New subject: Speaking of VAXstation 4000s...

27 Jul 2013

Hi, anybody out there playing with Vax's? Trying to work out if I have connect the
terminal correctly or if the logic board is dead. I posted on openvmshobbyist.com, but
that forum seems pretty sleepy. Is there any other forum for VMS thats active?

Regards,

Daniel.

Sent from my iPad

On 28/07/2013, at 1:00 AM, cctalk-request at classiccmp.org wrote:

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 Today's Topics:

   1. Re: LCD rot? (Eric Smith)
   2. Re: LCD rot? (David Cooper)
   3. Aug. 3-4-- HUGE lot of vintage micros f/s @ MARCH event in
      central NJ (Evan Koblentz)
   4. Available N8VEM PCBs on Vintage-Computer Marketplace
      (Andrew Lynch)
   5. Paging Glen Slick (Alexandre Souza)
   6. Re: LCD rot? (Chris Pye)
   7. Re: HP 9830A always turns on with blank display (Tony Duell)
   8. Re: Help identifying component(s) (Tony Duell)
   9. Re: HP 9830A always turns on with blank display (Tony Duell)
  10. Re: LCD rot? (Tony Duell)

 ----------------------------------------------------------------------

 Message: 1
 Date: Fri, 26 Jul 2013 10:32:52 -0600
 From: Eric Smith <spacewar at gmail.com>
 To: "General Discussion: On-Topic and Off-Topic Posts"
    <cctalk at classiccmp.org>
 Subject: Re: LCD rot?
 Message-ID:
    <CAFrGgTSj7sKF3yo-Mxqns=CFNARan5f_EuzFZCpC=q9QsvrRNA at mail.gmail.com>
 Content-Type: text/plain; charset=ISO-8859-1

 On Fri, Jul 26, 2013 at 9:56 AM, Geoffrey Oltmans <oltmansg at gmail.com> wrote:
  Heat might do it I suppose. I wonder if you could
"wake" them back up by
 forcing each pixel full on/full off over and over?  
 If there's a black line consisting of a full line or lines of pixels,
 that's most likely caused by either a fault in the driver for that
 line, or a failure of the electrical connection. Cycling the pixels
 won't help with that.

 There's a lesser chance of dead lines being caused by having a DC bias
 on that line for an extended period, which shouldn't happen except in
 a failure of the LCD controller. Cycling the pixels could help with
 that, but if the controller failed to cause it, it's unlikely that the
 controller has started working correctly again. Since this kind of
 failure only occurs when the LCD is powered up with the controller not
 working for an extended period of time, it's not going to result from
 having the LCD being stored unpowered for an extended time.

 The black blob problem, which usually eventually reaches the all-black
 case, is caused by a chemical change (oxidation?) of the liquid
 crystal material, and I don't think there's anything you can do
 electrically that's going to fix or even reduce the problem.  AFAICT
 that's caused by the seal failing, which can be caused by temperature
 extremes, but sometimes just happens as a result of aging.

 It can also be caused by mechanical pressure between the glass layers,
 but leaving it sit for a few years, even with wide temperature swings,
 shouldn't cause it in that manner.

 ------------------------------

 Message: 2
 Date: Fri, 26 Jul 2013 10:24:46 -0700
 From: "David Cooper" <trs80 at marmotking.com>
 To: "General Discussion: On-Topic Posts Only" <cctech at
classiccmp.org>,
    "General Discussion: On-Topic and Off-Topic Posts"
    <cctalk at classiccmp.org>
 Subject: Re: LCD rot?
 Message-ID: <14085220AD444885BF8F13AF1B3BA985 at planetx>
 Content-Type: text/plain; format=flowed; charset="iso-8859-1";
    reply-type=original

 I've seen it happen on all sorts of LCD displays no matter how they were 
 stored.  I think LCDs must just not age well.

 -----Original Message----- 
 From: dwight elvey
 Sent: Friday, July 26, 2013 6:19 AM
 To: General Discussion: On-Topic and Off-Topic Posts
 Subject: RE: LCD rot?

  From: pye at mactec.com.au
 Subject: LCD rot?
 Date: Fri, 26 Jul 2013 23:01:03 +1000
 To: cctalk at classiccmp.org

 I have just pulled a heap of old Apple PowerBooks and Newtons out of 
 storage, and have discovered that quite a few of the LCDs that were 
 perfect last time I looked at them (some probably not for seven years ago 
 now) have deteriorated to the point that they are no longer usable. 
 Problems vary from big black splotches on mono screens, to colour screens 
 with almost the entire display from the centre out showing only the 
 backlight.

 What are the causes for these kind of problems? Heat? Humidity?

 They have been stored for the last six or seven years in a cool dry 
 environment, but did spend one summer in a storage facility that could 
 have reached 40 deg c at times.

 Chris  The seal around the edge of the screen has failed.It may be the high heat 
 that does it??Dwight 

 ------------------------------

 Message: 3
 Date: Fri, 26 Jul 2013 16:13:02 -0400
 From: Evan Koblentz <evan at snarc.net>
 To: General Discussion: On-Topic and Off-Topic Posts
    <cctalk at classiccmp.org>
 Subject: Aug. 3-4-- HUGE lot of vintage micros f/s @ MARCH event in
    central NJ
 Message-ID: <51F2D84E.6040601 at snarc.net>
 Content-Type: text/plain; charset=ISO-8859-1; format=flowed

 Hi all. Remember this thread: 

http://www.vintage-computer.com/vcforum/showthread.php?37642-NJ-USA-Large-l…

 .....? Now it's time for we in MARCH to sell everything on the owner's 
 behalf.

 Rules are what you'd expect: nothing's being tested; nothing's being 
 shipped; cash only; no parting out; no "dibs"; etc. .... you've got to 
 BE THERE or be square.

 The following list is around 90% accurate. I might have mis-counted, for 
 example, where there are more than one of the same machine. Also, the 
 owner said there's a few other random items that will be available. And 
 last but not least, we in MARCH might grab one or two specific things 
 for the club collection; for example we might want one or two of the 
 Franklins.

 Keep in mind, the Aug. 3-4 event is NOT the VCF East -- that's not until 
 next April -- this event is primarily a vintage computer repair weekend. 
 Entry is $10.

 Without further ado, here's the rough list:

     Amstrad PPC640

     Apple II+ (x2)
     Apple IIc (several...)
     Apple IIe (x4)
     Apple IIgs (x4)
     Apple Lisa II (possibly XL; not sure)
     Mac Classic
     Mac SE
     Mac 512
     Mac Plus 1MB
     Mac IIcx
     Mac IIci (x4)
     Mac II
     Mac II Plus
     Mac Powerbook 170
     Mac LC
     Mac LC3
     Mac Quadra 605
     Mac Quadra 950
     Mac Quadra 800
     Mac Quadra 700
     Mac Quadra 800
     Mac Quadra 700
     Mac Portable
     Disk II (x4)
     misc. Apple kb+drives

     AT&T Unix PC

     C-64
     VIC-20 (x2)

     Compaq 286
     Compaq 386 in nice case
     Compaq Portable 3
     Compaq SLT 286
     Compaq portable 286
     Compaq portable 386
     Compaq portable 486C (x2)

     DEC Rainbow
     DEC Rainbow 100

     Epson HX-20

     Franklin ACE 500 (x2)
     Franklin ACE 1000
     Franklin ACE 1200
     Franklin ACE 2100

     box of Model M keyboards
     IBM 5155
     IBM 5140 (x3) -- one has a nice case
     IBM Power Station 340
     IBM Power Server 32xx
     IBM 8573/121 portable with case (x2)

     Osborne

     "random box of laptops"

     TRS-80 Model 1
     Tandy 4D
     Tandy 4P
     Tandy CoCo 3
     Tandy Model 2
     Tandy 8MB HD (x2)
     Tandy 6000HD (x2)
     Tandy 12
     Tandy CoCo
     Tandy Model 100
     Tandy Model 3
     Tandy CoCo2 (boxed) (x2)

     Kaypro II (x2)
     Kaypro 4
     Kaypro 2000

     Spark Server 1000
     Spark storage array
     Spark Voyager

     TI Professional Computer
     TI Silent 700

     Toshiba T1600
     Toshiba 3200 SCX
     Toshiba 4700CS

     Zorba luggable

 ------------------------------

 Message: 4
 Date: Fri, 26 Jul 2013 16:44:10 -0400
 From: "Andrew Lynch" <LYNCHAJ at YAHOO.COM>
 To: <cctalk at classiccmp.org>
 Subject: Available N8VEM PCBs on Vintage-Computer Marketplace
 Message-ID: &lt;009c01ce8a40$e1ed04f0$a5c70ed0$(a)YAHOO.COM&gt;
 Content-Type: text/plain;    charset="us-ascii"

 Hi

 I am selling multiple vintage computer related items including N8VEM home
 brew computer PCBs and parts on Vintage Computers and Gaming Marketplace.

 http://marketplace.vintage-computer.com/other_items.php?limit=100&owner…
 00048&item_type=all

 Please check out what's for sale and if anything interests you please
 contact me.

 Thanks and have a nice day!

 Andrew Lynch

 ------------------------------

 Message: 5
 Date: Fri, 26 Jul 2013 17:49:06 -0300
 From: "Alexandre Souza" <alexandre.tabajara at gmail.com>
 To: "General Discussion: On-Topic and Off-Topic Posts"
    <cctalk at classiccmp.org>
 Subject: Paging Glen Slick
 Message-ID: <F22BDC533F2644B6BEBE0B70B0788066 at tababook>
 Content-Type: text/plain; format=flowed; charset="iso-8859-1";
    reply-type=original

    Glen, I've sent you some private messages and got no answer, check your 
 spam folder! :o)

 ---
 Enviado do meu Motorola PT550
 Meu site: http://www.tabalabs.com.br 

 ------------------------------

 Message: 6
 Date: Sat, 27 Jul 2013 08:38:20 +1000
 From: Chris Pye <pye at mactec.com.au>
 To: "General Discussion: On-Topic and Off-Topic Posts"
    <cctalk at classiccmp.org>
 Subject: Re: LCD rot?
 Message-ID: <C961B4F6-C71F-4896-B200-1E16B9DF74A3 at mactec.com.au>
 Content-Type: text/plain; charset=iso-8859-1

 On 27/07/2013, at 2:32 AM, Eric Smith <spacewar at gmail.com> wrote:

  The black blob problem, which usually eventually
reaches the all-black
 case, is caused by a chemical change (oxidation?) of the liquid
 crystal material, and I don't think there's anything you can do
 electrically that's going to fix or even reduce the problem.  AFAICT
 that's caused by the seal failing, which can be caused by temperature
 extremes, but sometimes just happens as a result of aging.  
 I wonder if it is possible to reseal or place an extra seal on existing old (but still
good) displays to preserve them a bit longer.
  From my relatively small sample it seems that age
alone does't have much bearing, as out of eight Powerbooks the two older PB100 are not
affected (but they do have other problems).  

 ------------------------------

 Message: 7
 Date: Fri, 26 Jul 2013 22:47:32 +0100 (BST)
 From: ard at p850ug1.demon.co.uk (Tony Duell)
 To: cctalk at classiccmp.org
 Subject: Re: HP 9830A always turns on with blank display
 Message-ID: <m1V2prO-000J4ZC at p850ug1>
 Content-Type: text/plain

  The original circuit has a voltage divider for
the LDR formed with  
 the 18.2K resistor in the lower half and the LDR to +5V, feeding the  
 negative input of the 741, with the positive input fixed at 2.5V. The  
 result is the 741 (comparator) will trip when the LDR resistance  
 passes through 18.2KOhms.  
 Agreed

 [...]

  In your simulation, you used resistances for the
LDR of 74K dark and    
 I fial to see why you need to 'simulate' this circuit. The actual 
 comparator circuit, whether the origianl HP one iwth no feedback or the 
 intended modification is simple enopug hthat you can understand it in 
 your head.

 The dificult part is the sensor itself. Yes, you can measure the ligth 
 and dark resistances (and if they really are 74K and 4K then it should 
 work with an unmodified comparator circuit). But I don;t think you cna 
 simulatre the sensor more than that. There are too many unknowns.

  4K illuminated. That should have worked just fine
with the original  
 HP circuit, although it wouldn't work with the way you have actually  
 modded the board.

  I wrote it because it's a working (tested)
solution for an actual  
 problem.
 AND you can't just replace the CDSe type with a normal off the  
 shelf LDR
 that doesn't work, I tried..

 So be careful before just shouting something without testing it!  
 I'm not shouting, I am being careful - far more than you, and I have  
 repaired and done a fair degree of experimentation with these sensors  
 (in one instance replacing the lamp/LDR pair with an IR LED/ 
 phototransistor pair, and it didn't require any changes to the  
 comparator circuit).  
 Where are youre results/descriptions of this? Rik has desciribed what he 
 did, you have (quite probably correctly) found errors in it. But I don't 
 see your work published anywhere.

  I haven't counted how many items I have
reverse engineered, but it's  
 many dozens, over a hundred I expect depending on what level of    
 Is that all :-)?

 -tony

 ------------------------------

 Message: 8
 Date: Fri, 26 Jul 2013 23:03:08 +0100 (BST)
 From: ard at p850ug1.demon.co.uk (Tony Duell)
 To: cctalk at classiccmp.org
 Subject: Re: Help identifying component(s)
 Message-ID: <m1V2q6T-000J4dC at p850ug1>
 Content-Type: text/plain

  Those are the little "tin cans" that
IBM used, back in the early to mid 
 '70s, to enclose (encapsualte) their "medium scale integration" -- an 
 earlier generation, before the "LSI" (Large Scale Integration" chips 
 took over pretty much everything.

 These were used in virtually all IBM products of that day, from 
 mainfames, to minicomputers, to control units, and even inside other 
 intelligent devices, like the disk drives and printers, etc., for the 
 "logic" on-board ...  
 As an aside, IIRC the sense amplifier circuit in the original PC and 
 PC/XT keybaord used one of those metal-can ICs. 

 -tony

 ------------------------------

 Message: 9
 Date: Fri, 26 Jul 2013 23:21:53 +0100 (BST)
 From: ard at p850ug1.demon.co.uk (Tony Duell)
 To: cctalk at classiccmp.org
 Subject: Re: HP 9830A always turns on with blank display
 Message-ID: <m1V2qOe-000J4eC at p850ug1>
 Content-Type: text/plain

 > Secondly, IC pin numbers. Every IC has all
the connecitons  
> unambiguously
> described. If the pins all have unique names (like a RAM, or a  
> counter or
> a '154 decodoe) then I simply use those names or something obviously
> equivalent to them That is why tyou see things like signal BRA(2)  
> going
> to a pin on an 11/03 RAM labeleld A0. BRA(2) is 'Buffered RAM Address'
> bit 2. The 'bit 2' meanming it comes from address line 2 of the  
> processor
> eventially. A0 is the pin on the RAM that Intel called A0 in the  
> databook.
> 
> Nwo, for simpler TTL ICs, I have a convention. For things like AOI  
> gates
> I put the pins in alphabetical order from the TTL databook going  
> dwon the
> page. And for simple gates I draw them so that the 'upper' pin on the
> schemtic is towards the pin 1 end of the IC. So that, for example
> 
> 
> ---------|\
>         | >o---------
> ---------|/
>        U5c
>        '00
> 
> 
> Means
> 
>      10
> ---------|\   8
>        | >o---------
> ---------|/
>       9   U5c
>           '00
> 
> THis may not be obviouus, but all you had to do was ask me...  
 If forgot to add that the only non-obvious oen is section 'a' of a triple 
 3-input gat like the '10 or '27. The convention then is 

 1----|\
 2----| >0--- 12
 13---|/

  While one may want to communicate with an author
about more subtle  
 aspects of their work, this is such a basic thing I see no need for  
 asking, and waiting, for an answer about it. I can't say it would  
 even occur to me to ask, as if you have a convention about it, it    
 I have sene this convention used so many times that it never occured to 
 me to describe it. 

 In any case... The ouptus of all ICs are unambiguous. I don't think there 
 are any ICs in the HP9830 that have 2 identical output pins you could 
 confuse. In which case you could simply trace the few signal (often just 
 2) at the input of the gate back ot the outputs that drive them and 'buzz 
 them out' with an ohmmeter. It would take less time to do that for the IC 
 you are interested in than to post this message.

  could simply be noted at the beginning or end of
the work, along with  
 such things as source material identification, dates, table of  
 contents, etc.
 As a matter of preference, when working on something, I don't want to  
 have to go from the schematic, then to a pinout to interpret what pin  
 is being ref'd, and then to the device.  
 And I have the opposite preference I am afraid. I find pin numbers on 
 scheamtisc to be irritating. In most cases I know the common TTL pinouts 
 anyway. For anything else I don't mind having the data book open.

 Here are some disadvantages to hand-drawing, aside from basic clarity:
   1. The low density means the schematic is spread across more pages.  
 There is no inherrent reason why a hand drawn scheamtic has a lower 
 component density than a CAD one.

 The limitation on the number of compoentns o na bit of ppaer is  
 obviosuly due to the size of that paper. The limitation for a CAD system 
 is the size of the 'virtual paper'.

 And I find 'large' CAD diagrams to be a right pain. If you want a printed 
 copy, you either end up with a much reduced copy which is close to 
 unreadable, or a number of sheets that have to be lined up and stuck 
 together. I much preer diagrams desigend to be printed or drawn on A4 sheets.

    2. The difficulty of modifying and manipulating
a hand-drawing,  
 along with the low density,
      results in more symbolic connections. Symbolic connections,  
 while of course useful,
      are disadvantageous in that it is not readily clear where all  
 the uses of a signal are.  
 I think like you imply here I actually prefer symbolic names provided 
 they are meaningful (I ahve seen commerical multi-page diagrams where the 
 signals are just A...Z, AA,AB...AZ, etc) There are a few i nthe HP9830 
 diagrams where I will admit not to pickign the most suitable name. 
 'KeyDn/' is the obvious one, it's actualyl a general interrupt input to 
 the CPU. It goet that name becuase the first machien I looekd at was the 
 hP9810, and the only thing it's used for there is the keyboard. 

 Yes, a CAD system would have made it easy to change this. But the other 
 disadvantages mean I did not use one.

    3. (2) is compounded in that the drawings are
unsearchable.
      With a computer-based drawing, if one wants to find every  
 reference
      to some signal/symbol, one just walks through it with a search.  
 As an aside, I have never seen a commerical service manaul (on CD-ROM or 
 whatever) where yuo can search for signal neames on the schematics. 

    4. I don't expect OCR to be a remedy to
(3).

 You have your preferences and conventions, I have mine, some may  
 prefer yours, some may prefer mine.  
 I think that;'s right. I took a look at your AL1000 schematics (BTW there 
 are a couple of broekn links there). In the form you have presented them 
 they are very useful for understnading how the machine works, I think, 
 but not so useful for actually repairing one. Wpoorkign out what is on 
 each board, what components comprise each gate and flip-flop (and yes, I 
 ahve read your conventions, etc) is too much to have to deal with if I 
 had the machine in bits in front of me.

  This wasn't really about your schematic, it
was whether it is  
 acceptable for anyone else to RE something Tony already has.  
 Yo uare reading far too much into this. 

 I will just point out that _you_ raised the issue of my schematics. I 
 did not mention them at first.

 -tony

 ------------------------------

 Message: 10
 Date: Fri, 26 Jul 2013 23:33:07 +0100 (BST)
 From: ard at p850ug1.demon.co.uk (Tony Duell)
 To: cctalk at classiccmp.org
 Subject: Re: LCD rot?
 Message-ID: <m1V2qZV-000J4gC at p850ug1>
 Content-Type: text/plain

 I have just pulled a heap of old Apple PowerBooks and Newtons out of 
 storage, and have discovered that quite a few of the LCDs that were 
 perfect last time I looked at them (some probably not for seven years 
 ago now) have deteriorated to the point that they are no longer usable. 
 Problems vary from big black splotches on mono screens, to colour 
 screens with almost the entire display from the centre out showing only 
 the backlight.  
 For monochrome LCDs, a black splodge genrally means the liquid crystal 
 material has leakced out. Rememebr that there are corssed poalraising 
 filters o nthe sides of hte display and that the unenrgized state of the 
 liquid crystal is to rotate the polarisation of light by 90 degrees. So 
 that an unergized dispaly transmitls like (looks 'light') but if the 
 liquid crystal material leaks out, you are essentially lookuing trhoug 
 corssed polarising filters with nothign to rotate the plane of 
 polarisation, so it looks black.

 As yo waht caues it, damage to the seals between the 2 layers of glass. I 
 susepct heat or mechanical shock is a common cause of this damage.

 -tony

 End of cctalk Digest, Vol 119, Issue 36
 *************************************** 

VAXstation 4000/90