VAXstation 4000/90

Send cctalk mailing list submissions to cctalk at classiccmp.org To subscribe or unsubscribe via the World Wide Web, visit http://www.classiccmp.org/mailman/listinfo/cctalk or, via email, send a message with subject or body 'help' to cctalk-request at classiccmp.org You can reach the person managing the list at cctalk-owner at classiccmp.org When replying, please edit your Subject line so it is more specific than "Re: Contents of cctalk digest..." 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: 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? 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: 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. ------------------------------ 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 Agreed [...] 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. 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. 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 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 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---|/ 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. 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. 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. 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. 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. 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. 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 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 ***************************************