> From: Allison Parent
> ! Seriously? ... Memory of some form there is a must.
I don't know about you, but my approach in looking into hardware issues is
often to start by reducing things to the simplest possible configuration that
exhibits the failure.
(I asssume the various reasons for that approach are obvious.)
So, the OP couldn't get ODT to work. Well, what's the simplest config one
needs for ODT? Well, a CPU (but it won't be executing any instructions, so one
could leave HALT on), the console serial card (with a working terminal
attached), a bus/backplane to plug them into, and a power supply.
But no, the LSI-11 machines also want memory - although it's unused by ODT
after a single read cycle at power-on.
It's probably worth pointing out that this is _not_ true of the F-11 machines;
those do ODT just fine without memory. Perhaps DEC got some complaints about
the behaviour of the LSI-11, and made a change?
I don't know if the front console on the early UNIBUS machines works without
any memory on the UNIBUS - I'm too lazy to check. I have this vague memory that
they do, though.
> The architecture of pdp-11 has the first 256 words as interrupt vectors
> and software locations.
Some 'internal' interrupts from the CPU (e.g. NXM) are at fixed, low,
locations (in Kernel D space on some of the models with MMU, to be technical -
I don't know about the /40 and /34, etc), but there's nothing that restricts
_device_ interrupts to be in low memory (either physical, or virtual on those
machines which get vectors from Kernel virtual).
E.g. in the "pdp-11 bus handbook" (EB 17525 20), pg. 119, it says "Place
Vector on BDAL <15:00> L" - so one could use 0140000 if one wanted.
Most DEC devices that do the vector with jumpers don't have posts for all 15
bits, it is true, but AFAIK no CPU looks at only the low bits on the bus.
> How else would the console vectors at 60 work.
ODT doesn't use interrupts.
Noel
> From: Brent Hilpert
> I wouldn't have thought any of the (various 11 CPU) ODTs used
> interrupts for the console
They don't.
> Don't know which CPU Noel was referring to.
The OP was having problems with an LSI-11 (M7264 quad card); I was working
with an LSI-11/2 (M7270 dual card - I don't have any LSI-11's). But I'm pretty
sure the CPUs on the two are identical; and certainly, both display the 'must
have memory at 0 for ODT to work'.
Noel
> From: Jonathan (systems_glitch)
> Yep, fun times on LSI-11/2!
Heh, this one was _utterly trivial_ compared to the 'must have working memory
at 0 or ODT won't start'! (I don't think I've ever seen that one in DEC
documentation anywhere...)
Noel
>> Al Kossow via cctalk writes:
>> Buried in a filing cabinet in the basement with a sign that says
>> "Beware of Leopard".
Good one!
> From: Seth J. Morabito
> I'm going to respectfully disagree .. the proliferation of modern
> JavaScript frameworks that are designed to build single-page apps, and
> make the web virtually impossible to scrape or mirror in an efficient
> and simple way. ... every single page is statically generated at
> publishing time and absolutely nothing is dynamic.
It's not clear that it's the dynamic nature of the content he's unhappy with;
it might just be that having stuff scattered across a zillion personal pages
(be they blogs, or whatever) is going to make it hard to find the useful one
when needed, and that's why he's cranky. (Well, more so than he usually
is.... :-)
If it's got something oddball term in the text, a Web indexer might be able
to find it, but what if your search term turns up 17,239 matches? Finding the
useful needle in the hackstack of crap on the current Web is a tall order -
so tall, that I suspect a lot of people don't even try, just shoot off an
email to CCTalk in the hopes that someone here will enlighten them.
I've seen a number of instances recently where people's questions were
answered on the CHWiki, but apparently they couldn't find it. So they
wound up asking here...
Noel
Thanks. I believe you are right also :)
The expensive ceramic packages have hermetic seals, not so the plastic
(epoxy) packages used in commercial grade parts.
There are some kind of failures that can be fixed by baking - but I don't
know if this is one of them (if the bond wire is soldered to the die it
might work). If it detached from the weld at the lead frame, no go. Anyway
there are over 100 chips on the ADM-3A board and I would be more worried
about damaging the others with heat.
I just paid 71 cents for another LS193 ;)
Charles
WB3JOK/0
-----Original Message-----
From: Dave Wade
Sent: Wednesday, August 14, 2019 5:02 AM
To: 'Charles' ; 'General Discussion: On-Topic and Off-Topic Posts'
Subject: RE: ADM-3A question
Charles,
I believe that TTL chips suffer from failure or detachment of the bonding
wire that runs from the die to the interconnect pin, which would result in a
floating pin as described.]
Not sure if environmental storage affects this as chips should be sealed...
I have also recently seen it suggested that heating the chip up in an oven
could affect a temporary repair (sorry I can't find the reference now).
Dave
G4UGM
> -----Original Message-----
> From: cctalk <cctalk-bounces at classiccmp.org> On Behalf Of Charles via
cctalk
> Sent: 14 August 2019 00:20
> To: cctalk digest <cctalk at classiccmp.org>
> Subject: Re: ADM-3A question
>
> After hanging vertically for 36 hrs in a hot upstairs room, more goop
seeped
> out from under the keyboard. It now works again. Whew.
>
> While running on the bench for burn-in testing, a cursor problem suddenly
> appeared... it would only move every other keystroke. With the technical
> description and schematic at hand, it wasn't hard to track down a 74LS193
> up/down counter with a blown (floating) LSB output. Confirmed by manually
> toggling that bit and the cursor would move back and forth one position.
> Meanwhile I removed the bad chip and put in a DIP socket. Naturally my TTL
> collection didn't have an 'LS193 so I'm waiting on that. So I have a 24
line, 1
> column terminal :)
>
> The monitor was occasionally intermittent (no display at all, no HV, +15
and
> drive signals OK). It seemed to change with movement of the wiring harness
> from the main board to the monitor, too. I reseated the edge connector on
its
> PCB and it seemed to be fixed - but then the VERTICAL deflection collapsed
and
> tweaking the height adjustment caused increasing loss. The 100 ohm pot to
the
> base of the vertical output transistor had picked that moment to go open.
> Changed that out and readjusted everything - so far so good after another
hour
> of run time.
>
> This ADM-3A could have been unpowered (and in a storage area without
> climate
> control) for a very long time. I wonder if that contributed to the
failures I'm
> seeing... hope there aren't any more until I get to use it for a while on
my PDP-
> 8/A (or 11/23+).
>
>
> ---
> This email has been checked for viruses by Avast antivirus software.
> https://www.avast.com/antivirus
Will...
I?m still waiting for you and the Rhode Island Computer Society to get my brand new in the box 9766, the Alignment disk platter, the box of spare heads and the other unit 9766 beat up unit up and running that I gave you to donate to RICS for free in exchange for you reading the dozen 300mb platters I have and then once the data was read they could keep the platters...
So still waiting on that... hint hint hint
> ------------------------------
>
> Message: 3
> Date: Mon, 12 Aug 2019 14:09:16 -0400
> From: William Donzelli <wdonzelli at gmail.com>
> To: P Gebhardt <p.gebhardt at ymail.com>, "General Discussion: On-Topic
> and Off-Topic Posts" <cctalk at classiccmp.org>
> Subject: Re: Control Data 9766 drive on epay
> Message-ID:
> <CANij+dfgBwBbQ2E29umm_QUx6duuwQANQ35cGgsmC7MbOkiXVw at mail.gmail.com>
> Content-Type: text/plain; charset="UTF-8"
>
> There is a Make Offer option, and it does look like the seller does
> take offers fairly regularly. I will not be buying it.
>
> If someone does, I have a huge amount of spares for 976x drives,
> including refurbished heads. It might take a while to find them in my
> mess, however.
>
> --
> Will
>
>
Good evening, folks...
Does anybody know if Datapoint made monitors for Convergent
Technologies? In my "near junk" section I have some modules that someone
stored in a warehouse next to a carpenter shop and under bombardment
>from bats and birds.? The modules were made by Convergent Technologies
and I never did much about them because of their extremely dirty state
and also because of the lack of a keyboard.? I have:
- Two CP-001/8 cpu modules (80186 at 8MHz, 256KB RAM, 6845 video IC)
- Four 5 1/4" dual-floppy modules (each has two Mitsubishi M4853
half-height drives)
- One GC-001 graphics controller
- Two PS-001 power supplies, one is missing parts
and then, a monitor that by the looks and controls is a VC-002 15" to be
used with the GC-001, except that it is labeled as:
Datapoint Corp.
Model 97-1224-001
Serial 934055
Other marks:? 53-00355-00???? 5-84
So, do you guys know if Datapoint made monitors for others?
Carlos.
> From: Paul Koning
> Isn't the interrupt disabled by RESET?
Nope. On the -11/03 and KDF11-A, BEVNT is wired straight into the CPU, and
there's no internal register to control it.
The BDV11 does have a register which can enable/disable the LTC (it connects
BEVNT to ground via a transistor when the appropriate register bit is
cleared); but, ironically (given your question), BINIT/RESET does _not_ clear
that register! Only BPOK does. (My theory is they were short of a bus receiver
for BINIT, and rather than put a whole extra chip on the card...) So, once on,
it has to be explicitly turned off, or the 'boot' switch (which toggles BPOK)
has to be hit.
The KDF11-B and all KDJ11 machines do have the LTC register, which operates
'correctly'.
Noel
> From: Jerry Weiss
> I turned BEVENT off and it boots successfully. I am not immediately
> sure why this is necessary.
If an LTC interrupt happens before the OS has set up the LTC vector, etc,
hilarity ensues.
E.g. the LTC has to be turned off before UNIX V6 will boot on an -11/23:
http://gunkies.org/wiki/Running_UNIX_V6_on_an_-11/23
I discovered this the hard way; I roached the disk on my simulated /23
when I didn't.
Noel
After hanging vertically for 36 hrs in a hot upstairs room, more goop seeped
out from under the keyboard. It now works again. Whew.
While running on the bench for burn-in testing, a cursor problem suddenly
appeared... it would only move every other keystroke. With the technical
description and schematic at hand, it wasn't hard to track down a 74LS193
up/down counter with a blown (floating) LSB output. Confirmed by manually
toggling that bit and the cursor would move back and forth one position.
Meanwhile I removed the bad chip and put in a DIP socket. Naturally my TTL
collection didn't have an 'LS193 so I'm waiting on that. So I have a 24
line, 1 column terminal :)
The monitor was occasionally intermittent (no display at all, no HV, +15 and
drive signals OK). It seemed to change with movement of the wiring harness
>from the main board to the monitor, too. I reseated the edge connector on
its PCB and it seemed to be fixed - but then the VERTICAL deflection
collapsed and tweaking the height adjustment caused increasing loss. The 100
ohm pot to the base of the vertical output transistor had picked that moment
to go open. Changed that out and readjusted everything - so far so good
after another hour of run time.
This ADM-3A could have been unpowered (and in a storage area without climate
control) for a very long time. I wonder if that contributed to the failures
I'm seeing... hope there aren't any more until I get to use it for a while
on my PDP-8/A (or 11/23+).
---
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