lights are off, BUS
and PROC lights are on. The panel is unresponsive.
With the cable removed from the h742a connector, P9 says DC LO and AC LO
are 3.53v, which is lower than the expected +4.8v. This tells me there is
a fault in the h742a. I hate to remove the 742a power control board but I
finally have the machine in my basement so I can work on it for an extended
period. Voltages of the other regulators are OK. I think it's conclusive
that the h742a has a fault to be repaired.
Next, I re-connected the cable to P9. The DC LO and AC LO wires lead to
J18, which feeds DC LO and AC LO to the backplane on my system. Reading
>from J18 the DC LO value remains at 3.53v, but the AC LO drops further to
1.72v. I get similar readings from the backplane pins themselves.
When I remove the Status Module card (M7235) from the backplane the AC LO
on J18 jumps up to 3.53v - i.e. AC LO jumps back to origination levels.
Question - Is there is *also* a potential fault in the M7235 circuit
related to AC LO, -OR- is it normal for the M7235 to detect and pull down
AC LO further forcing the system to halt? I am working to understand the
circuits from page 120 of the KD11-A Maint manual
http://bitsavers.trailing-edge.com/pdf/dec/pdp11/1140/KD11-A_Maint.pdf
My plan is to repair the h742a first and see how it goes, but I'd like a
2nd opinion if anyone has one, regarding the M7235....thanks!
photos
http://vintagecomputer.net/browse_thread_record.cfm?id=178&tid=8
Bill
I have a box of old HP paper tapes to read, and am having an awful time
trying to build the right serial cable to connect a GNT-4601 reader/punch
to a Linux PC. Does anyone have a known good cable diagram and stty
settings that will work? Thank.
Mike Loewen mloewen at cpumagic.scol.pa.us
Old Technology http://q7.neurotica.com/Oldtech/
