test-drb February 2007

test-drb@ccmp.vtda.org

208 participants
390 discussions

Tektronix terminals [was: Re: Re: Humpty Dumpty]

by blstuart＠bellsouth.net

Rick Bensene wrote: > The coolest Tektronix terminal, if you ask me, was the original Tek > 4002. > ... > There also was a 'write through' mode, > again, not sure if it was a hack, or part of the production terminals, > that would (within the limitations of the RS-232 port) could do simple > dynamic (non-stored) vector graphics. Don't know about the 4002, but I'm pretty sure it was standard on the 4014. We had one in college and I wrote a little thing that drew a wireframe pyramid in writethrough mode. You gave it a file of x, y, z rotations and it drew the animated pyramid. We were running it on a VAX 11/780 running VMS. Of course, when someone else got the CPU, the screen blanked. (If you didn't rewrite the lines fast enough, they went away.) So this friend of mine who was employed by the computing center (as was I) as an operator got this "brilliant" idea. We had privileges to create queues. So he created one with real-time priority so that it wouldn't blank out. It worked in that the animation was quite smooth. But >from the perspective of everyone else on the system, it had locked solid. We did finally get logged in and killed the queue, but as I recall it took about 30 to 45 minutes. BLS

18 years, 2 months

Copying a Mac Disk with a Single Drive

by mtapley＠swri.edu

At 11:56 -0600 2/8/07, Scott wrote: >but the default >gives you lots of wrist exercise even on a 4MB Mac SE/800k. My favorite sniglet for this is, "MacElbow". --

18 years, 2 months

Anyone have real tech info on HP54201D (Digital Storage Scope)

by dave06a＠dunfield.com

Sorry - I know this is a bit OT, but I don't know many places to ask... Does anyone here have technical information or experience with the HP54201D Digitizing Storage Oscilloscope. I'm specifically looking for information/help with the analog triggering circuits. I've obtained the HP "service manual" for this scope, and it is absolutely useless, no schematics, not technical descriptions... Basically, it says "Plug the scope into your HP scope tester, press GO and replace any boards which are listed as FAILED". I've had this machine for a few months. It's always had problems with the analog triggering. When I first got it, channel-1 would not trigger at all, but channel-2 and external triggering worked most of the time. Channel-1 would fail the trigger Hysteresis & Level calibration, Channel-2 would usually pass. I've been using it with Channel-2 triggering, however within the past week, I've noticed that it triggers continuously after power on (Doesn't matter what trigger level etc. you program), but after a few minutes it would settle down and work as before. Thinking it might be a calibration issue, I re-ran self-calibration, and surprisingly Channel-1 passed, after which I could use both channels with full triggering, however both of them exhibited continuous triggering after power-on, and the time taken to settle down has been increasing. This morning, it's been on for over three hours and it's still triggering continously, even with no signal inputs (leads disconnected). Triggering calibrations fail consistantly for both channels. So I think it has finally gone bye-bye. When it works, this scope is awesome - I would really like to get it working again - any information/help would be greatly apprecaited. Regards,. Dave -- dave06a (at) Dave Dunfield dunfield (dot) Firmware development services & tools: www.dunfield.com com Collector of vintage computing equipment: http://www.classiccmp.org/dunfield/index.html

18 years, 2 months

Preservation of Correspondence - And Media

by Billy.Pettit＠wdc.com

Chuck Guzis wrote: While I'd like to believe that DVD-R media has the same permanence, my problems with DVD players successfully reading movies and such makes me suspicious. It could be that DVD is just "pushing" the technology a bit. Storage for CD-Rs in stlil in styrene jewel cases. We'll occasionally use PVC cases as mailers (they survive the rigors of the USPS better), but we advise customers to use traditional styrene cases for storage. From what I've read on the archivists' list, some PVC material has been found to outgas chlorine. Cheers, Chuck -------------------------------------------------- I never quite know how to take all the disk bashing that seems to come up periodically on this list. One point that seems to be missed is that the DVD play back is influenced by the reliability of the laser diode. And that diode is subjected to thermal stresses far beyond those of the CD-ROM laser diodes. At the junction temperatures used in DVD burners, the life of the diode is a small fraction of the CD-ROM diodes. It also deteriorates in performance from the junction breaking down. Consequently the playback life of the player is significantly reduced. Yet it is always the media that takes the hit. Everybody else seems to have lots of horror stories about media. I don't. I want to again state that I have seen CD's burned in the 1976-77 time period that can still be read. And I've seen DVDs from the early 90's that can also still be read. Reliably. But the moves to cut the cost of the players to sub-$50 means that many companies are using substandard laser parts, or parts with shorter rated life (which are a lot cheaper.) Every study I have seen shows that CDs and DVDs have a much longer life span than magnetic media, especially floppies. Another point made that I do agree with - because of all the music CDs made, the players will not go away. All the major players in CDs and DVDs have tried for many years to force to another form factor. Those mostly empty 5.25" chasses are really offensive to design engineers trying to push the state of the art. And how can you resell the same music again, if you don't change form factor or format? But the customer base won't budge. They don't want to render obsolete their sizeable investment in CDs. (Last year I have data for shows annual production of CDs in the billions world wide!) Legacy demands will keep the 5.25" form factor around for the rest of my life. Can't speak for you youngsters. But say another 25 years minimum. Shame really - I saw some lovely little Blu Ray 20mm disks that held as much video as the current DVD. Gives you a DVD player that could be built into a cell phone or toy. But every customer survey showed massive resistance to change from 5.25". PVC does outgas Chlorine - and other volatiles. Does nasty stuff to the reflective films in DVDs. Most jewel cases are better. But oddly enough, the self cleaning paper sleeves caused the least affects - except for shock events. Billy

18 years, 2 months

SunOs tapes

by silvercreekvalley＠yahoo.com

Looking for any original SunOS tapes (any machine) or a 4.x era Sun 3 CD. Must be original tape/CD. Format etc doesnt matter as I can cope with just about anything. Also - if anyone is looking for the fairly difficult to find fuses that you get in Sun 3's I have a few spares available (no charge, just postage). I've blown a few of these fuses over the years, usually caused by the keyboard plug moving in the socket while the Sun is on - and I've found them awkward to find. Cheers Ian. ____________________________________________________________________________________ 8:00? 8:25? 8:40? Find a flick in no time with the Yahoo! Search movie showtime shortcut. http://tools.search.yahoo.com/shortcuts/#news

18 years, 2 months

Tektronix terminals [was: Re: Re: Humpty Dumpty]

by rickb＠bensene.com

>> I don't think Tektronix ever made a terminal that wasn't graphics >> capable :-) and when they went to raster displays from storage scopes, >> I believe they were all color capable. >I remember at least on counter-example, the 4025. It was a >mono raster unit. We had a 4025 at the research lab of the >first company I worked for out of college. It was connected to >one of those electrostatic printers. We drove it from a VAX 11/750 >running BSD4.2 and later 4.3. There was also a 4023 "non-graphic" terminal, significantly prior to the 4025. It used SSI and MSI TTL logic, early IC-RAM (don't know if it was dynamic or static), and a MOS character generator. The CRT used a rather slow-responding white phosphor that made it a little difficult to read when it scrolled. When I was a Systems Operator (as they were called in those days) of Tektronix' Scientific Computer Center Control Data Cyber 73, a Tek 4023 terminal was situated next to the big dual vector CRT console. This terminal was logged into KRONOS (the timesharing operating system that ran on Tek's Cyber 73) as an administrative user that would pop up messages with user requests to do things like mount tapes, and other messages from users, and the operator could respond through this terminal. The 4025 came significantly later, and I believe, was microprocessor controlled. The coolest Tektronix terminal, if you ask me, was the original Tek 4002. It did use Tek's famous DVST (Direct View Storage Tube) display that was really made famous by the 4010. The 4002 (and slightly updated) 4002A were big terminals, with a "drawer" packed full of electronics. The coolest part was the "^G" (bell), which was a really nice tone generator. I can't remember if it was a hack, or production, but there was an escape sequence that you could send to change the frequency of the tone emitted with control-G was received. With this, people had written some programs on some a DEC PDP-8 (it may have been a PDP 8/I IIRC) that could play music on the terminal, while drawing some graphics on the screen at the same time. There also was a 'write through' mode, again, not sure if it was a hack, or part of the production terminals, that would (within the limitations of the RS-232 port) could do simple dynamic (non-stored) vector graphics. There was a little game, again hosted on the PDP-8 machine, that would play a game where two tanks opposed each other with interposing landcape (hills or elevation changes) and players would take turns aiming their gun, and shooting a shell at the opposing tank. I also recall that for high-speed use, there was a direct DMA parallel interface that would hook to a PDP-11 (Unibus) that allowed some actually fairly high-performance vector graphics on the 4002. Would love to find a 4002 or 4002A around somewhere. Would also love to find one of those 4023's -- it really was a great old terminal. For a time, I had one of them at home, hooked up to an acoustic coupler and I could dial into the Cyber at 1200 baud, and do work from home. Those were good old days! Rick Bensene The Old Calculator Web Museum http://oldcalculatormuseum.com

18 years, 2 months

Humpty Dumpty

by ken＠seefried.com

From: Richard <legalize at xmission.com> > >> As an aside, INMHO E-bay feedback is seriously broken, in that you can >> bet seller will give you negative feedback if you give him negative >> feedback, no matter how poor the product, how misleading the discription, >> how promptly you paid, etc. > >In fact this seller tried to blackmail me saying "if you remove your >negative feedback, then I will remove mine, > I've not had this, but I've had a *lot* of sellers (almost always big ones) who have sent me mails to the effect "I'll leave you positive feedback after you leave me positive feedback". I don't leave any feedback for them. As a slightly amusing aside, the only negative eBay feedback I have was from this Canadian douchebag dentist-in-training who was pissed I left him neutral (not negative) feedback that it took something like 3 weeks to ship two small packages. Not only did he leave me negative feedback, as some sort of juvenile "payback" attempt, he tried to subscribe me to a couple of dozen random mailing lists. Of course, every one sent me a "reply to this if you want to subscribe" email, which I ignored. Now, as it happens, I was a principle information security architect for a Very Large Telco at the time. There's a certain amount of pull associated with the job. Not being real bright, our eBay dork didn't notice some of the mailing lists involved were hosted at .gov sites. They we're more than willing to supply me with date/time/IP of the attempt to sign me up. Very easy to track back to some jerk in Canada rather than me in sunny Atlanta, GA. This resulted in a few personal calls to his school and ISP to the effect "I'm a senior security guy at Very Large Telco, but I have a little personal issue I was hoping you could help me out with...here's the issue, here's the evidence". They apparently had a really good time dressing this little putz down. Moral of the story...don't try to screw random strangers. You never know what kind of pull they have.

18 years, 2 months

Humpty Dumpty

by Billy.Pettit＠wdc.com

Chuck Guzis wrote: True, high-voltage (low current) DC is usually far less dangerous than AC, but there can arise nasty side effects from the involuntary muscle twitch. When I was much younger, I was working on a 3KV transmitter power supply. I *thought* that the bleeder had sufficiently discharged things, but it wasn't so. I brushed the top of an oil capacitor and got nailed. Unfortunately, about 6 inches in back of me was a concrete block wall. The muscle contraction proceeded to slam my elbow with great force into said wall. It hurt like hell for days. I'm fortunate I didn't fracture something. It's truly amazing how many lessons you can learn in the space of a millisecond or so: 1) Never trust a bleeder--they can and do open. 2) Leave plenty of working space around you. 3) Try to work with one hand in a back pocket. Cheers, Chuck ------------------------------------------- In the Army in 1960, I took radar school at Fort Monmouth, New Jersy. After Basic Electronics, we moved to the TPS-1D radar lab for orientation. 4 hour safety class - what to wear, to do, not do, etc. For example, we all wore a small florescent tube on our shirts. At the end was a tour and the instructor pointed out the various systems and risks. We got to the kylstron modulator and he pointed out with a wooden pencil where the high voltage lead was. Of course the inevitable happened, the arc came up the graphite, and his muscles convulsing threw him into wall. A few of us had sense enough not to laugh. The MSgt in charge of the lab came running over and helped him back on his feet. He asked the instructor what the hell happened? This guy was still in a daze and answered, "I don't know. All I did was touch this point with a pencil like this..." The next day he left for Fort Dix for infantry training. Billy

18 years, 2 months

eBay - Interesting Item

by aek＠bitsavers.org

> $50 is overpriced for an ICE? It's useless without the CPU pod.

18 years, 2 months

eBay - Interesting Item

by Billy.Pettit＠wdc.com

6809 Emulator stuck over in ICs. Overpriced but nice looking. 150089377880

18 years, 2 months

← Newer
1
...
24
25
26
27
28
29
30
...
39
Older →

Jump to page:

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2002

2001

2000

1999

1998

1997

test-drb February 2007