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101090 discussions

Combined Retro Tech and Vintage Computer Fair

by gilcarrick＠gmail.com

The Arlington Museum of Information Technology (AMIT) is sponsoring the first annual Vintage Computer Fair Light - South to be held in conjunction with The 15th annual Antique Science & Retro-Tech Show And Swap Meet. The combined event will be held Saturday, March 14, 2009 at the Ramada Hotel, Irving, Texas, 4440 W. Airport Freeway. from 10:00 am to 4:00 pm. Admission is $5. AMIT Director Gil Carrick said that this combined event should attract many visitors who are interested in displaying their vintage computing artifacts or in buying, selling, swapping or just seeing these artifacts. Vintage Computer Fairs have been held in other parts of the country, but this will be the first one in the South. Since this is the first of these events in the region, it will not feature any speakers and will only last one day - hence the term "lite." Antique Science & Retro-Tech Show And Swap Meet organizer Skip Solberg said that for a decade and a half the event has been a favorite spot for fans of this antique gear to show, sell and swap their stuff. Visitors interested in displaying or selling should contact Skip Solberg at 817-467-0368 or email solberg2 at airmail.net for pricing and availability of table space. If you'd like more information about the Retro Tech Meet, or to talk with Skip Solberg, please call 817-467-0368, email solberg2 at airmail.net or see the web site at http://www.slideruleguy.com/tx-1q09.htm. If you'd like more information about the Vintage Computer Fair, or to talk with Gil Carrick, please call 817-994-9213, email amit at tx.rr.com or see the web site at http://amit-tx.org/. -- A. G. (Gil) Carrick, Director Arlington Museum of Information Technology 1012 Portofino Drive Arlington, TX 76012

17 years, 3 months

Powering up a 20-year old MicroVAX II

by ard＠p850ug1.demon.co.uk

> The harness I have is not the same as either of the two that someone sent me > pictures of. It is not a ribbon cable, it has discrete wires, of different > lengths, its part number is 70-20450-01, rev C1 and there is a date of 9th > Dec 1985 on it. The actual connectors though look like the connectors on the > bad ribbon cable harness, I think they are MTA-156. AFAIK this is a side issue. While the older pawer harness can overheat _in use_, it will not cause the PSU to fail at switch-on. In other words, if you have the older harness, you should reuild/replace it, but this is not the cause of your problem/ > > Some have suggested it blew because I had insufficient load. I had a TK50 > and an RD53 attached, would that no be sufficient. Furthermore I did not As I said earlier, I'd not use thos 2 devices as dummy loads, they are simply too valuale for that. Get soem 6V and 12V car bulbs... While I beleive there are SMPSUs that fail if turned on with no/insufficient load, I've yet to meet one. I've seen supplies that trip repeatedly if given no load. I've seen supplies (including ones from DEC) where some of the outputs give far too _low_ a voltage if the main output is not suffiiently loaded. But not one that fails. > actually switch the PSU on, just connected it to the mains, would the load > connected to the PSU matter when the PSU is not actually switched on? Hang on Are you saying the rocker switch on the front was not turned on? In which case most of the PSU electronis was not powered. About the only thing that could have failed in the way you descrie are the mains input filter capacitors. Have you opened up the PSU case yet? Can you see anything obviously burnet or exploded? If so, what? > > There was also a suggestion that the PSU would have needed switching > separately for 50Hz operation as well. The hardware manual I have for the > machine tells me how to switch between 110 and 240, but does not say > anything about switching it for frequency, so I suspect this was not an > issue here. It isn;t. There is no frequency adjsutment on the BA23 PSU. > > >From the various responses I think it would be unwise for me to attempt a > repair. Is there anyone on this list who is in the UK who would be willing > and able to fix this PSU, or who knows someone who might be? Where are you in the UK? -tony

17 years, 3 months

Zilog suicide

by dgriffi＠cs.csubak.edu

Since it seems like Zilog is intent on committing suicide by getting rid of its engineers, does anyone have any ideas on who will acquire the ruins when it's all over? -- David Griffith dgriffi at cs.csubak.edu A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?

17 years, 3 months

seeking barcode scanner

by dgriffi＠cs.csubak.edu

I was wondering if anyone here has an unloved USB laser barcode scanner. -- David Griffith dgriffi at cs.csubak.edu

17 years, 3 months

S-100 power supply voltage ranges

by Watzman＠neo.rr.com

8 volts and 16 volts is correct. Frankly, I would stay on LOW side (but not below 7.5 volts). MANY systems burn up boards because they are towards the high side (it was a huge issue for early SOL-20's). S-100 boards use linear regulators, and many of them pushed those WAY too hard, to the point that they got so hot they charred the board. Some notable candidates includes the Tarbell double density controller card, the IMSAI SIO2-2 card and a number of memory cards. At 9 volts, the linear regulator has to dissipate 4 volts x {whatever current}. A board like the Tarbell double density board has one regulator for the entire board, about 60 ICs including some big LSI chips (179x FDC & Intel 8257 DMA) and ONE linear regulator that gets ridiculously hot at even 8 volts. The difference between 8 volts and 9 volts is 25% and makes a HUGE difference. Barry Watzman ------------------------------ Message: 25 Date: Sat, 28 Feb 2009 10:03:10 -0500 From: "Andrew Lynch" <lynchaj at yahoo.com> Subject: S-100 power supply voltage ranges To: <cctalk at classiccmp.org> Message-ID: <6FB56B9FDD5B49A78CDD0BB4DD3B4BF5 at andrewdesktop> Content-Type: text/plain; charset="us-ascii" Hi! What are acceptable voltage supply ranges for an S-100 power supply? I am assuming 115VAC input. My intended application is a small home brew S-100 backplane. I have seen the S-100 voltage rails vary but I believe +15VDC, -15VDC, and +9VDC would be sufficient. Herb's S-100 page lists the voltages as +18VDC, -16VDC, and +8VDC but I have seen other voltages used. Thanks and have a nice day! Andrew Lynch

17 years, 3 months

1" paper tape buy ?

by csquared3＠tx.rr.com

On Thu, 26 Feb 2009 14:18:59 -0700 Mike Loewen wrote: > On Thu, 26 Feb 2009, Gordon JC Pearce wrote: > >> Didn't someone once work out that to store a single MP3 you'd need a >> stack of 80-column cards ten miles high? > > Assuming a 6MB MP3 file and 40 bytes per card: > > 6 * 1048576 = 6291456 bytes > / 40 bytes per card = 157286.4 (157285) cards > * .178mm card thickness = 27996.73 mm high > / 25.4mm per inch = 1102.233465 inches > / 12 = 91.85278871 (91.85) feet > > > Mike Loewen mloewen at cpumagic.scol.pa.us > Old Technology http://sturgeon.css.psu.edu/~mloewen/Oldtech/ Umm if you store binary ... that is 80 bytes per card .. 46 feet per file. Now how many dec tapes is that? Errr, ISTR that a standard IBM, etc. punched card was 0.0065" thick rather than the 0.007" implied by the 0.178mm, BICBW. Also, since there are 12 rows per column, the most efficient packing technique could store 120 bytes in the up to 960 "bits" (hole positions) in the card. Using those numbers, I came up with the following: 6,291,456 bytes / 120 = 52,428.8 cards (OK, 52,429) 52,429 * 0.0065 = 340.7885 inches or about 28.4 feet per file. What an improvement. ;) (Is anyone else bored today?) I also seem to recall that Univac or some other computer manufacturer actually used a 90 (?) column card for even better packing density. I'll leave that improved calculation to someone who actually remembers how many columns those cards were blessed with. Later, Charlie Carothers -- My email address is csquared3 at tx dot rr dot com

17 years, 3 months

compact pdp11 and front panel

by ajp166＠bellatlantic.net

Qbus -11s are poor candidates as they are hard to stall. That said you can display the dynamic address and data. This does meand latching the multiplexed address and data and providing led drivers for that. Also note as Chuck has said very little of the CPU state is brought to the bus so you cannot see 11/34 or 11/70 style info. To be able to write to memory or incrementially display a location is far harder as the CPU is continiously active and hard to stop and restart without some code. A switch flipping blinkin lights front pannel for an 11 is not simething I've missed and I"ve run 11/34s and 11/70s. In both those cases they were never used or needed. Allison > >Subject: Re: compact pdp11 and front panel > From: Dave McGuire <mcguire at neurotica.com> > Date: Mon, 02 Mar 2009 12:11:44 -0500 > To: "General Discussion: On-Topic Posts Only" <cctech at classiccmp.org> > Cc: cctalk at classiccmp.org > >On Mar 2, 2009, at 4:33 AM, David Griffith wrote: >> Does anyone know anything about shoehorning a front panel with lots >> of lights and switches onto a compact pdp11 (say, a /73 or /83)? > > I don't know anything about it specifically, but just from >thinking about it...I think the best you'd probably be able to do is >address and data LEDs, plus RUN, and maybe a few others...not much >more (i.e., no address spaces, processor states, etc) because the >signals aren't brought out to the pins on the J11 chip. > > But if that'd be enough, you could probably do it by using some >buffers to drive the LEDs, and doing DMA cycles onto the bus for the >switches. I'd probably take a whack at it if I had some time. > > -Dave > >-- >Dave McGuire >Port Charlotte, FL

17 years, 3 months

compact pdp11 and front panel

by dgriffi＠cs.csubak.edu

Does anyone know anything about shoehorning a front panel with lots of lights and switches onto a compact pdp11 (say, a /73 or /83)? -- David Griffith dgriffi at cs.csubak.edu A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?

17 years, 3 months

SGI 4D/220s

by legalize＠xmission.com

[Oops, hit send too quick] Just scored a couple SGI 4D/220s from a government auction site. Anyone have any familiarity with these? Anything I should look out for besides what's listed on various SGI web sites? (sgistuff, obsolyte, etc.) Crappy auction pics: <http://www.xmission.com/~legalize/vintage/images/4D-220-1.jpg> <http://www.xmission.com/~legalize/vintage/images/4D-220-2.jpg> -- "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download <http://www.xmission.com/~legalize/book/download/index.html> Legalize Adulthood! <http://blogs.xmission.com/legalize/>

17 years, 3 months

Emulex SCSI Controllers available...

by mcguire＠neurotica.com

On Thu, February 26, 2009 8:42 pm, Pete Turnbull wrote: >>> UC07's are QBUS cards which have a single SCSI port and support >> >> Uh, UC07s are UNIBUS, not QBUS. I've got a UC08, the dual-SCSI port >> version of that. > > No, they're definitely QBus, as is UC08. They're both quad-height > cards, at least the ones I've come across, but I believe there was a > later dual-height version with the same designation. I don't have one > but they're listed in lots of places and I know they work in microVaxen > as well as PDP-11s. UC17 and UC18 are Unibus, I believe. This is correct; the UC17/UC18 are Unibus. I've got a UC17 here. I've never seen a UC07, but docs say it is Qbus. -Dave -- Dave McGuire Port Charlotte, FL

17 years, 3 months

cctalk Digest, Vol 67, Issue 1

by mtapley＠swri.edu

At 8:46 AM -0600 3/1/09, Dan wrote: >0x105 here, damn you guys make me feel old, I'm 41 >and grew up with the old systems and move to unix later too... 0x8A, 46 years old. Sigh. Wasted years....at least I understand the scoring. -- - Mark 210-379-4635 ----------------------------------------------------------------------- Large Asteroids headed toward planets inhabited by beings that don't have technology adequate to stop them: Think of it as Evolution in Fast-Forward.

17 years, 3 months

FS: joystick

by charlesmorris800＠centurytel.net

I am pretty sure it's for an Apple II or Franklin clone. says "CH" as the manufacturer and has a DIP plug on the end of the cable. $8.00 shipped in the US. http://tinypic.com/view.php?pic=25ssvue&s=5 thanks Charles

17 years, 3 months

Antikythera fans

by evan＠snarc.net

>>> Incorrect I can see, but how can you be "unethical" with a gearbox? Marchant contends (with a bunch of evidence, not speculation) that Price made some important technical decisions that were easy and emotional, rather than professional and scientific. Price's "Gears from the Greeks" is still the most * popular * article about the device, because for a very long time it was the only article. But a large amount of new research in the past few years uses much more advanced technical imaging and includes analysis of forgotten pieces of the device to which Price never had access -- pieces that severely change the device's story.

17 years, 3 months

S-100 power supply voltage ranges

by Watzman＠neo.rr.com

Actually, the factory fix was a "bucking transformer", a whole second power transformer installed out of phase in series with the primary power transformer so that the voltages were subtractive. There is a factory ECN on this topic. But the bridge regulator solution was common among the user base (I myself have used it) as a lot simpler and cheaper, and almost as effective. ------------------------------ Message: 3 Date: Sat, 28 Feb 2009 11:07:56 -0600 From: Jim Battle <frustum at pacbell.net> Subject: Re: S-100 power supply voltage ranges To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> Message-ID: <49A96F6C.6060602 at pacbell.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Chuck Guzis wrote: > All of the S100 boards I've seen use simple linear regulators, so you > > need some headroom--but not too much. A lot of S100 7805s and LM323- > 5s were operated within an inch of their maximum current ratings (some > had bypass resistors installed) and generated a lot of heat. I > > wouldn't run the supply rails any higher than I had to. > > Cheers, > Chuck > > The Sol-20 had an app note about this problem. Apparently they shipped them for a while with transformers that were out of spec with the end result that the unregulated power ran high. The recommended fix was to take a power bridge, mount it to the case, and wire it in series with the positive voltage run in order to get a ~1.4V drop.

17 years, 3 months

Dumping MCM6832 PROMs

by aek＠bitsavers.org

> Please mail me, if you are interested in the data i was reading from the ROMs. > It is in Binary format. Sorry to post this here, but email to the address you used appears to be bouncing. I'm interested.

17 years, 3 months

S-100 power supply voltage ranges

by ajp166＠bellatlantic.net

> >Subject: S-100 power supply voltage ranges > From: "Andrew Lynch" <lynchaj at yahoo.com> > Date: Sat, 28 Feb 2009 10:03:10 -0500 > To: <cctalk at classiccmp.org> > >Hi! What are acceptable voltage supply ranges for an S-100 power supply? I >am assuming 115VAC input. My intended application is a small home brew >S-100 backplane. > >I have seen the S-100 voltage rails vary but I believe +15VDC, -15VDC, and >+9VDC would be sufficient. Herb's S-100 page lists the voltages as +18VDC, >-16VDC, and +8VDC but I have seen other voltages used. > >Thanks and have a nice day! > >Andrew Lynch The minimim voltages are +8, +15 and -15 or otherwise said at least 3V greater than the on card regulator. The maximum is generally +10, +18, -18v the caveat here is while most of the regulators used will accept up to 25-30V excessive voltages leads to overheating especially on the +8 buss where the highest current users are. Ideally well filterd voltages at the minimum on the +8V, +15V busses are desired and there were a few S100 boxes that did exactly that. Allison

17 years, 3 months

8088 vs. 80c88

by les＠hildenbrandt.com

> > >> I am assuming the problem relates to following a lxi sp instruction >> immediatly with a call instruction, I can see how pipelining >> instructions could cause this failure. I cant immagine how calling >> the address which happens to match the sp would be an issue. > > >As far as we could determine, it was precisely the issue. >> My thought was that most cp/m programs either left the sp alone, and used >> the stack provided by cp/m, or set up a local stack early on in the >> program. In either case this bug could be completly avoided. Am I wrong >> here? Is the bug related to calling the address which happens to be in >> the sp? > > >Again, yes. I am sorry I am so slow here. Which is the problem? The value or the sequence? >Probably not a bug, but definitely a factor in determining if I >should have bothered to use the V20/30 for emulation at all. >Certainly, I wondered if the lack of Z80 instruction set support >would have been an issue. It was--and I supplied a software emulator >for that. Fortunately, I also included an software 8080 emulator, so >even users of JRT Pascal weren't left hanging. The Z80 thing is an interesting point. Before I started running CP/M on a V20, I allways ran on a 8085. I would get annoyed when cp/m software required a z80, because it was not a z80 operating system. I later did build a few z80 systems, a laptop and a 20mhz sbc system, but all of the coding I did for them was 8080, except for using the 16 bit io address features of the z80. >To clarify my point, would you try to run CP/M on a Rabbit uC with >all of its "we're just like a Z80 except when we're not" instruction >set? I've never tried, as the compatibility issues are just too >severe. I assumed the rabbit was a z180, you learn something new every day. I have done a few designes with z180's, but I cant even rememer what language tools I used at this point. Les --------------------------

17 years, 3 months

Antikythera fans

by gstreet＠indy.net

Hi Vern and Randy, I'm also interested in the Antikythera project. I _think_ I ordered the book, "Decoding the Heavens," but I won't know until it actually arrives. Ordered it indirectly via Amazon.com, but my money was soon quickly and unceremoniously refunded. I think and hope I then found another copy via bookfinder.com. I recently received an email claiming that it has been sent. Making something like this must be pretty prohibitively expensive wouldn't it? Still, I am interested. Thanks, Robert Greenstreet Message: 1 Date: Sat, 28 Feb 2009 10:39:50 -0800 (PST) From: Vernon Wright <vern4wright at yahoo.com> Subject: Re: Antikythera fans To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Message-ID: <278829.9301.qm at web65503.mail.ac4.yahoo.com> Content-Type: text/plain; charset=us-ascii Hi Randy, I responded quite favorably to your proposal. I'm wondering whether you got any other people really interested in the Antikythera device, and whether you are going to go on with the project. It'll probably be a couple of months before my shop is workable again; moving and all that. But I am interested. Regards, Vern Wright --- On Sat, 2/21/09, Randy Dawson <rdawson16 at hotmail.com> wrote: > From: Randy Dawson <rdawson16 at hotmail.com> > Subject: Antikythera fans > To: "classic computers" <cctalk at classiccmp.org> > Date: Saturday, February 21, 2009, 7:30 PM > wondering if you guys love this as much as I do. > > I would like to make a user group/club for it if there is > enough interest > > For myself, I am fully equipped here with machine > capability and stage one is to make the model (2005) as > currently known. > > Stage 2 is heck make these in volume, its a marvelous thing > and may be profitable. > > You cannot find a better classic computer than this. > > Randy Dawson

17 years, 3 months

N8VEM JUHA SD interface

by Volker.Pohlers＠gmx.net

Hello Mr. Lynch, I found your N8VEM project on web. I'm interested in JUHA SD interface for my own computer (http://homecomputer-ddr.de.vu/z9001/z9001_sdcard.htm) It is possible to get contact to Mr. Juha for some special questions? Sincerely yours, Volker (I send this email once again, now with header) -- Mit freundlichen 8 Bit Volker Pohlers homecomputer-ddr.de.vu - Z9001, Z1013, LC80, ... - Computer Bild Tarifsieger! GMX FreeDSL - Telefonanschluss + DSL f?r nur 17,95 ?/mtl.!* http://dsl.gmx.de/?ac=OM.AD.PD003K11308T4569a

17 years, 3 months

UNIX for the VAXstation or AlphaStation

by slawmaster＠gmail.com

Hi all; I realize that this sorta overlaps with a previous thread or two, but I thought I'd start a new one rather than practice necromancy. So, I've got both a VAXstation 4000-60 and an AlphaStation 250 here and after playing with it for a bit I've decided I don't really care for VMS so much that I want it on both of them. I'd like to find an interesting, preferably AT&T-style UNIX to run on one of them, so I'm hoping some of you can help me figure out my options. So far, I know I can run: -NetBSD -Probably some DEC/HP UNIXes (Tru64 on the Alpha?). I'd really appreciate perspectives on these different systems, user/admin experience, etc. I'm not looking to accomplish anything in particular here, I just want something to play around with on my DEC hardware while I wait for the PDP-11 :) Thanks John Floren -- "I've tried programming Ruby on Rails, following TechCrunch in my RSS reader, and drinking absinthe. It doesn't work. I'm going back to C, Hunter S. Thompson, and cheap whiskey." -- Ted Dziuba

17 years, 3 months

Heat Failures

by ohh＠panix.com

Hey, all: I'm hoping for some info about older micros and heat failure. We have an archaic system at work which is going stupid on us, and we're looking at repair-or-replace options. Let's say you have a system which is locking up due to heat problems. I suspect we've all seen that from time to time. We're talking failures where you can cool things down and reboot and the system comes back and works again, not failures where things are visibly melting and/or burning. :) Is there a "typical" mechanism by which heat causes a system to go south? If you get a system which is knocked out by heat, does it make it more prone to being knocked out by heat in the future? In other words, do heat failures make a system physically more susceptible to more such failures - is the damage cumulative? Any relevant info appreciated. Thanks! -O.-

17 years, 3 months

Lame

by evan＠snarc.net

I saw the following ad on Yahoo's homepage just now: http://www.snarc.net/falsealarm.jpg But as you can guess by the file name that I gave to the screen capture, it turned out to be lame -- just an advertisement for Yahoo Mail. Oh well.

17 years, 3 months

Whatever happened to MENTEC and the PDP-11?

by RodSmallwood＠mail.ediconsulting.co.uk

The last I heard of them was a takeover by Calyx. in 2006 I can't see any reference to PDP-11 on the Calyx Website. So what happened ? Rod (Renovates Old Dec)

17 years, 3 months

1" paper tape buy ?

by aek＠bitsavers.org

Fanfold would be of more interest than rolls. You can still buy rolls. There hasn't been a source for fanfold in a while. Western Numerical Controls had some interest in brokering with the paper company for fanfold if the quantity was high enough.

17 years, 3 months

Another classic-computer 'test'

by charlesmorris800＠centurytel.net

On Sun, 1 Mar 2009 18:56:56 -0600 (CST), you wrote: >This one did the rounds of a system I was on aout 20 years ago. Some of >the questions are certainly classic-cmputer related... > >Enjoy.. I scored 000115 octal. Don't feel like a "Sage" though :) -Charles

17 years, 3 months

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