[cctalk] Re: FW: Re: ADM3a screen rot.

[Pete Turnbull via cctalk]

On 29/01/2024 20:45, William Sudbrink via cctalk wrote:

Sellam Abraham wrote:


I think you were fine.  That's how you discharge them anyway.  You
were just missing the grounding wire :)



I'd rather not be the electron sink In this case.  I've never taken a
hit off of a CRT have you?


Yes, from a 26" CRT in a colour TV.  It threw me across the room and
taught me a lesson I'll not forget.

BTW, if anyone has CRTs lying out of circuit, don't assume they're safe
either.  The EHT in normal use forces electrons into the glass, and when
disconnected they very slowly migrate back to the aquadag, producing a
substantial voltage.  I remember seeing this demonstrated on an
electronics course several decades ago.  Which is where I /should/ have
learned about discharging CRTs *through a suitable resistor* :-)

--
Pete
Pete Turnbull

[cctalk] Re: One of Paul Allen's Museums

[Pete Turnbull via cctalk]

On 24/04/2023 06:45, ED SHARPE via cctalk wrote:

Bad link  Zane I get a weird  screen from the timeEd#


Delete the strange character after the last "/" and it will work:

https://www.seattletimes.com/business/boeing-aerospace/after-3-years-flying-heritage-museum-to-reopen-in-everett/

--
Pete
Pete Turnbull

[cctalk] Re: flipchip cleaning and pin corrosion inhibition

[Pete Turnbull via cctalk]

On 23/04/2023 22:52, KenUnix via cctalk wrote:

Pete,

Did the 8E have core or solid state memory?


It had both, but I didn't put the core boards in the dishwasher.  I 
figured they might be too delicate for that, so I rinsed them by hand in 
the kitchen sink.


I should have said that in my original post.

--
Pete
Pete Turnbull

[cctalk] Re: flipchip cleaning and pin corrosion inhibition

[Pete Turnbull via cctalk]

On 23/04/2023 17:54, Fritz Mueller via cctalk wrote:


I’ve been eying the dishwasher, for the subset of flip chips that that are just 
DIP logic, carbon comp resistors, and ceramic bypass caps, anyway.   But I 
haven’t been brave enough to try that yet...  Most of the logic here has date 
codes to ’68 or ’69, so I’m inclined to treat it gently.  Any suggestions for 
approaches to clean this up?


I've used the dishwasher on a collection of PDP-8/E boards with success. 
 Avoid the hot drying cycle, and don't use a harsh dishwasher 
detergent; some are quite caustic.


--
Pete
Pete Turnbull

[cctalk] Re: WTB: Acorn A3010 or A4000

[Pete Turnbull via cctalk]

Hi, Ethan,

Whereabouts are you?  I'm in York, UK, and I have more than one spare 
BBC Micro. I don't have an A3010 but I do have an A3020 (red function 
keys) if that's of interest.


On 09/02/2023 16:13, Ethan O'Toole via cctalk wrote:


Looking for an Acorn A3010 or A4000 + KB/Mouse, happy to repair it.

Also Sinclair +3 with some disks
Also BBC Micro
Also Amstrad CPC 6128 color. Could forgo monitor and build my own PSU.


--
Pete
Pete Turnbull

[cctalk] Re: RQDX3's: Lessons learned.

[Pete Turnbull via cctalk]

On 04/02/2023 14:37, Glen Slick via cctalk wrote:

On 2023-02-03 22:48, Chris Zach via cctalk wrote:

Is it just the ROMs, or also some HW changes?
Do we have backup of the newer versions?


http://www.dunnington.info/public/DECROMs/
http://www.dunnington.info/public/DECROMs/ROMlist


It's just the ROMs, though IIRC there is a small difference in the 
meaning of one of the jumper settings.


And just an FYI for the list:  that domain came into existence amny 
years ago following a problem with my old ISP/website when it was taken 
over by another.  Partly as compensation, they provided that domain, but 
now it looks like it might be going away and I've had no luck with their 
tech support.  Again.  Sigh.  The data will be preserved and re-homed, 
maybe even expanded, but I don't know if the domain name will need to 
change.


--
Pete
Pete Turnbull

[cctalk] Re: SGI vs. Mac

[Pete Turnbull via cctalk]

On 24/12/2022 17:02, Chris via cctalk wrote:

  Don"t know what an Elan is. I do seem to recall suddenly an Indy with no 
graphics output, intended to be used as a headless server.


That was a Challenge.  the Indigo Elan is an Indigo with a particular 
higher-end graphics card.


I still have an Indy running 24/7, providing various services on my 
network.  It has 24-bit graphics and a 100baseT Ethernet interface, but 
it's not much used other than as a server these days.  Not the most 
efficient but somehow it's always seemed like more trouble to migrate 
things.


--
Pete
Pete Turnbull

[cctalk] Re: Whitechapel Computer Works

[Pete Turnbull via cctalk]

On 04/11/2022 17:47, Jonathan Katz via cctalk wrote:

Hi everyone!

I'm curious; other than Wikipedia what do we know about Whitechapel
workstations? Do any of us have some working in our collections, with
software, disk dumps, etc?


Jim Austin has 4 or 5 MG1s and a CG1 in his collection.
https://www.computermuseum.org.uk/


--
Pete
Pete Turnbull

[cctalk] Re: Flipping an 8" diskette

[Pete Turnbull via cctalk]

On 01/09/2022 14:31, Kenneth Gober via cctalk wrote:

On 5.25" diskettes punching a notch to enable use of the second side
worked due to 2 factors:

First, the index hole was commonly unused on 5.25" systems so it
didn't matter that the index hole was in the wrong place when the
diskette was flipped over.


It's my experience that the index hole is used, and does matter, on 
pretty much all 5.25" systems except Apple ][s.


--
Pete
Pete Turnbull

Re: Unrecognized DEC Power Supply in PDP-11/44 Configuration

[Pete Turnbull via cctalk]

On 02/12/2021 16:37, Josh Dersch via cctalk wrote:

On Thu, Dec 2, 2021 at 6:29 AM pbirkel--- via cctalk 
wrote:


Does anyone recognize the (presumably) DEC power supply on the front half
of the rack-bottom in the 11/44 listing at:



It's not a DEC power supply, it's a Fujitsu power supply, likely for an
M2284 SMD drive.  Probably went in the empty slot you mention below.


Yep.  Looks identical to the Fujitsu PSU in my 11/40 rack, and the rails 
are the same as my Fujitsu rails.


--
Pete
Pete Turnbull

Re: Setting up a VMS system

[Pete Turnbull via cctalk]

On 23/09/2021 14:23, Paul Koning via cctalk wrote:

On Sep 23, 2021, at 9:12 AM, Scott Quinn via cctalk  
wrote:
...
Isn't VMS DCL pretty close to RSX? Never used RSX, but that is what I
was always told.


I don't know how close it is to RSX, but I do know that RSTS (V9 and later) DCL 
was explicitly modeled on VMS DCL


RSX originally used MCR, but later (from about 3.2 IIRC) had DCL as an 
option, and that's where VMS DCL came from.


--
Pete
Pete Turnbull

Re: PDP-11/73 boot issues

[Pete Turnbull via cctalk]

On 21/09/2021 20:34, Chris Zach via cctalk wrote:

Can an MXV11 be used in a 22 bit system? I thought it was an 18 bit
device?


MXV11-B is 22-bit.  MXV11-A is 18-bit but supposedly can be used in a 
22-bit system if the RAM is disabled.


--
Pete
Pete Turnbull

Re: Unix or BSD for Dec PDP 11/34 and 11/45

[Pete Turnbull via cctalk]

On 17/09/2021 12:37, devin davison via cctalk wrote:


I'm working to get my pdp 11/34  and 11/45 running. I was curious what
versions of unix or bsd would work on the machines i have. I wanted to set
up  the systems with a bunch of dumb terminals and show them off at a local
maker fair.


7th Edition Unix would run on either machine, and will support multiple 
serial terminals.  BSD 2.11 needs split I/D space, which the 11/34 
doesn't have.



If possible too, id like to be able to telnet in to unix or bsd.I was also
curious if a ethernet interface exists for my unibus systems, or if i could
SLIP/PPP serial to another machine,so i could telnet in as well as use dumb
terminals.


7th Edition has no Ethernet/TCP/IP capability.  BSD 2.11 does.

--
Pete
Pete Turnbull

Re: 3d modelling software

[Pete Turnbull via cctalk]

On 23/08/2021 17:29, Rob Jarratt via cctalk wrote:

I think I may need to get a small part 3d printed (some plastic board
mounting guide rails from a PDP 11/24 H7140 PSU). What software is best for
a novice? Preferably free!


The hobbyist version of Fusion 360 is free.  It's what I use.  I've 
tried FreeCAD more than once but it still has some serious bugs. 
Tinkercad is also free but more limited and although it might be easier 
to get started with, it's more difficult to do some operations in.  I'd 
avoid Sketchup because it's renowned for producing faulty STL files 
unless you're careful.


If you want some help, you know I'm not very far away.  I can certainly 
I can test STL files out for you, and possibly even print some, 
depending on what they are.



--
Pete
Pete Turnbull

Re: Apple II PSU

[Pete Turnbull via cctalk]

On 10/05/2021 23:31, Adrian Graham via cctalk wrote:

Just me that reaches for a 2mm drill then?


Probably.  I usually use 3mm or 1/8".

I've taken more than one Apple PSU apart that way, long ago.

--
Pete
Pete Turnbull

Re: Hard To Believe This Person Is Serious

[Pete Turnbull via cctalk]

On 26/03/2021 09:15, Antonio Carlini via cctalk wrote:
This, for example, is clearly his last piece of "blanc" paper: 
https://www.ebay.co.uk/itm/Blanc-sheet-of-paper-04/254895244594 (or 
maybe it's French paper ...) :-)


Possibly a test post to check how the system works.  Years ago, eBay had 
a "test" category, for "items not for sale" or some such description. 
Anyone remember the "air guitar" that sold for something like $500?


--
Pete
Pete Turnbull

Re: FW: List your old computer

[Pete Turnbull via cctalk]

On 24/02/2021 23:02, stan via cctalk wrote:

By any chance, are you thinking of uptimes.net?
Some years ago (early 2000's?) it was tracking systems uptimes. I had an 
Alpha  system talking to it at one time.


IIRC, the record at one time was a VAX cluster, with an uptime of 1200+ 
days. Windows NT systems fared a lot worse, average of about 40 some 
days


I never got close to 1200 days, but I had an SGI machine at home talking 
to uptimes.net.  I remember watching it from work as it got close to 
1 hours (on the 416th day, 19th November 2002 according to syslog) 
when suddenly it went off the air.  It turned out the electricity 
provider had (accidentally) tripped the wrong breaker in the local 
substation.  Grr.


--
Pete Turnbull

Re: OT: pints, pounds (Was: APL\360

[Pete Turnbull via cctalk]

On 01/02/2021 20:24, Chuck Guzis via cctalk wrote:

Thank heavens that the Brits didn't come out with the 5150--we might
have had to deal with Whitworth (BSW) fasteners.


Nah, too many of them are similar to UNC/UNF, which would have just 
caused confusion.  We'd have used BA sizes.


--
Pete
Pete Turnbull

Re: OT: pints, pounds (Was: APL\360

[Pete Turnbull via cctalk]

On 01/02/2021 20:07, Fred Cisin via cctalk wrote:


A US pint of water weighs 1.043 pounds.
One "fluid ounce" (volume) of water weighs 1.043 ounces (weight)!


 That's also a US measure.  An imperial fluid ounce is 28.4ml and 
a floz of water weighs 28.4g, same as an avoirdupois ounce.  In fact 
it's defined (or was) as the volume of water that weighs one ounce.


--
Pete
Pete Turnbull

Re: UNIVAC

[Pete Turnbull via cctalk]

On 29/01/2021 15:51, Bill Degnan via cctalk wrote:

I have learned that Bakelite insulating is phenol and formaldehyde with
embedded asbestos.  Does anyone have any Bakelite insulation in any of
their vintage computers?


*Some* Bakelite contains asbestos.  The primary filler is commonly wood 
flour.  I worked with the Estates' asbestos team at a university and we 
found that a lot of Bakelite does not contain any asbestos.  The trouble 
is, you can't tell without proper analysis.


--
Pete
Pete Turnbull

Re: DEC PDP-8/E wanted

[Pete Turnbull via cctalk]

On 20/11/2020 16:55, ED SHARPE via cctalk wrote:


Go for a 8m or f  same omnibus and easer to lift as only onevnibuss panel!  -


Also a switchmode PSU which is much lighter than the -8/E linear supply.
But the -8/M normally has the minimal panel with the power key and 
minimal toggle switches.


--
Pete
Pete Turnbull

Re: Osborne 1 keyboard repair - success!

[Pete Turnbull via cctalk]

On 20/11/2020 17:59, Tom Hunter via cctalk wrote:

Hi Patrik,

As to the superglue - it was the only option because the prongs are just
melted flat. To get the key mechanism out or off I had to scrape all the
melted plastic off. I then subsequently re-attach the key mechanism to the
aluminium backing board by applying a tiny drop of superglue between what
was left of each prong and the associated hole in the aluminium backing
plate. The key mechanisms can be pushed out again with moderate effort if
it is ever necessary again.


Another way to do this is, or to repair any heat-staked plastic, is to 
use a cheap 3D printing pen with the sample ABS or even PLA filament 
they usually come with.


Lurid colours are optional with this technique ;-)

--
Pete
Pete Turnbull

Re: Firing up the pdt11

[Pete Turnbull via cctalk]

On 13/10/2020 22:28, Chris Zach via cctalk wrote:
Then I guess the question rattling around my brain is "How did I get 
this Elephant Memory systems disk formatted?"


RX01 format is a standard IBM format used by many systems, including 
many CP/M ones, so it was possible to buy pre-formatted disks.  Maybe 
they came that way.


I do have a card around here called an RXV21 from Plessy or something 
like that, maybe it could talk to an RX01 drive and format the disks?


Many 3-party controllers could.  Mine isn't a Plessey one, but it can do 
that - but mine connects to standard SA800-style drives, not an RX02.  I 
also have a Baydel F311 controller, which also can format disks and 
connects to standard SA800-style drives, but it only does single density.


--
Pete
Pete Turnbull

Re: Osborne 1 keyboard repair?

[Pete Turnbull via cctalk]

On 21/09/2020 12:41, Tom Hunter via cctalk wrote:

The problem I am seeing is that 3 keys ("h", "j" and "y") are permanently
pressed.


I'm not familiar with this keyboard, so despite having fixed lots of 
other types, what I'm about to write is no more than musing and may be 
inapplicable drivel, but...


A friend once spilled a glass of wine into his keyboard and had a 
similar problem.  I've seen the same from a cola spillage.  Washing it 
fixed it.  Can you see if there are any spillage residues in there?  IPA 
isn't always better than water and detergent - though you might want to 
use it as a water removal agent afterwards.


As I imagine you've already realised, the keys are adjacent and likely 
share a track.


I looked at the pictures.  Can you get at the other side of the circuit 
board?  If the it's fibreglass or even SRBP with copper tracks, maybe 
you can get at the tracks to the 'h' etc keys and cut them with a 
scalpel or craft knife to isolate them to see where the resistance 
really is.  Before cutting anything, obviously make sure you can get a 
soldering iron in there afterwards to bridge the cuts.


--
Pete
Pete Turnbull

Re: Synchronous serial Re: E-Mail Formats RE: Future of cctalk/cctech

[Pete Turnbull via cctalk]

On 18/06/2020 21:31, Paul Koning via cctalk wrote:


I did see something vaguely similar.  Bell 202 modems are 1200 baud FSK, so on 
a voice channel they normally are 1200 bps half duplex.  They can also be 
hooked up to 4-wire fixed circuits.  But they have a reverse channel, good for 
150 baud if I remember right.


IIRC the Bell standard allows for only 50 baud and the back channel uses 
ASK (basically switching a carrier on and off).  The CCITT equivalent 
standard is 1200/75 baud, FSK both ways, and in the 1980s and early 90s 
that was used for Prestel and similar systems, including Micronet, 
Telecom Gold email, Packet SwitchStream (PSS), BT Tymnet and some online 
banking systems, here in the UK.  It was also used for Minitel in 
France, BTX in Germany and later for Telidon in Canada.  Some of the UK 
banking systems like HOBS survived using viewdata that way up to the end 
of the 1990s, and I still have at least a couple of 1275 modems.


The idea was to use 1200 for the transmission from central computer to 
consumer, and the back channel for user responses/commands.   Not many 
people type faster than 7.5cps.


--
Pete
Pete Turnbull

Re: mail on spool as G-d intended was Re: Future of cctalk/cctech

[Pete Turnbull via cctalk]

On 18/06/2020 23:03, Eric Korpela via cctalk wrote:

I used to use netcat, but now I just watch an oscilloscope.


Reminds me of a cartoon in a HiFi mag several years ago.  Enthusiast 
talking to friend in front of dual 'scopes, "Why listen to it when I can 
see it's perfect?"


--
Pete
Pete Turnbull

Re: Microsoft open sources GWBASIC

[Pete Turnbull via cctalk]

On 27/05/2020 11:55, Peter Corlett via cctalk wrote:

It's better now, though. Price differences can be explained by delivery costs,
import duties, and VAT/sales tax. And in the case of 1977, middlemen who
exploit the difficulty in importing stuff oneself.

The USA is some sort of gravity well when it comes to postage. It's cheap-ish
to send stuff to it, but unreasonably expensive to send stuff from there. So
for a product actually made in the USA, USPS, UPS, etc all conspire to ratchet
the price up.


Very often, yes.  I see that most notably when I look at huge shipping 
charges for stuff on eBay.co.uk or from the Global Store as seen on 
Amazon.co.uk.  Yet it's not always the case.  Recently I needed a part 
for a Weller soldering station originally bought from Farnell in the UK. 
 They're a Weller agent, only a few tens of miles from where I live, so 
the logical place to look.  Nevertheless, it was almost 40% cheaper to 
buy the part from Digikey, including UPS shipping from Texas to my 
address in the the UK, where it arrived in 36 hours.


--
Pete
Pete Turnbull

Re: Keyboard inverters/converters for terminals

[Pete Turnbull via cctalk]

On 22/05/2020 17:21, Fred Cisin via cctalk wrote:
#> 3.0" drives (Amdek, Amstrad, etc.) use same connectors as "standard"
5.25", with "molex" power connector (I don't know what the CORRECT name 
is for that connector).




It's part of the AMP (now TE) Mate-N-LOK series.

But, I have some 3.25" drives that use same connectors as "standard" 
3.5" drives, ("4 pin Berg"?)  EXCEPT 5V and 12V are swapped in their 
positions in the coneectors!


Not Berg, not even the same pitch.  They're AMP Economy Interconnect 
connectors, with a 2.50mm pitch.




--
Pete
Pete Turnbull

Re: DEC QBUS Backplanes

[Pete Turnbull via cctalk]

On 17/04/2020 17:52, Bill Gunshannon via cctalk wrote:


I found a backplane.  It says
Digital on it but does not  have an H- number.  I also
don;t find it listed in any  of the lists I can find on
the web.

It has 8 A-B slots and 4 C-D slots.  the Four C-D are on
the bottom half of the backplane.  I am assuming it is
18 bit and the C-D were intended for things like the 2
board RL controller.


Is it quad height or hex height?  Is there a picture anywhere?
It sounds a bit like an H9278-A, which is a 22-bit 4 x 8 (ie quad 
height, 8 rows) backplane for a BA23 box.  That has a mixture of Q22 and 
CD in part and Q22 on the rest, but the rows with CD are the top rows.


http://www.dunnington.info/public/PDP-11/QBus_chassis

--
Pete
Pete Turnbull

Re: OT: Weller soldering irons

[Pete Turnbull via cctalk]

On 06/04/2020 00:22, Jon Elson wrote:

On 04/05/2020 03:32 PM, Pete Turnbull via cctalk wrote:
A few hours ago I started looking at three "smart" light switches that 
need LEDs replaced, and switched on the soldering iron, and ... nope. 
It's a Weller WP80 and it seems the sensor in the heating element has 
died.



Is the sensor a separate component?


Sadly, no.  That's the first thing I thought of.  The heater and sensor 
are integral with the stainless steel shaft and I can't see any way to 
get them out without destroying the shaft.


--
Pete
Pete Turnbull

OT: Weller soldering irons

[Pete Turnbull via cctalk]

A few hours ago I started looking at three "smart" light switches that 
need LEDs replaced, and switched on the soldering iron, and ... nope. 
It's a Weller WP80 and it seems the sensor in the heating element has 
died.  I discovered that only after resetting and then dismantling the 
control unit to check it out with a DVM, of course.


Clearly I need either a new WP80 element, or a new soldering iron.  I 
could get a WSP80 for far less than the cost of a new element for the 
WP80, but I'd get the element faster.  So which, if any, is the better 
iron?  What would you guys do?


I begrudge paying UKP 92 for a new element.  That's the cheapest I could 
find -- /half/ the most expensive price -- but just seems ludicrously 
extortionate for what amounts to a piece of swaged stainless steel tube 
with a short length of resistance wire and an even shorter length of 
thermocouple wire inside it.  I could buy a whole new solder station 
with more bells and whistles, albeit of a "lesser brand", for less.


--
Pete
Pete Turnbull

Re: Design flaw in the SCSI spec?

[Pete Turnbull via cctalk]

On 08/01/2020 18:06, Paul Koning via cctalk wrote:


Allowing accountants to do electrical engineering makes just as much
sense as allowing sociologists to do brain surgery.


Off topic, but allowing accountants to do accountancy isn't always much
better.

I recall the Christmas when our accountant insisted on an inventory of 
the electronics repair workshop.  We kept our small components in a bank 
of drawers some 1.5m (around 5 feet) wide by about 1m (3 feet or so) 
high.  Each drawer is just over 50mm (2") by 50mm.  A drawer would hold 
several tens of 1/10W resistors, or some loose transistors or 
capacitors, or half a dozen ICs, or...  And he wanted each one counted. 
 And a cost given for each single item.  And insisted that estimates 
were unacceptable for either count or cost.


A few years later, when the company was about to be wound up, a 
colleague and I bought the bank of drawers and several other items for £100.


--
Pete
Pete Turnbull

Re: Two dead LK201 keyboards

[Pete Turnbull via cctalk]

On 28/12/2019 01:46, Paul Koning via cctalk wrote:


I can get one and test it with an Apple keyboard, but that doesn't sound right. 
 There aren't enough wires on a USB connector to allow you to speak the PS/2 
protocol.  And there are PS/2 to USB adapters (for old keyboards) that are the 
same size; clearly the old keyboards don't speak USB.


Enough wires?  +5V, ground, clock, data vs +5V, ground, D+, D-

Those old adapters are definitely just passive wiring, and were commonly 
supplied with dual-standard mice.  That's why they're green.  I worked 
in the IT department of a large university and it caused a lot of 
confusion back in the day when they were common, when people expected 
them to convert any keyboard or mouse to PS/2, and found they didn't. 
They only work with devices that inherently support both protocols.


--
Pete
Pete Turnbull

Re: Introduction and need help bringing some pdp11's back

[Pete Turnbull via cctalk]

On 29/10/2019 16:28, Chris Zach via cctalk wrote:
The real problem is I'm trying to put an RQDX3 in there instead of the 
ESDI controller so I can boot off RX50's. And I have no idea which way 
all the various ribbon cables are supposed to go. Will any 50 pin cable 
work between the RQDX3 and the BA23 distribution bulkhead? Anything 
special about the 34ish pin cable that goes between the bulkhead and the 
RX50? So far when I try to boot all devices DU0-3 give me not yet ready.


Welcome back!

No, there's nothing special about either the 50-way ribbon cable or the 
34-way ribbon cable.  Just don't use a PC-style floppy cable with a 
twist in it.  DEC did it the way God (and Alan Shugart) intended.  But 
which distribution bulkhead have you got?  I assume not an M9058, 
because that's a card with lots of options that goes in a Q-bus 
backplane and wants jumpers setting.


Either way, you might find this file helpful if you want to work out 
what's going where:

http://www.dunnington.info/public/RQDX/RQDXn_pinout.pdf
and maybe even a glance at this one:
http://www.dunnington.info/public/RQDX/M9058_schematic.pdf
because it shows the relationship between the connectors and the signals 
a bit better.


--
Pete
Pete Turnbull

PDP-8/E MM8-E jumper settings

[Pete Turnbull via cctalk]

I've lost track of where the jumper settings are documented for the
MM8-E, and I've got five sets here that have all been changed one way or 
another.  Can anybody remind me where to find the settings for the three 
EMA jumper links on the G111? I want to set at least one board set to 
the lowest bank.


--
Pete
Pete Turnbull

Re: Cleaning an old keyboard

[Pete Turnbull via cctalk]

On 25/09/2019 16:29, Noel Chiappa via cctalk wrote:


If the reference is to:

 Lloyd S. Swenson, James M. Grimwood, Charles C. Alexander; "This New
Ocean: A History of Project Mercury"; SP-4201; NASA; Washington; 1966


It is indeed in that.  My copy isn't to hand and if it's not indexed 
then it would take a while to find, but that's where I first saw it. 
I'm pretty sure it's documented elsewhere too.


--
Pete
Pete Turnbull

Re: Cleaning an old keyboard

[Pete Turnbull via cctalk]

On 24/09/2019 07:30, Philip Belben via cctalk wrote:

PS I wish people wouldn't say WD40 is not a lubricant.  It is.
The problem is that it is quite a heavy grease - suitable for (say) door hinges 
- but when it comes out of the can it looks like a fine oil


I do wish people wouldn't say WD40 is a lubricant.  It's not.  It's a 
solvent - a light paraffin - carrying a small amount of wax - not grease 
- and was designed as a water displacer based on a degreaser.  This is 
documented in NASA's official history of Project Mercury, for which it 
was invented.  Try lubricating your fan bearings or bicycle chain with 
it and see how much it shortens the life, as it washes out the proper 
lubricant, as it's supposed to do.


--
Pete
Pete Turnbull

Re: RSTS collection in the UK

[Pete Turnbull via cctalk]

On 27/06/2019 07:53, Dave Wade wrote:

Pete,

  Am I right in thinking Jim has no scanning facilities, and access is still 
one weekend in two.


Pretty much.

--
Pete
Pete Turnbull

Re: RSTS collection in the UK

[Pete Turnbull via cctalk]

On 26/06/2019 22:52, Al Kossow via cctalk wrote:


On 6/26/19 1:00 PM, Dave Wade wrote:

Could we forward to the UK DecTech list?


Let's see if Pete Turnbull is able to make contact


I have, but I've not yet made any arrangement to collect it all.  It 
could be postponed until late July as the donor will be away, so there's 
time to arrange something if anyone can.


--
Pete
Pete Turnbull

Re: RSTS collection in the UK

[Pete Turnbull via cctalk]

Hi, Al.

This sounds slightly familiar - Jay contacted me a year or two ago about 
a similar lot but the donor never got back to me.


Anyway, I would be happy to collect these on behalf of Jim Austin, for 
the Computer Sheds:  http://www.computermuseum.org.uk/
We'd be particularly interested in the RSTS stuff, as we have very 
little of that.


Please pass on my contact details.

On 25/06/2019 17:20, Al Kossow via cctalk wrote:

We received this offer, it probably makes more sense for someone in the UK to 
get the lot.
Is there someone at a collecting institution that would like to take this on? 
Email me and
I can forward your contact information to them.

"I have a few disk packs available if you need them. (Please note I am in the 
UK). I also have a range of PDP-11
interface boards, a mix of dual, quad and Unibus. Is there anything in 
particular that you need? Finally I have a mass
of RSTS related documentation, such as one copy of every edition of the US 
publication RSTS Porfessional magazine. Plus
copies of RSTS and RT-11 operating system manuals, from RSTS Version 4a (1974) 
through to Version 10.1 (mid 1990s)."




--
Pete
Pete Turnbull

Re: Network cards and Win98SE

[Pete Turnbull via cctalk]

On 14/05/2019 14:17, John Foust via cctalk wrote:

At 03:02 AM 5/14/2019, Christian Corti via cctalk wrote:

On Mon, 13 May 2019, Grant Taylor wrote:

"Gaming adapters" take a wired computer and connect it to a wireless network.


That "adapter" has always been called a WLAN or wireless bridge.


I've known the term "gaming adapter" because I knew it was the common
name for what I'd call a dedicated wireless network bridge.  Just another
fine example of how gaming has come to dominate parts of the computer world.
They who sell the most get to name the thing.


But they probably don't.  Almost every smart TV and settop box 
manufacturer sells a wired-to-wireless bridge dongle, and I'd bet there 
are more "wireless adapters" or "network adapters" sold for that purpose 
rather than gaming, simply because TVs, settop boxes and DVD/BluRay 
players outsell gaming machines.  And then there are the slightly more 
sophisticated/robust ones sold by the likes of 3Com and Cisco, which 
I've never seen called anything other than a "wireless bridge".


There are two or three groups at my university who regularly organise 
gaming parties, or sometimes called "LAN parties" here, and plenty of 
ad-hoc groups who also do so since the word got round that IT Services 
was willing to provide some support for them.  I've never heard the term 
"gaming adapter" from them.  Perhaps it's a piece of localised jargon. 
The AV Services department, who use quite a lot of them for large TV 
screens in lecture theatres, for remote lectures, teleconferencing, as 
bulletin boards, etc always call them "wireless adapters" or sometimes 
"network adapters".


When "gaming adapter" was first mentioned, one of the first things that 
came to mind was the joystick-shaped gadget that fits over a keyboard to 
press the up/down/left/right keys when you waggle it.  Searching "gaming 
adapter" throws up a lot of USB wireless dongles before wired Ethernet 
ones.  I don't really care what you or Grant call it yourself, but at 
best the term is confusing, given it can mean at least two other things, 
and it's certainly not any sort of canonical name as has been suggested.


--
Pete
Pete Turnbull

Re: Network cards and Win98SE

[Pete Turnbull via cctalk]

On 13/05/2019 23:47, Grant Taylor via cctalk wrote:

On 5/13/19 3:58 PM, Chuck Guzis via cctalk wrote:
I don't want to get into a long discussion; I merely wanted to point 
out that you're unlikely to find the term "gaming adapter" in Linux 
tech docs as they're not written for that audience. 


You /might/ not find the term in a Linux tech doc.  But I'd be somewhat 
surprised if you didn't.


Hmm.  I've been a network manager for over 20 years, supporting tens of 
thousands of staff and students at a university where there's a lot of 
gaming activity and I've never heard the term gaming adapter before.


The term could mean many things...

> The first eight hits on a google search for "gaming adapter" are
> directly relevant.

The first few hits I get refer to a USB device to connect to a console 
to give it WiFi capability.  That's not what Charles described, and what 
you referred to, which is a network bridge.


--
Pete
Pete Turnbull

Re: TMSCP docs?

[Pete Turnbull via cctalk]

On 13/05/2019 08:51, Matt Burke via cctalk wrote:


The protocol specification for MSCP and TMSCP is available here:

http://www.bitsavers.org/pdf/dec/dsa/mscp/

You might also want to look at the implementation of MSCP and TMSCP in Simh:

https://github.com/simh/simh/blob/master/PDP11/pdp11_rq.c
https://github.com/simh/simh/blob/master/PDP11/pdp11_tq.c


Not so useful for tape, but the original MSCP reference which Josh 
referred to, the "UDA50 Programmer's Documentation Kit" (QP-905-GZ 
comprising AA-L619A-TK, AA-L620A-TK, AA-L621A-TK), is on Bitsavers at

http://www.bitsavers.org/pdf/dec/disc/uda50/
and at
http://www.dunnington.info/public/MSCP/

--
Pete
Pete Turnbull

Re: RT-11 doesn't recognize my 3.5" floppy

[Pete Turnbull via cctalk]

On 06/05/2019 23:38, John Forecast via cctalk wrote:

The release notes on bitsavers indicate that the RX33 was not supported until 
RT-11 V5.04.



On May 6, 2019, at 6:20 PM, Charles via cctalk  wrote:

I have installed an RQDX3



But, when I boot the system (with RT-11SJ V5.01), it can't see the drive at all.


Not only was the RX33 not supported until 5.04, there's a bug in the 
MSCP DU driver that wasn't fixed until 5.03 (IIRC) or maybe 5.04, which 
means nothing on an RQDX3 can be guaranteed to work properly before 
that.  It caused me a lot of grief, way back in 1994.


See the files at http://www.dunnington.info/public/RQDX/ and 
particularly http://www.dunnington.info/public/RQDX/DUX.TXT if you're 
interested.


--
Pete
Pete Turnbull

Re: Service for converting CD-ROMs into ISO files?

[Pete Turnbull via cctalk]

On 04/05/2019 21:36, Dave Wade via cctalk wrote:

Paul,
VAX CD-ROMS generally are not ISO. ISO implies the ISO9660 file system, but 
many VAX CD ROMS are in native VMS Files-11 format.
Some Windows utilities don't handle these so you need third party software to 
create an image of these CD's.
Generally it has a .iso extension but as the content is not ISO9660 you can't 
mount it on Windows or Linux.


Indeed, and the same is true of IRIX install CDs, which have an EFS 
filesystem.


--
Pete
Pete Turnbull

Re: RS2030 MIPS workstation

[Pete Turnbull via cctalk]

On 04/05/2019 01:54, Al Kossow via cctalk wrote:


I see we all were talking about the M2030 around 3 years ago
http://www.classiccmp.org/pipermail/cctech/2016-May/017829.html


Some useful information in there, but I have the original MIPS keyboard 
and mouse.


--
Pete
Pete Turnbull

Re: RS2030 MIPS workstation

[Pete Turnbull via cctalk]

On 04/05/2019 02:54, Al Kossow via cctalk wrote:

On 5/3/19 3:22 PM, Pete Turnbull via cctalk wrote:

Anyone know much about early MIPS workstations?


RISCos 4.52 src, incl monitor src up now under
http://bitsavers.org/bits/MIPS/RISCos


Once I can get the machine to stop wailing, that will be useful!

--
Pete
Pete Turnbull

Re: RS2030 MIPS workstation

[Pete Turnbull via cctalk]

On 04/05/2019 01:04, Al Kossow via cctalk wrote:



On 5/3/19 4:25 PM, Al Kossow via cctalk wrote:


So I'd like to know what the RAM spec really is, whether I need to reprogram 
the Dallas chip (and if so what goes
where), and what the diagnostic numbers on the internal LED mean.  Anyone?



I thought I threw them all away, but i just found two 3020s and a 2030 with a 
full set of SIMMs
which seems to get through POST. Will try dumping the NVRAM


Thanks - that would be very useful, if you have time and suitable 
hardware.  I read the pages at geekdot.com a couple of weeks ago, but 
I'd not seen the MAME data.  I did find a manual about the ROM on 
Bitsavers recently, so with that ans the MAME info I can probably work 
out what some of those settings should be if necessary.  Sadly nothing 
I've found says anything about the internal LED display, but my 
suspicion is that the error is to do with bad RAM.


--
Pete
Pete Turnbull

RS2030 MIPS workstation

[Pete Turnbull via cctalk]

Anyone know much about early MIPS workstations?  I'm trying to get a 
MIPS RS2030 to boot, without much luck so far.  It goes through the 
selftest but stops with the internal LED display at "5" accompanied by a 
continuous beep.


Known problems:

- The Dallas DS1287 battery is flat; I can hack a 3V lithium onto that. 
I assume it should still work to some extent even if the contents are lost?


- The RAM is highly suspect.  I think it needs a minimum of 8MB to start 
up.  It has a good complement of SIPPs, but some of them are definitely 
non-original and are actually 30-pin SIMMs that somebody has done a 
rubbish job of soldering short stiff wires onto.


So I'd like to know what the RAM spec really is, whether I need to 
reprogram the Dallas chip (and if so what goes where), and what the 
diagnostic numbers on the internal LED mean.  Anyone?


--
Pete
Pete Turnbull

Re: Mounting HP7970e 9-Trk 1/2" Tape Drive

[Pete Turnbull via cctalk]

On 05/02/2019 20:59, Chuck Guzis via cctalk wrote:

On 2/5/19 12:19 PM, Jack Harper via cctalk wrote:



I learned that very quickly - If you open the front of the Drive and
swing out the door with the electronics, drive motors etc, it is
definitely heavy enough to tip a rack.

I bolted the destination 19" rack down to the concrete floor with 3/8"
bolts.  It will not, I hope, soon go anywhere.


After struggling years earlier with getting a Fujitsu drive into a rack
by my lonesome, I was determined not to repeat the process. The rack,
VTW, is from an old HP Storage Array, which has a nice anti-tip pullout
on the bottom.

I constructed a dolly for the HP drive that allows me to roll it around
where I need it. It's low enough that it can slip under a table.


Some years ago, Jay recommended a Genie Load Lifter to me (thank you!), 
and I was fortunate enough to get two of them as "new old stock" for 
about half price.  They're relatively inexpensive and absolutely 
invaluable.  Put a 200lb unit into the top of a full height rack?  No 
problem.  Shame I had to leave both behind when I left that employment 
(especially since they bought a third one but never used it)!


--
Pete
Pete Turnbull

Re: PDP-11 Memory

[Pete Turnbull via cctalk]

On 12/01/2019 17:39, Bill Gunshannon via cctalk wrote:


One confusing part of this.  Everything I have read today
seems to say that the only difference between the 11/73
and the 11/83 in a MicroPDP-11 was the memory used.
QBUS = 11/73
PMI = 11/83

Is this correct or not?


No, not really, but sort of.  Originally, the J11 chip was available in 
15MHz and 18MHz versions.  The 15MHz chips were used for 11/73 systems 
and the 18MHz ones for 11/83 systesm.  To emphasise the difference, they 
had slightly different boot ROMs, and the 11/73 systems were shipped 
with QBus memory while the 11/83 systems were shipped with PMI memory, 
which is faster.  So a factory-fresh 11/73 was always 15MHZ + QBus 
memory, whereas a factory-fresh 11/83 was always 18MHz with PMI memory, 
and significantly faster.  In fact the PDP-11 and Hardware Help lists on 
DECUServe were full of people discussing the difference as many people 
didn't believe that you could use PMI memory with the processor from an 
11/73 (you can), while others insisted that if you changed the memory an 
11/73 became exactly an 11/83.  In fact the XXDP diagnostics and RT-11 
differentiate 11/73 from 11/83 purely on the basis of PMI memory detection.


The J11 chip used on those systems was supposed to run at 20MHz or so 
from day one, but it didn't quite make it.  Some, especially early on, 
would only run fully reliably at 15MHz, hence the above.  I've got a 
later one in an 11/83 running at 20MHz, though.  It doesn't gain an 
awful lot, but I changed the crystal, just because I could.


--
Pete
Pete Turnbull

Re: PDP-11 Memory

[Pete Turnbull via cctalk]

On 12/01/2019 01:24, Zane Healy via cctalk wrote:


I’m pretty sure you could get the /23+, /53, /73, /83, and /93 in either a BA23 
or a BA123.  I have an actual badged BA23 pedestal for my /23+.


I'm fairly certain all microPDP-11/23+ systems were only sold in BA23 
boxes, and I think microPDP-11/73 and the later, cheaper, cut-down 11/53 
were as well.  But almost all the 11/83 systems I've ever seen were in 
BA123 boxes, though they did sell some in BA23 pedestals - I've got one.


--
Pete
Pete Turnbull

Re: PDP-11 Memory

[Pete Turnbull via cctalk]

On 11/01/2019 23:58, Ethan Dicks via cctalk wrote:

On Fri, Jan 11, 2019 at 3:51 PM Bill Gunshannon via cctalk
 wrote:

Mine are all BA23.  Wasn't the BA123 for the MicroVAX?


As sold, most likely.  I don't think DEC ever configured any MicroPDP
systems in a BA123 but no reason it doesn't work.


Absolutely not so - there were very many microPDP-11/83 systems sold in 
BA123 cabinets, in fact probably more in BA123 than in BA23.  The 
MicroPDP-11 System Maintenance Manual features the BA123 heavily 
throughout, as do other microPDP-11 manuals.


--
Pete
Pete Turnbull

Re: PDP-11 Memory

[Pete Turnbull via cctalk]

On 11/01/2019 19:59, Bill Gunshannon via cctalk wrote:


MicroPDP box has first three slots A-B-C-D to support PMI
memory and the rest are serpentine A-B.

Even giving a bus grant problem, I can't see that causing a CSR
error.  I will probably have to dig out another box this weekend
just to be sure there isn't a problem with the backplane.


Without knowing exactly what cards you've got in there, it's hard to 
tell.  There are quad-height cards that work only in straight (A.B.C.D) 
backplanes/slots, and quad cards that work in either straight or 
serpentine. There are cards that use or expect (or won't permit) certain 
signals on some pins which work fine in 18-bit backplanes but not 
22-bit.  There are things that will work in a BA11-S with H9276 
backplane (which is what you had, if it really was a PDP-11/23plus) but 
not a BA23.  You probably need to make a list of what you're using and 
check through the relevant Micronotes about compatibility.


BTW, BA23 and BA123 microPDP-11 backplanes aren't the same - it's the 
first 4 slots that differ in a BA123, and slot 13 is different again. 
Take a look at http://www.dunnington.info/public/PDP-11/QBus_chassis


--
Pete
Pete Turnbull

Re: Bogus "account hacked" message

[Pete Turnbull via cctalk]

On 08/01/2019 21:37, alan--- via cctalk wrote:


There is a special place in hell for spammers.  There is an even more 
special place lower in hell for web site builders that store plain-text 
passwords rather than a one-way salted hash of a password.


Oh, there's a worse hell -- I hope -- for the sort of Unix sysadmin (I 
won't mention Aaron's name ;-)) put in charge of a sizeable HPC cluster, 
decided to password protect it to ensure only a certain set of users 
would have access, somehow copied the passwords they used on the main 
system, and stored them in plain text on a related machine for his 
access control.


He no longer works for the enterprise in question.

--
Pete
Pete Turnbull

Re: PDP-8/e

[Pete Turnbull via cctalk]

On 08/12/2018 09:55, Rod G8DGR via cctalk wrote:

Nice try Josh - close – you  have to change the crystal first and you can’t get 
them.


Both Farnell and Mouser UK have suitable crystals.  They don't have to 
be the same physical size.  I've changed several.


--
Pete
Pete Turnbull

Re: PDP-8/e

[Pete Turnbull via cctalk]

On 07/12/2018 17:46, Jon Elson via cctalk wrote:

On 12/07/2018 11:38 AM, Rod G8DGR via cctalk wrote:

Oh good how do you set them to 110 baud?

Oh, WOW!  Good catch, it only goes down to 300 baud!  major screwup, 
ought to be reported to the developers.


But wouldn't it be better to set the serial card in the PDP-8/E to 
something faster anyway?  Although on one of the serial cards, that 
requires a crystal change, so though commonly done, may not be practical 
for Rod.


--
Pete
Pete Turnbull

Re: PDP-8/e

[Pete Turnbull via cctalk]

On 07/12/2018 17:44, Jon Elson via cctalk wrote:

On 12/07/2018 11:22 AM, systems_glitch via cctalk wrote:

Indeed, unless you need character pacing.


Actually, with the correct settings of the serial port (xon/xoff or CTS 
pin) the serial port driver should do this, too, so cat would work.


A PDP-8/E doesn't have a CTS pin and the loaders don't support XON/XOFF, 
though.


--
Pete
Pete Turnbull

Re: PDP-8/e

[Pete Turnbull via cctalk]

On 07/12/2018 17:22, systems_glitch via cctalk wrote:

Indeed, unless you need character pacing.

Thanks,
Jonathan


That's just what I was going to say :-)  And also provided you remember 
which entry in /dev to redirect cat's output to, and what arcane stty 
command you need to set baud rate and word size on that, and that you 
have already edited the leader, trailer, and any junk off the tape file 
you downloaded from the 'net :-)



On Fri, Dec 7, 2018 at 12:13 PM Guy Sotomayor Jr via cctalk <
cctalk@classiccmp.org> wrote:


I just use ‘cat’.  Seems to work fine.  ;-)

TTFN - Guy


On Dec 7, 2018, at 4:57 AM, Pete Turnbull via cctalk <

cctalk@classiccmp.org> wrote:


On 07/12/2018 09:59, Rod G8DGR via cctalk wrote:


OK now I need a little help.
Does anybody know of a terminal emulation program that will simulate

the reader on an ASR33?

I know about   RIM and BIN loaders but how and what to feed them I have

long forgotten


For a Unix or Linux machine, there's send and rsend, and several other

utilities, that you can find at Kevin McQuiggin's web page:

http://highgate.comm.sfu.ca/pdp8/
and on mine:
http://www.dunnington.info/public/PDP-8/

--
Pete
Pete Turnbull






--
Pete
Pete Turnbull

Re: PDP-8/e

[Pete Turnbull via cctalk]

On 07/12/2018 09:59, Rod G8DGR via cctalk wrote:


OK now I need a little help.
Does anybody know of a terminal emulation program that will simulate the reader 
on an ASR33?
I know about   RIM and BIN loaders but how and what to feed them I have long 
forgotten


For a Unix or Linux machine, there's send and rsend, and several other 
utilities, that you can find at Kevin McQuiggin's web page:

http://highgate.comm.sfu.ca/pdp8/
and on mine:
http://www.dunnington.info/public/PDP-8/

--
Pete
Pete Turnbull

Re: [rescue] Sun2/120 SunOS 3.2 suntools movie

[Pete Turnbull via cctalk]

On 06/12/2018 12:28, Liam Proven via cctalk wrote:

Looking up the SUN-1, I see that it lacked a graphics adapter, and was
a text-only machine. I didn't know that. That alone means that it's
not really what I think of when I think of a Sun workstation: no
windowing system means that for me it's not really a workstation.


That's simply not true.  The first Sun 1 was actually designed as a CAD 
system, and did indeed have graphics.  *Does* have graphics, I should 
say, as I've seen it.


--
Pete
Pete Turnbull

Re: [rescue] Sun2/120 SunOS 3.2 suntools movie

[Pete Turnbull via cctalk]

On 06/12/2018 11:44, Tony Duell via cctalk wrote:

On Thu, Dec 6, 2018 at 11:19 AM Liam Proven via cctalk
 wrote:

On Wed, 5 Dec 2018 at 23:12, Chris Hanson  wrote:


It’s a Sun-2 so it’s not really arguable whether it’s the first ever Sun 
workstation: It’s not.



But I am mildly curious what your definition of a Sun workstation is,
if it excludes a 680x0 machine with Unix and a big monochome bitmap
display...

I don't think anyone is questioning that it's a workstation, and that it was
made by Sun.

I think the problem is over 'first' and that a Sun-2 is not going to be the
'first' model.


Particularly since I know someone, not far from here, who has a Sun 1.

--
Pete
Pete Turnbull

Re: George Keremedjiev

[Pete Turnbull via cctalk]

On 21/11/2018 22:46, Bill Gunshannon via cctalk wrote:


On 11/21/18 5:19 PM, Fred Cisin via cctalk wrote:

Ed,
It is YOUR mail program that is doing the extraneous insertions, and
then not showing them to you when you view your own messages.

Seriously, YOUR mail program is inserting extraneous stuff.
Everybody? but you sees it.



I don't.  I didn't see it until someone replied with a
copy of the offending text included.


I see the extra spaces, which are non-break spaces.  I think the reason 
John was seeing uppercase A-circumflex characters is because Ed's email 
is using UTF-8; however John's email client isn't respecting the header 
that says so, and is using Western (ISO-8859-1).  NBSP in UTF-8 is 
A-circumflex in Western.


Amusingly, Bill's reply also contains a NBSP (after the full stop in 
"don't".), which displays as A-circumflex when I change the coding in my 
client.


--
Pete
Pete Turnbull

Re: Large Collection Of Dec/Digital PDP Documentation

[Pete Turnbull via cctalk]

On 06/11/2018 21:45, Zane Healy via cctalk wrote:

On Nov 6, 2018, at 10:57 AM, Brian L. Stuart  wrote:





Isn't RT-11 V4 orange?  I'll have to check when I get home, but
I'm pretty sure that's the set I have.  (That and a blue binder set
for V3 and a loose set of V2.)



You might be right, my v3 & v4 sets went up to Paul Allen’s museum, I kept the 
v5.x set.

V3 was definitely dark blue.


Interesting.  My sets of RT-11 V4.0 are all dark blue.  The only V3 I've 
seen is light blue.


--
Pete
Pete Turnbull

Re: Single-height Qbus grant continuity PCB

[Pete Turnbull via cctalk]

On 14/08/2018 16:52, Tony Duell via cctalk wrote:


But I have here a little square board (the same size as the older
Unibus grant continuity card) with just 2 pairs of pins linked. In
the etch is a Digital logo (so I assume it's a real DEC product) and:

LSI11 Grant Continuity G7272 5012564B Side 2

Has anyone come across that one before?


No, not seen one of those.  Not sure I want to, either: I like to keep 
the skin on my knuckles ;-)


--
Pete
Pete Turnbull

Re: Needing help fixing an irix boot disk

[Pete Turnbull via cctalk]

On 05/07/2018 10:08, Mazzini Alessandro via cctalk wrote:


Long story short, a while ago I cloned the hd of a Fuel I got given (6.5.16, 
original installation from an iconic car designer, Bertone), and all was ok. 
The original hd was then left in place but unpowered, the cloned was upgraded 
to 6.5.22 to maintain the classic applications.



getting more puzzled... the boot drive appeared readable, so why the scsi hard 
errors.

Then I simply reconnected the original hd, and from that one boots with no 
issues... result, probably the last or both shutdowns while the Audigy was 
plugged were not so clean.



Bottom line, anyone ever got in this situation and has some tips on what to do ?


I had something similar happen to one of my Indys running 6.5.22 
recently, and I ended up running standalone fx from an installation CD 
to map out the corrupt sector and then reinstalling.  That wasn't too 
bad because I have all the necessary 6.5.x CDs as images on a server on 
the same network (so no tedious swapping of a dozen or so CDs) and I 
have a "selections" file for inst, with the things I need.


But since you have a bootable drive, you might be able to bring the 
system up with both drives installed, booting from the 6.5.16 drive, and 
running fsck over the (unmounted) 6.5.22 drive.  If that doesn't work, 
you could probably still create a selections file from the unbootable 
drive which you could use in the worst case of having to re-install.


--
Pete
Pete Turnbull

Re: DEC FPJ11-AA

[Pete Turnbull via cctalk]

On 02/07/2018 14:17, Bill Gunshannon via cctalk wrote:

On 07/02/2018 08:34 AM, Pete Turnbull via cctalk wrote:

Bill would want the -JD (2MB) version
(the -JE version is 4MB so too big).



Or a pair of the 1 meg ore did they go away before the 11/93 came out?


My oopsie; the MSV11-J is either 1MB or 2MB.  I was thinking of MSV11-Q 
(which is QBus only).


--
Pete
Pete Turnbull

Re: DEC FPJ11-AA

[Pete Turnbull via cctalk]

On 02/07/2018 03:38, Noel Chiappa via cctalk wrote:

 > From: Bill Gunshannon

 > Anybody have any PMI memory modules they might let go for less than my
 > first born male child?

The DEC PMI memories are the MSV11-J and (I think) the MSV11-R. The latter is
rare, but the -J's can be found.


Correct, but bear in mind that there are 4 versions of the MSV11-J; the 
-JB and -JC versions have different ASICs and don't support QBus CPUs. 
Specifically, they don't support block-mode transfers and don't work 
properly even as PMI memory except in an 11/84, while the -JE and JD 
versions support everything.  Bill would want the -JD (2MB) version (the 
-JE version is 4MB so too big).


--
Pete
Pete Turnbull

Re: DEC FPJ11-AA

[Pete Turnbull via cctalk]

On 01/07/2018 18:14, Bill Gunshannon via cctalk wrote:


Speaking of PMI  Anybody have any PMI memory modules they
might let go for less than my first born male child?  I have one
11/93 with 2 Meg and would love to bring it up to full memory.


If you really mean 11/93 (as opposed to, say, 11/83), it would normally 
only use its on-board memory.  It does work with PMI memory, but might 
it not be easier to just add the extra ICs on the CPU board?


--
Pete
Pete Turnbull

Re: Thicknet/10base5 Test Segment: The Cable is In!

[Pete Turnbull via cctalk]

On 29/06/2018 14:31, Paul Koning via cctalk wrote:


Yes, and the specified distance limit for RS232 is quite short, 50
feet or so.

People have used RS232 over longer distances, of course, and gotten
away with it.


The RS-232-C standard doesn't actually specify a maximum distance. 
Section 3.1  *recommends* short cables up to 50 feet or 15 meters (with 
speeds up to 20kbps) for RS-232 (and the later-dated Foreword suggests 
RS-449 beyond that) but says that longer is fine so long as the load 
capacitance excluding source and cable is less than 2500pF.  In 
practice, much depends on the baud rate and cable quality used.


--
Pete
Pete Turnbull

Re: ISO: DECtape controller

[Pete Turnbull via cctalk]

On 16 May 2018, at 08:37, Josh Dersch via cctalk  wrote:

>I was fortunate enough to acquire a TU56 this week, along with a TD8E 
>controller.  However, the TU56 lacks the G888 flip-chips necessary to work 
>with the TD8E; I know these parts are in short supply, but in the unlikely 
>event that anyone has (a) a set of 5 G888 boards, or (b) a TC01, TC08 or TC11 
>DECtape controller in any condition that they would be interested in 
>selling/trading for, please drop me a line. Thanks as always! Josh 

I have a similar problem. Has anyone re-engineered the G888?

Re: 8085 Dissasembly?

[Pete Turnbull via cctalk]

On 17/04/2018 14:25, Warner Losh via cctalk wrote:

On Tue, Apr 17, 2018 at 7:12 PM, Johnny Eriksson via cctalk <
cctalk@classiccmp.org> wrote:

Bill Gunshannon wrote:


Many of us think that the advent of the x86 architecture is what led to
masochism.



... or masochism led to the x86 architecture.



I think you are confused maybe. Wasn't it sadism?


Never attribute to malice that which is adequately explained by stupidity.

--
Pete
Pete Turnbull

Re: SGI Indy power supply: identify this diode?

[Pete Turnbull via cctalk]

On 26/03/2018 17:07, Pete Turnbull via cctalk wrote:

Except it's not a zener, or at least not anything like those [ones
Camiel and Bob suggested].  I took one out of another (working)
supply, and I can tell it has a forward voltage of 0.2V, so it's
presumably a Schottky diode of some sort.  I can also tell it's not a
low-voltage zener; the reverse breakdown voltage is more than 35V
(the highest my bench supply goes up to).


So I dug out my Avo 8, set to the 50µA range, hooked a matching diode 
from another Indy PSU up to a 300VDC supply via a couple of 1Mohm 
resistors and a 2Mohm pot as a voltage divider.  I found that as I wound 
the pot up from zero volts, the reverse leakage current rose abruptly 
from 2-3µA to a few tens of µA at about 59V across the diode, and the 
voltage across it dropped a little as I wound the pot up further.


So I think it's a Schottky rectifier diode, with a PIV rating probably 
between 50V and 60V.  Of course I have no idea what the current rating 
might be, and I can't think of a simple safe way to work that out.


Any comments?

--
Pete
Pete Turnbull

Re: Identifying an aluminum panel

[Pete Turnbull via cctalk]

On 31/03/2018 02:32, Kyle Owen via cctalk wrote:

I feel like I should know what this panel goes to...I found it in my garage
when cleaning up. Any ideas?

http://i.imgur.com/u4LMNqE.jpg


The shape, apparent size, and the bends and screw holes make it look 
remarkably like the bottom panel of my PDP-8/L, except that an 8/L 
doesn't weigh 80lb and the panel would be yellow passivated zinc-plated 
rather than silvery.


So I guess that's not much help ;-)

--
Pete
Pete Turnbull

Re: Digitising collections of microfiche - Re: Looking for opinions...

[Pete Turnbull via cctalk]

On 29/03/2018 05:26, Shaun Halstead via cctalk wrote:


Using the wrong filament orientation can cause some weird artifacts
to appear on scanned images, because of the high magnification. I
strongly suspect that an attempt using an LED source would face
similar (and possibly worse) issues.


Light source.  Due to lensing requirements, LED's are probably out, 
unless a way can be found to suitably diffuse or blend the source 
without losing significant light.  This requires a very strong light 
source.


Yet there are plenty of LED light sources used in photomicroscopy so I
don't believe it's that hard to do,which is why I suggested it.  I've 
seen it done with a high-brightness 5mm LED, but if a bit more "oomph" 
or a larger emitting area is required, there are inexpensive 1W and 3W 
LEDs that look like they'd work.  I'm no expert, but the biggest problem 
in photomicroscopy seems to be the spectrum, which isn't really an issue 
for monochrome microfiche.


--
Pete
Pete Turnbull

Re: Digitising collections of microfiche - Re: Looking for opinions...

[Pete Turnbull via cctalk]

On 29/03/2018 03:15, Zane Healy wrote:


More and more, I view my Classic Computer collection as a hinderance
to building a proper darkroom.  Oddly enough, the main purpose of my
PDP-11/44 these days is to hold a couple old enlargers that I don’t
use.


LOL!  I wish I still had my De Vere 5x4 enlarger, but I've nowhere to 
put such a thing.  Anyway, although I have access to some 5x4 Sinar 
equipment, the largest format I still have of my own is a couple of 
Mamiya 645s.


OT anecdote: Some years ago a colleague asked if I'd take her wedding 
photos.  I used to dislike doing that in the 70s and 80s so I wasn't 
keen on taking the hundreds of shots that seem to be the modern fashion. 
 She persisted, so I said I would if she bought me the 22 megapixel 
digital back for my Mamiya 645 Pro.  OK, she said, so I suggested she 
ought to check the price, after which she declined :-)


--
Pete
Pete Turnbull

Re: Digitising collections of microfiche - Re: Looking for opinions...

[Pete Turnbull via cctalk]

On 29/03/2018 00:19, Zane Healy via cctalk wrote:


I think Bellows would be the only sane way to approach this.  You
could do it with extension tubes, but they’re a pain.  Another thing
to consider is a light source.  You’re going to need a fair amount of
light, given the necessary extension to get the magnification.


I was going to suggest a Bowens Illumitran (which I have) but that sort 
of exercise wouldn't be kind to the flash tube.  LEDs would be my 
preferred solution; given the small area you might only need one bright 
white 5mm LED.


The Illumitran uses bellows, but for a lot of DEC fiche, the page size 
is constant so extension tubes might actually be better - they won't slip.



One of my favorite books, I think I’m up to 5 editions of it. :-)
You’d be hard pressed to find a photography book with more data in
it!


My favourite is L.P.Clerc "Photography" (six volumes), but second is
either M.J.Langford's 3-volume "Photography" set, mainly because I got 
it for college, or the "Ilford Photography Manual".


--
Pete
Pete Turnbull

Re: SGI Indy power supply: identify this diode?

[Pete Turnbull via cctalk]

On 26/03/2018 17:39, et...@757.org wrote:
I'm hoping I don't have to breadboard a 1kV supply and find a lot of 
multi-megohm resistors to try and estimate the breakdown voltage - and 
then guess at the forward current rating.


Is it possible to get the schematics?


If only!  That question has been asked many times on SGI forums like 
nekochan, for the Sony PSU (like this one) and also the Nidec.  No-one 
has ever claimed to have seen one, and the chances are Sony wouldn't 
ever have released them.


I have thought about tracing out the relevant area of the circuit, but 
it would take a while as the components are fairly densely packed, and 
I've got several other tasks on the agenda.


--
Pete
Pete Turnbull

Re: SGI Indy power supply: identify this diode?

[Pete Turnbull via cctalk]

On 26/03/2018 16:08, Camiel Vanderhoeven wrote:

4B would be a 2.2V zener; 4A would be a 2.0V zener, so that’s odd indeed...


That's the idea I had...

Except it's not a zener, or at least not anything like those.  I took 
one out of another (working) supply, and I can tell it has a forward 
voltage of 0.2V, so it's presumably a Schottky diode of some sort.  I 
can also tell it's not a low-voltage zener; the reverse breakdown 
voltage is more than 35V (the highest my bench supply goes up to).


I'm hoping I don't have to breadboard a 1kV supply and find a lot of 
multi-megohm resistors to try and estimate the breakdown voltage - and 
then guess at the forward current rating.



On 3/24/18, 9:47 PM, "cctech on behalf of Pete Turnbull via cctech" 
 wrote:

 After a recent power cut and a series of glitches as the power was
 restored, one of my Indys suffered a PSU failure.  It's a Sony APS-81
 171W unit, SGI P/N 060-0008-001.  I've found half a dozen damaged parts,
 and I've identified a 150R 1W metal film resistor (R135), two trannies
 (Q105, a 2SC4304 and Q106, a 2SC2785) and a couple of small diodes.  One
 of them (D116) appears to be a 6.2b2 (6.2V 1/2W) zener.
 
 The other one I'm not sure about.  On the PCB it's labelled D113, and

 it's adjacent to the 2SC2785.  It's very small, with a green band at the
 cathode end, and the legend "4B" in green - photos at
 https://www.flickr.com/photos/pnt103/albums/72157667056183978
 
 Oddly, another Sony PSU I looked at had a diode there that looked

 identical except it's marked "4A".
 
 I have an idea what it might be but if anyone actually knows what family

 or type/value this is, I'd be grateful for any insight.


--
Pete
Pete Turnbull

SGI Indy power supply: identify this diode?

[Pete Turnbull via cctalk]

After a recent power cut and a series of glitches as the power was
restored, one of my Indys suffered a PSU failure.  It's a Sony APS-81 
171W unit, SGI P/N 060-0008-001.  I've found half a dozen damaged parts, 
and I've identified a 150R 1W metal film resistor (R135), two trannies 
(Q105, a 2SC4304 and Q106, a 2SC2785) and a couple of small diodes.  One 
of them (D116) appears to be a 6.2b2 (6.2V 1/2W) zener.


The other one I'm not sure about.  On the PCB it's labelled D113, and
it's adjacent to the 2SC2785.  It's very small, with a green band at the
cathode end, and the legend "4B" in green - photos at 
https://www.flickr.com/photos/pnt103/albums/72157667056183978


Oddly, another Sony PSU I looked at had a diode there that looked
identical except it's marked "4A".

I have an idea what it might be but if anyone actually knows what family
or type/value this is, I'd be grateful for any insight.

--
Pete
Pete Turnbull

Re: PDP8/e programmers consoles

[Pete Turnbull via cctalk]

On 17/03/2018 00:28, Charles Dickman via cctalk wrote:

So the PDP8/e used the KC8-EA programmers console which has
incandescent indicator lamps and the PDP8/f used the KC8-FL
programmers console which has LED indicator lamps.


I have two 8/e machines, one of which has the original panel with 
incandescent lamps and one which is a slightly later panel (but the same 
type, just a later revision) which has been converted - I believe by DEC 
- to use LEDs.  I've experimented with different LEDs, and found that 
some yellow ones look quite convincing, but as I remember using PDP-8s 
with red LEDs back in the day, I've kept the original red ones.


--
Pete
Pete Turnbull

Re:

[Pete Turnbull via cctalk]

On 30/01/2018 15:17, Tapley, Mark via cctalk wrote:


Does Isopropyl alcohol (um, same as propan-2-ol?) at 60C have enough vapor 
pressure to be a flammability issue?


Yes.  The boiling point of IPA is a little over 80C, and the flash point 
of 70% - 80% IPA (which would be a common strength) is much lower than 
60C; depending on the concentration, it would be not much more than 20C. 
 It's similar to ethanol in that regard.


> Should it be done only under a fume hood, or something like that?

Maybe, certainly for even small quantities make sure there are no flames 
or sparks nearby.


--
Pete
Pete Turnbull

Re: DEC H960 stabiliser feet. Have some questions.

[Pete Turnbull via cctalk]

On 07/01/2018 07:57, Steve Malikoff via cctalk wrote:

I can't find anything suitable on MMC 
(https://www.mcmaster.com/#countersunk-head-machine-screws/=1b0p4yz

) so Chuck's probably right, machine them up. Maybe start from a long
 5/16" shank hex-head bolt and put the countersink and 1/4-20 thread
 on.


That should work.


Thanks for the drawing for the kickplate. I'm assuming the plate goes
on after the feet have been placed on the rack, and the #10 screws
hold it all together. I'm guessing the kickplate is 16 guage 
sheetmetal..?


Near enough, my micrometer says between 1.65mm and 1.70mm, the variation 
probably being due to the paint.  For our American listeners, that's 
16SWG (not AWG!).


--
Pete
Pete Turnbull

Re: DEC H960 stabiliser feet. Have some questions.

[Pete Turnbull via cctalk]

On 07/01/2018 01:44, Chuck Guzis via cctalk wrote:

On 01/06/2018 04:54 PM, Pete Turnbull via cctalk wrote:


No, as would be obvious to anyone looking carefully at the photo (or the
real thing!), it's 1/4" x 20 UNC.  I really must learn to think before
putting finger to keyboard.


If it's "quarter-twenty", that's a size shared by many refrigerators and
other heavy household appliances.  I think I even have a few of those
mushroom-headed screws salvaged from one.


Except the proper screws are countersink head, not mushroom, because 
mushroom heads would prevent the kickplate being fitted (and the shank 
is 5/16" - only the end is threaded 1/4-20).


--
Pete
Pete Turnbull

Re: DEC H960 stabiliser feet. Have some questions.

[Pete Turnbull via cctalk]

Sigh.  Third time lucky.

On 06/01/2018 16:11, Pete Turnbull via cctalk wrote:


Correction - it's 10-32.   I found one of the screws, photo at
http://www.dunnington.cx/DEC/H960/kickplate/IMG_1006.JPG


No, as would be obvious to anyone looking carefully at the photo (or the 
real thing!), it's 1/4" x 20 UNC.  I really must learn to think before 
putting finger to keyboard.


--
Pete
Pete Turnbull

Re: DEC H960 stabiliser feet. Have some questions.

[Pete Turnbull via cctalk]

On 06/01/2018 15:45, Pete Turnbull via cctalk wrote:

On 06/01/2018 12:04, Steve Malikoff via cctalk wrote:
Using the measurements provided by Vince I've rejigged the drawing a 
bit and it ought to be closer.


Looks good to me except...

I had thought the hole in the front corner of the H960 was for a front 
panel pivot, but it seems the foot does actually use it.


Yes, that's essential!  But unlike in your drawing, the large screw that 
holds the stabiliser foot into that hole is a large-head countersunk 
screw, not a pan-head screw, and only the very bottom part of it is 
threaded, 8-32 IIRC.


Correction - it's 10-32.   I found one of the screws, photo at
http://www.dunnington.cx/DEC/H960/kickplate/IMG_1006.JPG

The head diameter is 15.9mm (5/8")
It's a 45 degree countersink with a flattened underside
The shank diameter is 7.9mm (5/16") and 49mm long
The threaded portion is 15mm long x 10-32
The overall length is 66.7mm (2-5/8")

--
Pete
Pete Turnbull

Re: DEC H960 stabiliser feet. Have some questions.

[Pete Turnbull via cctalk]

On 06/01/2018 12:04, Steve Malikoff via cctalk wrote:

Using the measurements provided by Vince I've rejigged the drawing a bit and it 
ought to be closer.


Looks good to me except...


I had thought the hole in the front corner of the H960 was for a front panel 
pivot, but it seems the foot
does actually use it.


Yes, that's essential!  But unlike in your drawing, the large screw that 
holds the stabiliser foot into that hole is a large-head countersunk 
screw, not a pan-head screw, and only the very bottom part of it is 
threaded, 8-32 IIRC.  The main part is a plain shank to fit the holes 
for the front panel pivot and also the holes in the stabiliser; only the 
part protruding below the stabiliser is threaded.  It's fitted with a 
shakeproof ("star") washer along with the nut, under the stabiliser.  I 
took all the stabilisers off my racks because they're superfluous in my 
setup, and I can't remember where I put them, so I can't double-check.



I don't have the kickplate nor access to measuring one, so that probably 
changes it a bit too.


That I do have, so I took it off one of the racks and you'll find some 
(poor quality, from a phone that doesn't do close focus very well) 
pictures at


http://www.dunnington.cx/DEC/H960/kickplate/IMG_0999.JPG
http://www.dunnington.cx/DEC/H960/kickplate/IMG_1000.JPG
http://www.dunnington.cx/DEC/H960/kickplate/IMG_1001.JPG
http://www.dunnington.cx/DEC/H960/kickplate/IMG_1002.JPG
http://www.dunnington.cx/DEC/H960/kickplate/IMG_1003.JPG

and a hastily drawn sketch of the dimensions at
http://www.dunnington.cx/DEC/H960/kickplate/kickplate.pdf
(NB This is a sketch, not a technical drawing, and is only approximately 
to scale).


--
Pete
Pete Turnbull

Re: Old DEC PROM Images

[Pete Turnbull via cctalk]

On 02/12/2017 09:11, Mattis Lind via cctalk wrote:

2017-12-01 19:16 GMT+01:00 Bill Gunshannon via cctalk 

Re: PDP-8 chassis on eBay

[Pete Turnbull via cctalk]

On 07/11/2017 15:09, william degnan via cctalk wrote:

The seller in the past sold an 8i I believe, it's probably an 8i.
Bill

On Tue, Nov 7, 2017 at 10:00 AM, Dave via cctalk 
wrote:


Can you tell which PDP8 this goes with?  Would an 8/e panel fit?
Dave


It's an 8/e (of which I have two, and a nearby friend has three or four 
more, as well as a couple of 8/Ms) chassis.  It takes a big linear PSU 
and two 10-slot Omnibus backplanes.  The 8/F and 8/M (OEM version, 
usually with a very simple turnkey panel) are shorter, take only one 
10-slot Omnibus backplane, and have a completely different switch-mode PSU.


--
Pete
Pete Turnbull

Re: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM drives on a IBM PC]

[Pete Turnbull via cctalk]

On 03/10/2017 01:04, Tom Gardner via cctalk wrote:

Unfortunately there is no documentation to support Pete's recollection - if 
there is any I would like to see it.


Well, actually, there is, though not for quite as early as I had those 
conversations.  The company I was referring to was HCCS Associates, and 
although I can't find a copyright date for their original software, I 
can find pictures of the interfaces, clearly labelled "IDE", and one 
version of the software, called "IDE Manager".  It's version 2.1, dated 
February 1990.  They used mostly, but not exclusively, Connor drives, by 
the way.

http://chrisacorns.computinghistory.org.uk/Software.html#H
http://chrisacorns.computinghistory.org.uk/32bit_UpgradesH2Z/HCCS_IDE_A3000.html

Another I can find is another company who made an interface for a 
slightly later machine from the same family, and one version does carry 
a date, also 1990.

http://chrisacorns.computinghistory.org.uk/32bit_UpgradesH2Z/ICS_ideA.html

The Watford Electronics IDE interface (called WE-IDE) for the same 
series of machines was released about the same time.  The software is 
dated September 1989.  They used Western Digital drives, amongst others.

http://chrisacorns.computinghistory.org.uk/Software.html#W

So there's clear proof that at least three companies in the UK were 
using the term IDE before (or at least by) 1990.  I never heard it 
called anything else in that timeframe.



-Original Message-
From: Pete Turnbull [mailto:p...@dunnington.plus.com]



Nope.  I recall conversations with a small-scale developer in the UK who was 
creating addons and accessories for the company I worked for (Acorn
Computers) in 1987-1988, and he was touting IDE


--
Pete
Pete Turnbull

Re: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM drives on a IBM PC]

[Pete Turnbull via cctalk]

On 01/10/2017 20:46, Tom Gardner via cctalk wrote:

As best I can tell WD began publically using the term IDE for its drives sometime around 1990 


Nope.  I recall conversations with a small-scale developer in the UK who 
was creating addons and accessories for the company I worked for (Acorn 
Computers) in 1987-1988, and he was touting IDE as best improvement 
(because simpler and cheaper to interface) on ST506/ST412 interface 
drives for the hard drive upgrades he was about to market.  I recall 
having to ask what IDE stood for, at the time.  So it must have been in 
common use, at least amongst developers, by then.  By 1989 there were 
more people using "IDE" - by that name - than anything else in the 
markets I was involved in.


--
Pete
Pete Turnbull

Re: Tips For Soldering a Surface Mount PLCC Socket

[Pete Turnbull via cctalk]

On 10/09/2017 20:55, Rob Jarratt via cctalk wrote:

I want to replace a PLCC84 surface mounted chip and take the opportunity to
socket it.

I have looked at some YouTube videos to see how others have done this. I am
thinking that the best way is going to be to pre-solder the pads on the
socket, place the socket on the board and then heat the pads on the socket
from above with my finest tip.


Even with good flux, you'll find that difficult to get right, as the 
solder on the socket pins won't be perfectly even and it won't sit 
properly flat on the PCB pads.


You need decent solder paste, as sold in a small syringe, and the 
matching liquid flux. Be sparing with the paste and generous with the flux.


--
Pete
Pete Turnbull

Re: DEC ll/03 in 22 bit backplane

[Pete Turnbull via cctalk]

On 30/08/2017 17:02, Douglas Taylor via cctalk wrote:

On 8/30/2017 5:53 AM, Pete Turnbull via cctech wrote:

Hope this helps...


Yes, it does help.  There are 3 issues that I am trying to resolve:

1. Running in 32kb of memory.   If I use the 32kb MXV11 can I run RT11 
V5.3?


If it works in SIMH it should be just the same on real hardware - modulo 
any backplane bitness issues.


2. Bootstrap. I transferred the RT11 V5.3 to a DEC 535MB SCSI disk and 
was able to boot it using an Alphatronix SCSI controller, it is a Viking 
QDO rebadged.  When I say is was able to boot it, I 
connected it to a 11/53 CPU in a BA23 box just to test it out.


That has a J11 CPU, same as your 11/73, with the same registers.  So I'd 
be guided by others'  comments on booting the UC07.  You could of course 
program the MSCP bootstrap and whatever else you need for setup into a 
pair of EPROMs but that's perhaps not a good place to start.


3. 18 Bit addressing.  It appears that the H9270 backplane I have has 
been modified by DEC with wire wrap and soldered in connections.  I 
really, really don't want to undo any of that.  I may have to settle for 
just running an 11/23, 11/53 and 11/73 cpu in this box.


I doubt if it was done by DEC, unless some failed servoid did it as a 
favour for the previous owner when upgrading it for the 11/23.  It was a 
common user upgrade, though.


--
Pete
Pete Turnbull

Re: HP Draftmaster I, Power Supply repair

[Pete Turnbull via cctalk]

On 30/08/2017 11:44, Camiel Vanderhoeven via cctalk wrote:

I believe that is true for some countries, in other countries they did
increase the voltage. I know it happened in the Netherlands, because we
measured the voltages at our university¹s datacenter over that period.


We (I'm in the UK) measured ours at over 255V on more than one occasion :-(

--
Pete
Pete Turnbull

Re: DEC ll/03 in 22 bit backplane

[Pete Turnbull via cctalk]

On 30/08/2017 05:29, Douglas Taylor via cctalk wrote:

I'll send along a picture of the rear of the back plane.  I'm getting
 the impression I can't do what I want with the old cpu cards, M7270
and M7264.

I had really hoped to be able to put together a simple system to 
demonstrate the differences in processing power between the 11/2 cpu,

 the 11/23 and the 11/73.

They are all dual width cards and it would have been simple to swap
them out.  I think to do it I would need 2 boxes, one with a 16 bit
backplane and the other with a 22 bit backplane.


I don't see why you couldn't do what you want with the BA11-M and a 
little work, *providing* the Emulex UC07 controller works in an LSI-1103 
system - and the manual (on Bitsavers) suggests it should.  Section 
1.6.3 says "The UC07/08 is compatible with the Q-Bus used on all LSI-11 
... series computers."


First, you'd need to undo any backplane upgrade that made it 22-bit 
instead of 18-bit.  BTW, there's no such thing as a 16-bit backplane, 
only 18-bit and 22-bit.  BDAL17/18 are always bussed, to allow for the 
use of parity, even in 16-bit-CPU systems such as an 11/03.


The only reason you need to do this is that the KD11-H and KD11-F 
processors put other signals on those lines, which the Emulex (and other 
22-bit devices) won't like and will interfere with.


The soldering you mentioned is almost certainly the extra four bus lines 
for the upgrade.  It will be on both the B and D fingers of the 
backplane, because it's a serpentine backplane with Q-Bus on both sides. 
 Look for wired connections between BC1, BD1, BE1, BF1 and between DC1, 
DD1, DE1, DF1.  Check there no other extra connections; sometimes people 
added connections for other signals - for example I have a backplane 
with the SRUN signal on extra slots for diagnostics and faultfinding. 
Also check you don't have an H9270-Q, which is inherently 22-bit, 
instead of an H9270.  I've never seen one, but presumably they exist.


See http://www.dunnington.info/public/PDP-11/QBus_chassis for a little 
more information.


Next you'd need some sort of bootstrap.  What's in the custom EPROMs on 
you MXV11-AC might do.  Or might not, depending on whether it uses any 
11/23 (KDF-11) specific instructions or diagnostics, and includes an 
MSCP bootstrap.  The autoboot feature on the UC07 might do instead.  Or 
might not.  You'd have to experiment.


If you do keep the MXV11-AC, you've already got 32KB of memory that 
works with any of your 11/03, 11/23, or 11/73 processors, and you have 
two DLV11-compatible serial ports.  In fact the serial ports are 
virtually identical to half of a DLV11-J.  Since RT11 rarely has any use 
for more than two, you probably don't need any more.


If you keep the MXV11-AC and re-enable the memory, you only want another 
32KB, and maybe not even that.  I can't remember if RT11 5.3 will run in 
32KB; it probably will, and I'm sure it would if suitably SYSGENned.  I 
do remember RT11 5.6 either didn't or didn't unless it was seriously 
pared down.  Don't use anything older than 5.3 because there are bugs in 
the MSCP drivers that prevent it working with just about anything other 
than RQDX1/2 interfaces.


Or you could probably use the MSV11-P.  It works in 18-bit systems, and 
should still work in a 16-bit (CPU) system, but obviously you'd only be 
using the bottom 64KB.  If you want "period" memory to match the 11/03, 
you could find an MSV11-DC or -DD to use instead.  The -DC has 32KB to 
supplement your MXV11-AC; the -DD has 64KB.  The -EC and ED versions are 
the same boards but with parity circuitry added, which makes them less 
common and more expensive, but they'd also do what you want.


Hope this helps...

--
Pete
Pete Turnbull

Re: This Is Such An Exciting Listing!

[Pete Turnbull via cctalk]

On 19/08/2017 00:46, Adrian Graham via cctalk wrote:

It doesn’t beat a listing from 15 or so years ago from a mate of mine who 
advertised a polo mint (lifesavers to our US types) in a clear case as ‘mint in 
box (mint, in box)'


Who remembers the sale of the air guitar?

--
Pete
Pete Turnbull

Re: pdp-8/e restoration.

[Pete Turnbull via cctalk]

On 07/08/2017 18:37, Rod Smallwood via cctalk wrote:

So to-morrow connect up a terminal that will do 110 baud and try an echo 
test.


Next part is interesting. There should be a way to fake a reader / punch 
and feed in tape images.


There is.  Look on Kevin McQuiggin's site:
http://highgate.comm.sfu.ca/pdp8/

In the section called "Software", about 1/3 of the way down, look for 
send.c or better still new-send.c (I call it rsend, on my system).  You 
might also find rim.c and the BIN loader useful.


They're also on my webpage, with the corresponding manpages:
http://www.dunnington.info/public/PDP-8/

That's the easiest place to get the manpages for rim.c, send.c, rsend.c. 
Here's the gist (top parts of the manpages):


rim - create RIM-format file from ASCII addr/instr
  rim is a very simple converter.  It reads in a file containing two
  columns of ASCII digits; the first column is a list of addresses (in
  octal) and the second is a list of machine instructions (also octal).
  Output is a file suitable to feed to the RIM loader on a PDP-8.

send, rsend - send a file in RIM or BIN format to a PDP-8
  send and rsend are utilities to transmit a RIM format or BIN format
  file from a UNIX (or other) host to a PDP-8 over a serial line.  The
  PDP-8 should be running the RIM loader routine prior to starting
  either of these programs.
  Input should be a file in RIM format or BIN format.  Output goes to
  the host serial port, which should be connected via appropriate cable
  to the PDP-8.
  send is a simple version, with built-in serial port settings and a
  fixed delay between characters.  rsend is more sophisticated; it can
  be controlled by command-line options or environment variables, and
  can accept input on stdin.

On a Unix (or Linux etc) machine you can pipe the output from rim to 
rsend, and if you're using papertape images (of which there are load on 
the net), rsend can strip the headers for you.


--
Pete
Pete Turnbull

Re: DECstation 220 - Out of Ideas?

[Pete Turnbull via cctalk]

On 25/06/2017 11:46, Rob Jarratt via cctalk wrote:


I have done a bit more tracing of components and have come across a
possibly anomaly. The signal that won't go low enough goes to the
input (pin 2) of a 74LS125 buffer.


As soon as I saw "74LS125" I thought, "Oh, yes, another one".  That's a 
fairly early design tri-state buffer, and in my experience they're not 
very robust.  We used to replace lots of those, though admittedly I'm 
referring to the DIL version.  Worth checking it out.


If you can't desolder all the SMD pins, try this trick: for each side, 
thread a piece of enamelled copper wire under the chip near the pins. 
Tie or wrap one one to some nearby component and hold the other end in 
your hand.  Starting at the end with the wire you're holding, heat each 
pin with your soldering iron, and drag the wire under it, thereby 
breaking its contact with the board.


Failing that, apply a tiny amount of flux to the pins, and heat it up 
with a hot air gun, preferably a temperature-controlled one, and lift it 
off with forceps (or flip it over with a small screwdriver).


--
Pete
Pete Turnbull

Re: RL02 Cables

[Pete Turnbull via cctalk]

On 20/06/2017 09:06, Aaron Jackson via cctalk wrote:

I think I have seen this too, and was actually beginning to wonder if a
box with the clunky connector was the only "official" way of doing it. I
believe I read somewhere about bypassing the connector on the back of
the drive and going straight inside with a ribbon cable. Not sure how
this would be terminated though, or if it would have to be straight
through or not.


I've done this once and IIRC it's straight through.  But you need a 
terminator, because the drive just goes into FAULT condition if there's 
no terminator, or it's not connected to a controller.


--
Pete
Pete Turnbull

Re: sticky copies and laser prints

[Pete Turnbull via cctalk]

On 06/06/2017 23:58, David Griffith via cctalk wrote:


Often when I comb through old documentation, I find that the years, 
heat, and pressure appear to have remelted the toner such that pages get 
stuck together.  Is there a danger of that happening with modern toners?


Yes.  Toner composition hasn't changed much.  BTW, the worst culprit is 
the plasticiser in PVC ring binders.  All mine have at least one sheet 
of acetate (most OHP (viewgraph) transparency sheets work) in front of 
the first page, and behind the last page, which helps prevent the problem.


--
Pete
Pete Turnbull