Re: ISO: RL02 cable

[william degnan]

On Sat, Dec 17, 2016 at 12:32 AM, Josh Dersch  wrote:

> Hi all --
>
> I'm in need of an RL02 cable (drive to drive).  I picked up a second drive
> for my PDP-11/40 and I'd like to get it hooked up.
>
> Thanks as always,
>
> Josh
>
>
I don't have a spare, but just to follow up on our earlier conversation I
was able to remedy the DC LO issue on my 11/40 so I could work on 15V going
to the RL11 controller as you suggested.  One issue remains however.

When I power on I get the correct quiescent lights, but address line 16
comes on when one pressed the LOAD ADDR switch for any address, (and paddle
16 was not up)?   Same effect if I switch out RAM, it's not caused by the
RAM nor  the M9312.  I still get this effect even if I have no RAM in the
system.  I thought for sure this was a specific error, but I can't seem to
find it in my notes or docs.  I have seen this before.  M7231?  If you know
great if not I will keep looking and testing.  I am very encouraged as to
your progress with the 11/34 and I hope soon to finally get my 11/40
booting with an RL02.

BIll

Re: heavy stuff -- was: Anyone want an RK11-C manual?

[Tony Duell]

On Sat, Dec 17, 2016 at 1:28 AM, Paul Koning  wrote:
>
>> On Dec 16, 2016, at 4:43 PM, Noel Chiappa  wrote:
>>
>>> From: Henk Gooijen
>>
>>> I really do not want to mess with the mechanical construction of the
>>> entire RP03 drive. ... I want to move them "as is".
>>
>> Well, don't forget, you're probably going to want to go through them
>> thoroughly before you try and use them, and you might do a fair amount of
>> dis-assembly for that anyway. So a certain amount of 'taking apart' to get
>> it out would be useful.
>
> Disconnecting controllers from the drive electronics, or main drive logic 
> boards
> from the head cabling, might be a reasonable thing to do.
>
> Disassembling the mechanics is quite another matter.  The spindle and head
> actuator assemblies are precision mechanisms with very tight tolerances and
>  alignment requirements.  It's not clear if those are documented since messing
>  with them in the field would not be normal practice.  And I suspect that 
> few, if
>  any, of us have the tools or metrological skills to reassemble dismantled 
> drives.

As I said, I would not touch any part of the heads or positioner
(actuator). Unless
whole assembly can be removed as a complete 'module' (as is the case in the
RA60). I also would not attempt to dismantle the spindle.

But often the complete spindle and bearings can be unbolted and lifted out. On
a servo-positioned drive (as I believe this is) this will not affect
alignment. And
replacing the complete spindle assembly was a field repair on most such drives.

Things like the spindle motor (I assume this drive is belt driven),
blower, etc are
not that critical and can be removed without problems.

Is the a maintenance manual for this drive available. It should give
the order for
removing parts (basically don't do anything that involves removing heads!) and
tell you if any alignment is needed when replacing them.


-tony

ISO: RL02 cable

[Josh Dersch]

Hi all --

I'm in need of an RL02 cable (drive to drive).  I picked up a second 
drive for my PDP-11/40 and I'd like to get it hooked up.


Thanks as always,

Josh

Re: heavy stuff -- was: Anyone want an RK11-C manual?

[Paul Koning]

> On Dec 16, 2016, at 4:43 PM, Noel Chiappa  wrote:
> 
>> From: Henk Gooijen
> 
>> I really do not want to mess with the mechanical construction of the
>> entire RP03 drive. ... I want to move them "as is". 
> 
> Well, don't forget, you're probably going to want to go through them
> thoroughly before you try and use them, and you might do a fair amount of
> dis-assembly for that anyway. So a certain amount of 'taking apart' to get
> it out would be useful.

Disconnecting controllers from the drive electronics, or main drive logic 
boards from the head cabling, might be a reasonable thing to do.

Disassembling the mechanics is quite another matter.  The spindle and head 
actuator assemblies are precision mechanisms with very tight tolerances and 
alignment requirements.  It's not clear if those are documented since messing 
with them in the field would not be normal practice.  And I suspect that few, 
if any, of us have the tools or metrological skills to reassemble dismantled 
drives.

Some are less fussy.  I know from having seen it done that you can take an RF11 
drive apart and rebuild it, though chances are you might have to reformat it if 
you do.  But the tolerances on those are incredibly loose compared to moving 
head drives.

paul

RE: Rack-mounting a TU56

[Jay West]

I had written
> Being a stickler for authenticity, I was looking for that support bracket but 
> never did find one.
> So... I wound up using one of those horizontal bars/plates that were 
> commonly (DEC provided) mounted above and below a stack of lead 
> counterweights, as it's mechanically almost identical and provides 
> exactly the same benefit in the same spot. I left it installed, in case I 
> ever wanted to move the TU56.

To which Tony replied
-
I am not sure what parts you are talking about here, or why.
-

I am talking about a fairly common dec part, that if you have it - can 
substitute for the support bracket that you are missing. It is the same 
dimensions, is threaded at the same spots... the only difference was the 
support bracket has some metal cutouts that the "alternate" part doesn't.

If you have a DEC rack (I know DEC did this in H967's and may have done it in 
H960's) that has lead counterweights in the back you will note that the 
plates bolted in the rack under the lead weights (and usually another plate on 
top of them just to make it look nice)  that plate is basically identical 
to the TU-56 support bracket you are seeking and will work functionally - 
exactly like the support bracket.

J

A Healthy Haul for the Holidays? Tuscon, AZ

[Jason T]

Spotted on Craigslist, no prices known, no relation to seller, but
some nice items:

https://tucson.craigslist.org/sys/5846658097.html


Highlights (IMO):  3B2/400, Xerox Star, HP6000/300, Televideo 910 and
lots of micro and workstation stuff besides.

-j

Re: heavy stuff -- was: Anyone want an RK11-C manual?

[Noel Chiappa]

> From: Henk Gooijen

> I really do not want to mess with the mechanical construction of the
> entire RP03 drive. ... I want to move them "as is". 

Well, don't forget, you're probably going to want to go through them
thoroughly before you try and use them, and you might do a fair amount of
dis-assembly for that anyway. So a certain amount of 'taking apart' to get
it out would be useful.

Noel

Re: Found in data center

[Guy Sotomayor Jr]

Contact me off-list (g...@shiresoft.com) for shipping information.

Thanks.

TTFN - Guy

> On Dec 16, 2016, at 9:35 AM, Pete Lancashire  wrote:
> 
> Hello,
> 
> If I can get the stuff (They would not let me have the mainframe) I'll let
> you know. No problem shipping since I doubt anything is fragile.
> 
> -pete
> 
> On Thu, Dec 15, 2016 at 10:20 AM, Guy Sotomayor Jr 
> wrote:
> 
>> If no one else wants/claims this, I will as it looks like mainframe stuff.
>> 
>> Will you box/ship?
>> 
>> TTFN - Guy
>> 
>>> On Dec 14, 2016, at 10:54 AM, Pete Lancashire 
>> wrote:
>>> 
>>> An old cabinet that only IBM had the key, they came by took what they
>>> wanted and left it full
>>> 
>>> I only got a quick shot of what's in there .. any interest ? Located
>>> Portland, Oregon
>>> 
>>> https://goo.gl/photos/rSUZ9nnxsrxN8nku5
>> 
>> 
>> 

RE: Rack-mounting a TU56

[Henk Gooijen]

Van: Jay West
Verzonden: vrijdag 16 december 2016 21:05
Aan: 'General Discussion: On-Topic and Off-Topic 
Posts'
Onderwerp: RE: Rack-mounting a TU56

Ok I just double-checked my 8E racks, and it refreshed my memory.

The support bracket is not necessary. I believe that it provided no benefit 
after the TU56 was mounted... it was merely present in order to make it even 
possible for one person to bolt the tu56 to the uprights. It is a non-trivial 
amount of weight, so holding it in place while bolting it in is tenuous at the 
least and most likely impossible. The support bracket just provides a front 
edge to help hold it up during installation.

But given the weight, I'd not try it "just to see" ;) YMMV



That is my experience too.
But I did that mounting job in the rack back when I was 15 years
younger. Age does not help in this case.
It can be done by one person, but indeed – it is not non-trivial!

If you start with an empty rack, and the TU56 is the first device you
want to install in the rack, you can lay down the rack on the floor
and then “drop” the drive into the rack. Bolting it in place with the
4 screws at each side is “piece of cake”.
I used this “procedure” also to mount two RK05 drive in the top of an
H960 rack. Getting the rack upright with the two RK05’s was another
story … The more a rack is filled (in the lower part), the heavier tilting
and laying down will become, but it is possible.


  *   Henk, PA8PDP

Re: Rack-mounting a TU56

[Ethan Dicks]

On Fri, Dec 16, 2016 at 3:05 PM, Jay West  wrote:
> Ok I just double-checked my 8E racks, and it refreshed my memory.
>
> The support bracket is not necessary...
>
> All this occurred in the short version of the H960 (I forget... H962? The one 
> with the sloped front).

H967

http://web.aanet.com.au/~malikoff/pdp11/DEC_cabinets.jpg

> The sloped front at the top was just the tiniest fraction too far out to 
> allow the TU56 deck to tilt down - despite the fact that DEC obviously took 
> pains to make it require no clearance overhead.

That is exactly what I was just wondering.  Thanks!

-ethan

Re: heavy stuff -- was: Anyone want an RK11-C manual?

[Tony Duell]

On Fri, Dec 16, 2016 at 8:23 PM, Henk Gooijen  wrote:
>


> Grin … I don’t plan to check whether Mother Earth’s acceleration is still 
> working fine.
> Indeed, the RA60 is heavy. Just like RA81’s, the RA60 is not good for your 
> back, but
> the RA60 is worse than the RA81. The RA60 is also “longer” compared to the 
> RA81,
> and that does not help either when you hav to move an RA60 around.


I'm doing an RA80-like thing soon. Actually an R80, going at the
bottom of a half-height
rack for the 11/730. I am building that one up in the rack. No way am
I lifting it
fully assembled (and actually DEC suggest you remove the HDA first).

>
> I really do not want to mess with the mechanical construction of the entire 
> RP03
> drive. They are too rare. I want to move them “as is”. The only thing that 
> can be
> done easily is removing the side panels.

Maybe I have more (unjustified) confidnnce in my abilities to get
things back together
again, but in my case I think I would feel there was less risk of
damage if I took the
thing apart than if I tried to move it assembled. I wouldn't touch the
heads or positioner
parts (A full alignment would be 'interesting') but I would certainly
remove the spindle
all PCBs, mains transformer/PSU parts, blower, etc.

> However, the ceiling in the cellar has an opening although that is currently 
> welded
> by a closing lid. The system was installed in the 80ties, and it is not 
> remembered
> how the system got into the cellar back then. The system has operated in that 
> cellar
> for almost 20 years (PDP-11/40, RP11, Kennedy 9100 – 3 H960 rack system).
>
> I used wooden planks (shelves) laid on the stairs, and then pushed the racks 
> up.
> It was heavy, even for 3 strong guys --- OK, 2.5    I removed the Kennedy 
> tape

Get more strong friends :-). Be warned that unless they have experience in
moving classic computers you might regret it,

-tony

Re: Found in data center

[Pete Lancashire]

Hello,

If I can get the stuff (They would not let me have the mainframe) I'll let
you know. No problem shipping since I doubt anything is fragile.

-pete

On Thu, Dec 15, 2016 at 10:20 AM, Guy Sotomayor Jr 
wrote:

> If no one else wants/claims this, I will as it looks like mainframe stuff.
>
> Will you box/ship?
>
> TTFN - Guy
>
> > On Dec 14, 2016, at 10:54 AM, Pete Lancashire 
> wrote:
> >
> > An old cabinet that only IBM had the key, they came by took what they
> > wanted and left it full
> >
> > I only got a quick shot of what's in there .. any interest ? Located
> > Portland, Oregon
> >
> > https://goo.gl/photos/rSUZ9nnxsrxN8nku5
>
>
>

Re: Mystery 8085-related IC identification needed please

[allison]

On 12/16/2016 08:43 AM, Adrian Graham wrote:
> Hi folks,
>
> I have an 8085-based viewdata telephone system on the bench that's proving
> to be a labour of love in trying to get it running with zero documentation -
> there are only 6 known examples that I've come across and all but 2 of them
> are in museums, none known to work. If any of you fancy searching it's an
> STC Executel 3910 and at least two of the hits you'll get will be my machine
> before I bought it.
>
> http://www.binarydinosaurs.co.uk/stcexecutel01.jpg
>
> I've been in contact with all museums who have one, no luck on docs though
> the Museum of Computing which is local to me MAY have some (Jason the owner
> has 2 3910s himself), I just need to get down there and search for it :)
>
> Kind-of-fortunately the viewdata side of things seems standard - all 74LS
> TTL with an MC3242AP running 16x 4116-2 DRAMs, 27128 EEPROMs etc. The
> viewdata side of things is powered by a Plessey MR9735-002 teletext
> processor supported by a pair of 2112 RAM chips and an SAA5070 "LUCY".
>
> http://txlib.mb21.co.uk/main.php?g2_view=core.DownloadItem_itemId=2034
>
> ROM selection is done by a PAL but my EEPROM reader has verified that's OK
> and I have a dump of it as well as all the ROMs.
>
> Unfortunately it's suffered battery leakage and it was seemingly stored on
> its back in a very damp environment so some of the capacitors at the rear of
> the board have rotted and bits of the analogue board for the 5" TV had
> rusted to nothing, though I've replaced those.
>
> What I originally thought was an analogue board issue that I posted about
> here has turned into a total lack of timing issue so I've been tracing out
> all the circuits and building a schematic of the board. All was well until I
> came to the two chips you can see in the centre of this pic that have no
> markings (9B and 10B on the board):
>
> http://www.binarydinosaurs.co.uk/stcexecuteltimingcircuits.jpg
>
> They aren't 'standard' 14-pin DIPs in that they don't follow the
> GND-on-pin-7-Vcc-on-pin-14 layout. Pins 6 and 7 on both are wired together
> (not to GND) and form the RESET signal for the 8085 via the 7414 at 10A,
> source for this signal is unknown currently. Pin 5 on both appears to be Vcc
> and pin 10 is GND or at least are pulled high and low respectively.
>
> The XTAL you can see with its supporting resistors is connected to the 7404
> at 12B, pin 12 of which goes to pin 1 of 10B (one of the mystery chips) and
> pin 1 (X1) of the 8085.

IF I had to throw a wild guess either a baud rate generator chip, an
N-stage counter
like CD4040 or 4060 or one of many low number cmos (CD4xxx parts) wired
as oscillator.
most of those had non TTL style pin outs.

Allison

> Any clues? I'm going to search for reference 8085 boards (and I guess 8086?)
> layouts to see if there are any similarities in timing circuits but for now
> I'm stumped.
>
> Cheers!
>

Re: Rack-mounting a TU56

[Marc Howard]

I replaced my motor caps with some that I found on Alibaba (or maybe
Aliexpress) a couple of years ago.  They are the right diameter and height
and have wire leads instead of lugs. They're also made with yummy vegatable
oil and seem to work just fine (no big loud bangs yet).

Marc

On Fri, Dec 16, 2016 at 11:15 AM, jos  wrote:

>
> Speaking of which - I'll put out a call again for if anyone wants to get a
>> group purchase on the motor run caps for a TU55/56
>>
>
> Count me in
>
> Jos
>

HP 9875A usable for interchange with 85 or 9825?

[Craig Ruff]

I’m working on getting my 9875A dual DC100A tape drive operational, but have 
come across a strange issue.  This 9875A seems to have the reversed sense of on 
which reel the rewind places the tape as compared to my 85B and 9825T (which 
agree is the left hand one as viewed when inserting the tape into the drive).  
I don’t yet know that the 9875A is operating fully, but it passes the non-tape 
movement selftest.

The 9875A manual mentions it being useful for interchange among systems, and 
the tape structure (Standard Interchange Format - SIL) matches that of the 98x5 
series, and it appears uses the same tape control chip as described in the 
April 1978 HP Journal article on the 9845.  I guess there could be a failure on 
the tape control board that is reversing the motor control direction, as both 
drives behave in the same way, or is causing the firmware to think it is at the 
wrong end of the tape.

Has anyone used the 9875A in this way?  I was thinking it could be a way to 
load binary programs into the 9825.

Re: Rack-mounting a TU56

[Pontus Pihlgren]

On Fri, Dec 16, 2016 at 01:12:45PM -0600, Jay West wrote:
> 
> Speaking of which - I'll put out a call again for if anyone wants to get 
> a group purchase on the motor run caps for a TU55/56
> 

Are these the big honking cans that have grown a nice little crystal 
structure near one connector?

yeah, I thunk I need a pair for mu TU56H

If me being in sweden makes it to much hassle then I'm I'll try to get them 
myself, no worries.

/P

Re: Rack-mounting a TU56

[Tony Duell]

On Fri, Dec 16, 2016 at 8:05 PM, Jay West  wrote:
> Ok I just double-checked my 8E racks, and it refreshed my memory.
>
> The support bracket is not necessary. I believe that it provided no benefit 
> after the TU56
> was mounted... it was merely present in order to make it even possible for 
> one person
> to bolt the tu56 to the uprights. It is a non-trivial amount of weight, so 
> holding it in place
> while bolting it in is tenuous at the least and most likely impossible. The 
> support bracket
> just provides a front edge to help hold it up during installation.

OK. Sounds like I can live without it. I had considered making a rail
with tapped holes
in the ends to mount across the rack on the front set of side flanges.
But I don't
think I need that.

>

> Being a stickler for authenticity, I was looking for that support bracket but 
> never did find one.
> So... I wound up using one of those horizontal bars/plates that were commonly 
> (DEC provided)
> mounted above and below a stack of lead counterweights, as it's mechanically 
> almost identical
> and provides exactly the same benefit in the same spot. I left it installed, 
> in case I ever wanted
> to move the TU56.

I am not sure what parts you are talking about here, or why.

>
> All this occurred in the short version of the H960 (I forget... H962? The one 
> with the sloped front).
> The sloped front at the top was just the tiniest fraction too far out to 
> allow the TU56 deck to tilt
> down - despite the fact that DEC obviously took pains to make it require no 
> clearance overhead.
> Since you're using a full height H960 with a different nameplate piece at the 
> top... it may just
>  work fine.
>
> But given the weight, I'd not try it "just to see" ;) YMMV

The recommendation in the manual is to remove the front panel from the
TU56, rack mount
the chassis and put the panel back on.

I think I do have to try it to see and I am doing it on my own. But
then again, I have rack-mounted
other heavy units on my own...

-tony

Re: Rack-mounting a TU56

[Vincent Slyngstad]

From: Jay West: Friday, December 16, 2016 11:12 AM
Speaking of which - I'll put out a call again for if anyone wants to get a 
group purchase on the motor run caps for a TU55/56


I have a couple of spares, IIRC, but since I also have a couple of TU55,
a couple of TU56, and a TU56H, I'd like to join in if there is a group
purchase.

   Vince 

RE: Rack-mounting a TU56

[Jay West]

Ok I just double-checked my 8E racks, and it refreshed my memory.

The support bracket is not necessary. I believe that it provided no benefit 
after the TU56 was mounted... it was merely present in order to make it even 
possible for one person to bolt the tu56 to the uprights. It is a non-trivial 
amount of weight, so holding it in place while bolting it in is tenuous at the 
least and most likely impossible. The support bracket just provides a front 
edge to help hold it up during installation.

Being a stickler for authenticity, I was looking for that support bracket but 
never did find one. So... I wound up using one of those horizontal bars/plates 
that were commonly (DEC provided) mounted above and below a stack of lead 
counterweights, as it's mechanically almost identical and provides exactly the 
same benefit in the same spot. I left it installed, in case I ever wanted to 
move the TU56.

All this occurred in the short version of the H960 (I forget... H962? The one 
with the sloped front). The sloped front at the top was just the tiniest 
fraction too far out to allow the TU56 deck to tilt down - despite the fact 
that DEC obviously took pains to make it require no clearance overhead. Since 
you're using a full height H960 with a different nameplate piece at the top... 
it may just work fine.

But given the weight, I'd not try it "just to see" ;) YMMV

J

RE: Rack-mounting a TU56

[Henk Gooijen]

Van: Ethan Dicks
Verzonden: vrijdag 16 december 2016 20:43
Aan: General Discussion: On-Topic and Off-Topic 
Posts
Onderwerp: Re: Rack-mounting a TU56

On Fri, Dec 16, 2016 at 2:12 PM, Jay West  wrote:
> Speaking of which - I'll put out a call again for if anyone wants to get a 
> group purchase on the motor run caps for a TU55/56

I need a few.

-ethan



I have one TU56. There will come a day that I am up to connect it …
Until then I don’t know in what shape the run caps are, so I probably
do wise to join in this group buy opportunity – depending the cost 


  *   Henk, PA8PDP

Re: Rack-mounting a TU56

[Ethan Dicks]

On Fri, Dec 16, 2016 at 2:18 PM, Tony Duell  wrote:
> On Fri, Dec 16, 2016 at 7:12 PM, Jay West  wrote:
>> Tony wrote...
>>> Anyway, does anyone have experience of rack-mounting a TU56?
>>
>> I can tell you - be careful about putting it all the way at the top. The 
>> front deck can't tilt
>> downward if the upper edge doesn't have clearance.
>
> ARGH. I was planning on putting it at the top of the rack. But surely it will
> just catch on that plastic decor panel, I can either trim that a bit
> or put spacers under the fixing screws.

I checked my one H960 - the TC11 is at the top, then both TU56s are
below that, where someone my height can reach the tapes.  ;-)

The TU56 on a TD8E on my PDP-8/e has always been on the table.  It's
never been in a rack.  If I find another H967 cabinet, that will be a
good thing to check since the TU56 would be easy to use in the top
spot (there's no top-mount plastic panel on an H967, so it might fit
there just fine).

-ethan

Re: Rack-mounting a TU56

[Ethan Dicks]

On Fri, Dec 16, 2016 at 2:12 PM, Jay West  wrote:
> Speaking of which - I'll put out a call again for if anyone wants to get a 
> group purchase on the motor run caps for a TU55/56

I need a few.

-ethan

Re: Rack-mounting a TU56

[Tony Duell]

On Fri, Dec 16, 2016 at 7:12 PM, Jay West  wrote:
> Tony wrote...
>> Anyway, does anyone have experience of rack-mounting a TU56? It
>> clearly doesn't go on slide rails, it bolts directly to the rack
>> (hinge down the front panel for access). I have the manuals from
>> Bitsavers, they imply there is some kind of spacer block that goes
>> under the TU56. Does anyone know what that is exactly so  I can
>> attempt to make one if it is needed.
>
> Yes, I rackmounted a tu56 a few weeks ago. I also saw the docs mention that
> spacer, but I think it wasn't technically necessary based on where I was 
> putting
> it. I will go look at that rack shortly and let you know today.

OK, thanks, Are the screws through the TU56 front flanges into the
front rails of the rack
enough to support it?

I don't care too much what it looks like. If the spacer is just a
filler panel type thing
and doesn't support the TU56 in any way then I don't need to worry about
it.

>
> I can tell you - be careful about putting it all the way at the top. The 
> front deck can't tilt
> downward if the upper edge doesn't have clearance.

ARGH. I was planning on putting it at the top of the rack. But surely it will
just catch on that plastic decor panel, I can either trim that a bit
or put spacers under
the fixing screws.

The only other think I could put at the top is the PC04, perhaps that would
be easier.
>
> Then again - anyone who has met me knows I'd never mount a peripheral 
> requiring
> hands on that far up in a cabinet *grin*

I am tall enough that that is not a problem.

-tony

Re: Rack-mounting a TU56

[jos]

Speaking of which - I'll put out a call again for if anyone wants to get a 
group purchase on the motor run caps for a TU55/56


Count me in

Jos

Re: Mystery 8085-related IC identification needed please

[Tony Duell]

On Fri, Dec 16, 2016 at 6:19 PM, Peter Coghlan  wrote:
>>
>> They aren't 'standard' 14-pin DIPs in that they don't follow the
>> GND-on-pin-7-Vcc-on-pin-14 layout. Pins 6 and 7 on both are wired together
>> (not to GND) and form the RESET signal for the 8085 via the 7414 at 10A,
>> source for this signal is unknown currently. Pin 5 on both appears to be Vcc
>> and pin 10 is GND or at least are pulled high and low respectively.
>>
>
> Could they be 74(LS)90? Those have Vcc on pin 5 and GND on pin 10.

And IIRC pins 6 and 7 are reset _inputs_ on the 74x90 (I don't have the
pinouts to hand, what about the 74x92 or more likely 74x93?). But active
high, not active low. So it's possible the reset signal comes from elsewhere,
resets these counters (as some kind of clock divider chain) and is inverted
by that '14 to feed the 8085 reset input.

I doubt it's a uA733. I can think of no logical reason to have one of those
in this sort of circuit.

-tony

Re: Mystery 8085-related IC identification needed please

[Peter Coghlan]

>
> They aren't 'standard' 14-pin DIPs in that they don't follow the
> GND-on-pin-7-Vcc-on-pin-14 layout. Pins 6 and 7 on both are wired together
> (not to GND) and form the RESET signal for the 8085 via the 7414 at 10A,
> source for this signal is unknown currently. Pin 5 on both appears to be Vcc
> and pin 10 is GND or at least are pulled high and low respectively.
>

Could they be 74(LS)90? Those have Vcc on pin 5 and GND on pin 10.

Regards,
Peter Coghlan.

Re: Mystery 8085-related IC identification needed please

[Vincent Slyngstad]

From: Adrian Graham: Friday, December 16, 2016 5:43 AM

They aren't 'standard' 14-pin DIPs in that they don't follow the
GND-on-pin-7-Vcc-on-pin-14 layout. Pins 6 and 7 on both are wired together
(not to GND) and form the RESET signal for the 8085 via the 7414 at 10A,
source for this signal is unknown currently. Pin 5 on both appears to be Vcc
and pin 10 is GND or at least are pulled high and low respectively.


If you had Vcc on 10 and GND on 5, I'd suggest UA733.  There aren't a 
lot of 14 pin chips with the power pins on 5 and 10.  (More with 4 and 11.)


   Vince 

Re: Anyone want an RK11-C manual?

[Tony Duell]

On Fri, Dec 16, 2016 at 4:31 PM, Henk Gooijen  wrote:
>
>
> Van: Noel Chiappa
> Verzonden: vrijdag 16 december 2016 17:08
> Aan: cctalk@classiccmp.org
> CC: j...@mercury.lcs.mit.edu
> Onderwerp: Anyone want an RK11-C manual?
>
> As I finish going through the mounds of paper I've recently aquired, I now
> have a extra (duplicate) copy of the RK11-C manual (in the format of the early
> 11/20 manuals, i.e. 11"x17" sheets).
>
> Is anyone here qinterested in having it? Preferably somehow who actually has
> an RK11-C - I know there's at least one person on CCTalk who has one.
>
> If so, please let me know. (People who actually have an RK11-C get
> preference. And if you already have a copy, please don't try and hoard a
> second! :-)
>
> Noel
>

To comment on that, I have an RK11-C, but I am pretty sure I have the
manual. I certainly have an original of the printset.

>

>
> But I am not giving up hope … I recently acquired something I did not think
> to be possible to happen … I “picked up” an H960 rack with RP11 controller
> and *three* RP03 disk drives aand 6 packs.  The rack is already moved, the
> drives are a separate story. Each drive weighs 415 lbs. “So what” you might
> ask. Well, they are in a cellar and three flights of stairs (10 steps, 6 
> steps,
> and 4 steps) is too much for 3 strong guys to push one drive up the stairs.
> We are now looking into another option to get the drives (and a DEC
> _line_printer, also very very heavy!) up to the first floor …

Can these units be dismantled without totally losing alignment,etc. At least
remove PSUs, spindle motors, etc. I once moved an RA60 (much lighter,
but still too heavy for one person to carry easily) downstairs by taking it
almost completely apart. Incidentally, it is surprising how much the PCBs
in a full cardcage weight, it is often worth pulling them all out.

I suspect an RP03 dismantled like that would still be too heavy for one person
to move, but with 3 people it might be possible.

I hope your upstairs floor is strong enough for them... You do not want them
coming back downstairs at 9.81m/s^2

-tony

Re: Anyone want an RK11-C manual?

[Fritz Mueller]

> Is anyone here qinterested in having it? Preferably somehow who actually has
> an RK11-C - I know there's at least one person on CCTalk who has one.

Hi Noel — I have an RK11-C (and two RK05s) that I am just about to dive in on.  
I would appreciate this document, unless it is needed for scanning by any of 
the archivists?

thanks,
   —FritzM.

Re: PDP-6s at MIT

[Noel Chiappa]

> From: Lars Brinkhoff

> I wonder how the AI PDP-6 was used back in the day.  I suppose ITS
> development moved to the KA10 using the virtual memory pager, leaving
> the 6 behind.  But it was still attached as a slave CPU, right?

Yes. There is a document, "February 1972 ITS Status Report", AIM-238, which is
from a point in time when both CPUs were in operation as a dual-CPU system,
with paging on the KA10, and it contains a considerable amount of technical
detail. It is available here:

  https://dspace.mit.edu/handle/1721.1/6194

as a scan, and someone has recently OCR'd it, here:

  http://its.victor.se/wiki/aim-238

The section you probably find most interesting is "Dual Processors" (pg. 29),
which describes the unified, shared I/O bus.

The earlier "ITS 1.5 Status Manual" might also be interesting; it covers a
point in time when I think they only had a PDP-6.


>> I think all the DM people are still around - why not ask one of them
>> for more?

> I will.

I'd be interested to hear anything about the DM PDP-6 which you find out.

Ideally it would be optimal to load any information into the Computer History
Wiki, but alas, creation of new accounts on that seems to be wedged at the
moment; I'm working on trying to get that solved.

Noel

RE: Anyone want an RK11-C manual?

[Henk Gooijen]

Van: Noel Chiappa
Verzonden: vrijdag 16 december 2016 17:08
Aan: cctalk@classiccmp.org
CC: j...@mercury.lcs.mit.edu
Onderwerp: Anyone want an RK11-C manual?

As I finish going through the mounds of paper I've recently aquired, I now
have a extra (duplicate) copy of the RK11-C manual (in the format of the early
11/20 manuals, i.e. 11"x17" sheets).

Is anyone here qinterested in having it? Preferably somehow who actually has
an RK11-C - I know there's at least one person on CCTalk who has one.

If so, please let me know. (People who actually have an RK11-C get
preference. And if you already have a copy, please don't try and hoard a
second! :-)

Noel


I remember a week in 2005 (or thereabouts) when one RK11-C was on eBay.
It went for $57 (IIRC).  There have been a few occasions since then that I
slap myself for not at least trying to get it ☹
Never seen a single RK11-C ever since.

But I am not giving up hope … I recently acquired something I did not think
to be possible to happen … I “picked up” an H960 rack with RP11 controller
and *three* RP03 disk drives aand 6 packs.  The rack is already moved, the
drives are a separate story. Each drive weighs 415 lbs. “So what” you might
ask. Well, they are in a cellar and three flights of stairs (10 steps, 6 steps,
and 4 steps) is too much for 3 strong guys to push one drive up the stairs.
We are now looking into another option to get the drives (and a DEC
_line_printer, also very very heavy!) up to the first floor …


  *   Henk, PA8PDP

Anyone want an RK11-C manual?

[Noel Chiappa]

As I finish going through the mounds of paper I've recently aquired, I now
have a extra (duplicate) copy of the RK11-C manual (in the format of the early
11/20 manuals, i.e. 11"x17" sheets).

Is anyone here qinterested in having it? Preferably somehow who actually has
an RK11-C - I know there's at least one person on CCTalk who has one.

If so, please let me know. (People who actually have an RK11-C get
preference. And if you already have a copy, please don't try and hoard a
second! :-)

Noel

Re: An interesting use of the 4004 instructions

[dwight]

The 4004 destroys the ACC on return from subroutine calls and one

would have to use hard coded values to pass a value back so it

is common to the use carry flag in a similar way to pass a status

back.

Since this the address part of the JCN instruction doesn't matter if

it never does the branch, that is used as an entry point for the

execution.

The code would look like:

LDM 0

SKIP

LDM 1

SKIP

LDM 2

SKIP

LDM 3

XCH 4

SCR 4

BBL 0


Each of the LDM instructions is a point to branch into. Only the instruction

at the first address is executed and the others are skipped.

BBL is the I4004 return instruction, it loads the value into the ACC.

I've looked at a several cases of I4004 code and this is the first time that

I'd seen this skip trick used.

The SKIP is really the JCN instruction without any condition and the address

replaced by the LDM instruction. At first I thought it was bit rot in the old

ROMs but each entry is used 8 times in code.

It would be a JCN NEVER? One wonders what the assembly code originally

looked like.

Dwight



From: cctalk  on behalf of Paul Koning 

Sent: Thursday, December 15, 2016 4:55:35 PM
To: General Discussion: On-Topic Posts
Subject: Re: An interesting use of the 4004 instructions


> On Dec 15, 2016, at 2:52 PM, dwight  wrote:
>
> I was looking at some disassembled 4004 code when I came across
>
> a SKIP operation.
>
> It isn't normally an instruction but If you do a JCN with all the  = 0,
>
> it will do a NEVER jump.
>
> This is the equivalent of a SKIP instruction.
>
> I would suppose a JCN with  = $8000 would be an always jump,
>
> on page ( not real useful as JUN takes the same cycles and space ).
>
> I thought at first there was some errors in the code because there
>
> were JMS to the middle of JCN instruction but then I noticed that there
>
> were no conditions specified for the JCN. A little thought and I realized
>
> it was a way to skip over a single byte instruction.

It's a bit like a coding convention I've seen used a lot in PDP-11 code, at 
least in some programs; RSTS/E is full of them.  Consider a function with two 
entry points, where Carry set or clear is used after entry to distinguish the 
two cases.  The two entry points look like this:

fun1:   tst (pc)+
fun2:   sec
; common code
bcs  case2
; case1...

Or a function that indicates a boolean result (say, success/fail) by Carry 
clear vs. set:

good:   tst (pc)+
fail:   sec
rts  pc

paul

Mystery 8085-related IC identification needed please

[Adrian Graham]

Hi folks,

I have an 8085-based viewdata telephone system on the bench that's proving
to be a labour of love in trying to get it running with zero documentation -
there are only 6 known examples that I've come across and all but 2 of them
are in museums, none known to work. If any of you fancy searching it's an
STC Executel 3910 and at least two of the hits you'll get will be my machine
before I bought it.

http://www.binarydinosaurs.co.uk/stcexecutel01.jpg

I've been in contact with all museums who have one, no luck on docs though
the Museum of Computing which is local to me MAY have some (Jason the owner
has 2 3910s himself), I just need to get down there and search for it :)

Kind-of-fortunately the viewdata side of things seems standard - all 74LS
TTL with an MC3242AP running 16x 4116-2 DRAMs, 27128 EEPROMs etc. The
viewdata side of things is powered by a Plessey MR9735-002 teletext
processor supported by a pair of 2112 RAM chips and an SAA5070 "LUCY".

http://txlib.mb21.co.uk/main.php?g2_view=core.DownloadItem_itemId=2034

ROM selection is done by a PAL but my EEPROM reader has verified that's OK
and I have a dump of it as well as all the ROMs.

Unfortunately it's suffered battery leakage and it was seemingly stored on
its back in a very damp environment so some of the capacitors at the rear of
the board have rotted and bits of the analogue board for the 5" TV had
rusted to nothing, though I've replaced those.

What I originally thought was an analogue board issue that I posted about
here has turned into a total lack of timing issue so I've been tracing out
all the circuits and building a schematic of the board. All was well until I
came to the two chips you can see in the centre of this pic that have no
markings (9B and 10B on the board):

http://www.binarydinosaurs.co.uk/stcexecuteltimingcircuits.jpg

They aren't 'standard' 14-pin DIPs in that they don't follow the
GND-on-pin-7-Vcc-on-pin-14 layout. Pins 6 and 7 on both are wired together
(not to GND) and form the RESET signal for the 8085 via the 7414 at 10A,
source for this signal is unknown currently. Pin 5 on both appears to be Vcc
and pin 10 is GND or at least are pulled high and low respectively.

The XTAL you can see with its supporting resistors is connected to the 7404
at 12B, pin 12 of which goes to pin 1 of 10B (one of the mystery chips) and
pin 1 (X1) of the 8085.

Any clues? I'm going to search for reference 8085 boards (and I guess 8086?)
layouts to see if there are any similarities in timing circuits but for now
I'm stumped.

Cheers!

-- 
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?

Re: DisplayWriter apparently on Craigslist...

[Al Kossow]

hopefully, someone can pick these up

it doesn't look like there is any software with it. would be nice to get
images if there is any software with it

if someone gets it, and tries to use the disk images on bitsavers, you
will need to bulk erase the floppy you copy the diagnostic disk to since
it expects one of the tracks to be unformatted


On 12/16/16 2:51 AM, Dave Wade wrote:
> http://www.vcfed.org/forum/showthread.php?55404-IBM-Displaywriter
> 
>  
> 
>  
> 
> Dave Wade
> 
> G4UGM & EA7KAE
> 
>  
> 

Re: An interesting use of the 4004 instructions

[Paul Koning]

> On Dec 15, 2016, at 2:52 PM, dwight  wrote:
> 
> I was looking at some disassembled 4004 code when I came across
> 
> a SKIP operation.
> 
> It isn't normally an instruction but If you do a JCN with all the  = 0,
> 
> it will do a NEVER jump.
> 
> This is the equivalent of a SKIP instruction.
> 
> I would suppose a JCN with  = $8000 would be an always jump,
> 
> on page ( not real useful as JUN takes the same cycles and space ).
> 
> I thought at first there was some errors in the code because there
> 
> were JMS to the middle of JCN instruction but then I noticed that there
> 
> were no conditions specified for the JCN. A little thought and I realized
> 
> it was a way to skip over a single byte instruction.

It's a bit like a coding convention I've seen used a lot in PDP-11 code, at 
least in some programs; RSTS/E is full of them.  Consider a function with two 
entry points, where Carry set or clear is used after entry to distinguish the 
two cases.  The two entry points look like this:

fun1:   tst (pc)+
fun2:   sec
; common code
bcs  case2
; case1...

Or a function that indicates a boolean result (say, success/fail) by Carry 
clear vs. set:

good:   tst (pc)+
fail:   sec
rts  pc

paul

DisplayWriter apparently on Craigslist...

[Dave Wade]

http://www.vcfed.org/forum/showthread.php?55404-IBM-Displaywriter

 

 

Dave Wade

G4UGM & EA7KAE