test-drb July 2006

test-drb@ccmp.vtda.org

204 participants
377 discussions

by mouse＠Rodents.Montreal.QC.CA

Back in the late '70s and early '80s, I used a particular oscilloscope, a "TYPE 304 H" "CATHODE-RAY OSCILLOGRAPH" from "ALLEN B. DUMONT LABORATORIES, INC., PASSAIC, N.J., U.S.A." (all quotes come from the front panel markings). It worked fine then. After sitting idle for years - probably at least a decade - I've got my hands back on this 'scope. It doesn't quiet work, but appears to be close. It's an entirely vacuum-tube design; even the power-supply rectifiers are valves rather than semiconductors, and all the wiring is point-to-point, with terminal strips used as necessary and most components self-supported by their leads. (I mention this to give some idea of its age.) When I turn it on, it appears to power up. All the filaments light as far as I can see (the one I can't see is the CRT, and since I get some light on the screen under some circumstances, I infer its filament is working too). But I can't find the beam. I've set both X and Y selectors to "off", which (based on my past experience with this 'scope) should give me a single stationary dot. If I crank the intensity all the way up, I get vague shadowy patterns of light on the screen, but no matter how I play with the X and Y position controls, I can't get anything definite. The Y position control does something; the X position control does not, as far as I can tell from watching the screen. What memory I retain (which may be wrong) indicates that this display syndrome is typical of a beam which is far off-screen in one direction or another, but doesn't give any hints for what to do if the position controls don't work. Any thoughts? I googled, to no avail. Since the wiring is point-to-point, I could trace out a schematic. I will if I have to, but I'm hoping that the above symptoms is enough for someone to point me in a useful direction to look for the problem. Unfortunately I have only minimal test equipment available - a moderately-decent electromech voltmeter is about it. Since the X position knob does nothing, I speculate that that pot has gone bad and is, in terms of the circuit it controls, always hard over against one margin. Does this sound plausible? I may try to find the deflection electrodes and apply the voltmeter to them, if it has a suitably high range (I'd not try it unless it has a range of at least a kilovolt). Yes, it'd load the driving circuit more than it's designed for, but glassfets are mostly pretty resistant to that sort of thing, and the loading alone may well bring the beam back on the screen if that's what's wrong. /~\ The ASCII der Mouse \ / Ribbon Campaign X Against HTML mouse at rodents.montreal.qc.ca / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B

19 years

Identifying cctalk messages

by hadsell＠blueskystudios.com

I find it difficult to distinguish some cctalk messages from spam. The From: could be anyone, and the Subject: is not always technical enough to recognize. Could your mailer add '[cctalk]' to every subject, if it is not already there? This would also enable a filter to send the message to a cctalk folder. It's a technique that I have seen with other e-mail lists, and I like it. -- Dick Hadsell 914-259-6320 Fax: 914-259-6499 Reply-to: hadsell at blueskystudios.com Blue Sky Studios http://www.blueskystudios.com 44 South Broadway, White Plains, NY 10601

19 years

Hobby / museum activities

by nico＠farumdata.dk

Hi all We frequently talked about a conversion service, where those having the proper drives, could help amateurs / museums in preserving / conserving their data. Before I incorporate this page in my normal web site, I'd like to hear comments, and where possible the names/websites of others who are interesting in helping our community. The way I see it, this page should only refer to relevant parties, who then (on their own website) can have a description of what they can be of assistance with. Please take a look at http://www.farumdata.dk/uk/enmuseum.asp I would appreciated your comments Nico

19 years

NetBSD and old hardware curiosity

by cclist＠sydex.com

After watching an 800MHz P3 system build Gnome (and its dependent packages) on a NetBSD system, I got to wondering how usable NetBSD is on older slower hardware, such as MicroVAX II. If you want to build Perl or X or the kernel, what do you do? Start the make and come back in a week? Cheers, Chuck

19 years

Checking before I scan...

by rcini＠optonline.net

All: I'm cleaning up the shop and I found a few Commodore manuals I want to scan but before I do, I wanted to check and see if anyone's done this already. I have the service manual for the 2031LP floppy drive, the user's manual for the 2040/3040/4040/8050 drive (I have an 8050) and the service manual for the PET 4016/4032. Let me know if these exist already. Thanks. Rich Rich Cini Collector of classic computers Lead engineer, Altair32 Emulator Web site: <http://highgate.comm.sfu.ca/~rcini/classiccmp/> http://highgate.comm.sfu.ca/~rcini/classiccmp/ Web site: http://www.altair32.com/ /***************************************************/

19 years

IBM 1800 rescue

by bobalan＠sbcglobal.net

For those interested, I rescued an IBM 1800 computer system last weekend. It appears to have been built in 1967 and has been maintained running until about two years ago. It has a simulated 2311 hard drive (using an older PC) and a 1442 card read punch. Came with a full set of documentation! Some photos can be seen at: http://dvq.com/1800/1800.htm I hope to put together a list of the manuals and microfiche and the more than 1000 SLT modules that came with it. Hopefully I can get it up and running again. Bob

19 years

hp 16500A software

by lbajger＠wp.pl

Hello, ive found yours posts on some discussion board in internet. http://archive.netbsd.se/?ml=cctech&a=2002-12&t=153839# I need software (inverse assemblers, os etc.) for hp16500A could you send all you have to me ? Please. regards LB

19 years

1710 vs 1620

by michael_short＠comcast.net

The 1710 was an upgraded 1620. It had hardware to handle interrupt processing. There were features on the 1710 that were ordereable on the 1620 such as A/D conversion and rudimentary bit manipulations. I think that the 1710 could also handle a small number of terminals.

19 years

FW: please forward if of interest: free Televideo luggable, Berkeley, CA

by javickers＠solutionengineers.com

Best Regards, Adrian Vickers. -----Original Message----- From: John Hauser [jhauser (at) jhauser.us] Subject: please forward if of interest: free Televideo luggable, Berkeley, CA I'm not a subscriber of cctalk (nor do I want to be), which I believe means I can't post to the list. However, the following might be of interest to your subscribers: There is an old Televideo luggable being given away for free in Berkeley, California. It's at the street curb along with some other free junk in front of 1213 Channing Way. Unfortunately, I don't know the model number or operating condition, but it looked intact. It had evidently been kept by some kind of hobbyist (judging from the other junk), although not exactly a collector. Includes two built-in 5.25" floppy disk drives, if that helps in the least. Didn't want it to be thrown away if it might be gold to one of you. - John Hauser -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.394 / Virus Database: 268.9.9/382 - Release Date: 04/07/2006

19 years

IBM 1800 Rescue

by brian＠quarterbyte.com

> Hard to believe that under all of that, lurks the heart of an 1130! Actually, it turns out that that's not quite true. We heard some of the history of the 1800's development from Neil Hillier, this 1800's former owner. He was on the design team. While the 1800 has the same instruction set as the 1130, the CPU's hardware design was done by a different team to meet different performance goals, and thus the implementation is not the same. We're hoping to give Neil a formal and thorough grilling, er, interview for ibm1130.org after he's finished his move to Montana. Brian =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- _| _| _| Brian Knittel _| _| _| Quarterbyte Systems, Inc. _| _| _| Tel: 1-510-559-7930 _| _| _| Fax: 1-510-525-6889 _| _| _| Email: brian at quarterbyte.com _| _| _| http://www.quarterbyte.com

19 years

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test-drb July 2006