test-drb July 2012

test-drb@ccmp.vtda.org

196 participants
250 discussions

by jonas＠otter.se

On Sat, 7 Jul 2012 20:21:13 +0100 (BST), ard at p850ug1.demon.co.uk (Tony Duell) wrote: > One of my hobbies at school was disrupting lessons by asking nasty > qeustions _on the subject of the lesson_. Point being had they kicked me > out for doing that, my parents would have exploded with the school > Seriously. > > I once walked out a physics lesson and said I would only return when the > teacher had actually learnt some basic physics. That did not go down > well. But, you know, I am still waiting for a defintion of a (scientific) > measurement that does not involve comparison to a standard. > > I think the problem was more with the school than the teacher, they should have got a teacher who knew the subject. Sadly, there is the same problem here. A lot, if not most, of the primary and secondary school teachers-to-be here do not know even basic mathematics. The University here (the one which produces engineers and Ph Ds in engineering, physics and chemistry) added an extra year to the M Sc courses long ago, so as to allow the students to catch up with the maths and physics. Even in the early 1970s, the curriculum in the UK up to O-levels was at least a year ahead of that here in Sweden; I went to a school for a year in Yorkshire when I was 15 (5th form) and during that one year I had to catch up with half the 4th form maths and physics, in addition to doing the 5th form syllabus and taking O-levels. When I came back I learned no new maths, physics or chemistry for the 3 years at school here until I went to University. I should have stayed on in England. /Jonas

12 years, 5 months

Film Recorders (Agfa PCR II)

by Arno_1983＠gmx.de

ard at p850ug1.demon.co.uk (Tony Duell) wrote: > > > (...) it displys TV-rate video on an > > > internal CRT and photographs it. > > > > > > There's a colour fitler wheel (red, green, blue and a hole) so it cna > > > print a colour inamge in 3 goes. > > > > (...) > > AFAIK mine only does NTSC-rate video (OK, for the pedants, RS170 rate > video), there is certainly no itnernal framestore. (...) there's a disk > with 4 filters (one clear, maybe just a hole) and a stepper motor to > move them. There is some kind of control board, I seem to remember it's > microprocessor based,. maybe even an 8080. And not much more. I don;t > rememebr there being an internal NTSC or PAL colour decoder. So it must takes RGB component input (no decoder) and you have to feed it a "freeze frame" video signal, i.e. keep the image content static (no framestore) until the three exposures have been completed? > (...) As I mentioned, the optics is a standard, and not very > good (Soligor, I think) enlarger lese. It's essentially fixed focus > (well evetyhing is at a fixed distance, so that's OK), it's fitted to a > meatl tuve which slites into the camera body and is lcoked by a > setscrew. Presumably you can focus it if necessary when you repari the > unit. > > I also got what looks ot be a home-made bracket with it. 'Home made' > meaning not a Polaroid product, I suecpt it was made in the workshops of > the university I got this thing from. This fits in place of the Polaroid > camera. It looks like it would have held a35mm SLR + motordrive (...) OK, so making a camera adapter in a "normal" workshop is confirmed to be possible. Apart from interfacing the signals, it looks as if the most complicated part of it was somehow joining the camera body, the lens and the distance tube in a mechanically solid and light-tight fashion without messing up the distances between the components as you go. > Err, yes... I think if I was going to make this, I would start wit ha > dead electronic SLR, though. On the grounds it has interchagealbe lenses, > a motor to wind the film and solenoids to open/close the shutter. Then > remove the dead electroncis and make my own cotnrolelr. Whether I'd leave > the mirror in palce I don;t know, it might be easier to do so if the > sugger mwchanism depends on it for the corraect sequece. Seems like a very sane approach. I'll have to see what I can come up with, as I know for sure I don't have a broken SLR in my junk box... > Well, an enlarger lens is typically used to enlarge :-). What I mean is > that the distance from the front to whatever (paper in an enalrger) is > longer than the distance from the back to whatver (negative in an > enlrager). So if you put the CRT where the paper would be and the film > (in the cmaera body) where the negative should be, it'll work and > produce a reduced image of the CRT on the film. > > That sounds like waht yuu want. Ahh, I see. I had something backwards but now I can't see what it was... Thank you so far, Arno.

12 years, 5 months

WTB DECserver telnet Terminal Server

by markbenson＠mac.com

As the subject suggests, I am looking for DECserver to go with a VT510 that will allow me to telnet to hosts without a full 'middle-computer'. If available also some ports to hang serial connections (MJ11 or d-series) to would be great too. -- Mark Benson http://markbenson.org/blog http://twitter.com/MDBenson

12 years, 5 months

Poor Steve is dead, poor Steve Jobs is dead...

by john＠yoyodyne-propulsion.net

On Thu, Jul 5, 2012 at 7:47 AM, Mark Benson <md.benson at gmail.com> wrote: > A lot of people are already touting them as having designs on the TV and entertainment market. > Another Apple TV will go over like a Lead Zeppelin. (Then again, the Newton was a disaster so maybe they will get it right this time.) -- Yoyodyne Propulsion Systems: "The Future Begins Tomorrow" Visit us at: http://www.yoyodyne-propulsion.net -------- Doctor: You know when grownups tell you, "Everything's going to be fine" and you think they're probably lying to make you feel better? Amelia: Yeah. Doctor: Everything's going to be fine.

12 years, 5 months

Today, in the bus to work...

by elson＠pico-systems.com

cctalk-request at classiccmp.org wrote: > Date: Tue, 3 Jul 2012 21:07:39 +0100 (BST) > From: ard at p850ug1.demon.co.uk (Tony Duell) > To: cctalk at classiccmp.org > Subject: Re: Today, in the bus to work... > Message-ID: <m1Sm9Nx-000J4TC at p850ug1> > Content-Type: text/plain > > >> .. I overheard two teenage girls examining each other on tech history. >> >> Girl A : "The first PC was ....?" >> Girl B : "...the Macintosh !" >> Girl A, looking in her textbook : "Correct !" >> >> Sigh....... >> > > ARGH!!!! > > >> Of course "first PC" is open to debate, but a Mac ? >> > > Can anyone give a resonable justification fo that answer. I actualyl > can';t think of anythign the Mac was 'first' for. > The Mac was the first MASS_MARKETED computer to use a mouse to steer a pointer on the screen. Of course, the Xerox Alto was the prototype of that. As for first PC, how about the Bendix G-15? Vacuum tubes, drum memory, and it sure only ran one program at a time, sometimes for weeks! Or, IBM 1620. Then, there was the LINC, about 50 were built in 1965, 2 K 12-bit words of core memory, discrete transistors, and a dot-drawing screen for editing online. Reel-to-reel mag tapes to serve like disks. And then the Altair 8080 and SW Tech 6800 machines. Jon

12 years, 5 months

HP1630D, IBM "M" keyboards, PRO 350 or 380

by useddec＠gmail.com

My sons are helping me clean out one of my 25 foot storage lockers. I knew there was a little computer in this one, but it looks like about 1/3 computer items. Today I found two HP1630D logic analyzers, one of which has 7 pods. 4 IBM "M" keyboards, maybe 5 or 6 caps missing. PRO 350 or 380 missing cover, has RX50. I'll try to look at it tomorrow. I do have other 350 and 380 units and parts. Feel free to contact me off list if you have any interest. Thanks, Paul

12 years, 5 months

Lisa Experts: Lisa 1.8A power supply test?

by wheagy＠gmail.com

Can anyone recommend a quick (safe) way to test a Lisa 1.8 amp power supply outside of the Lisa chassis? It appears that something (maybe pin X) needs to be jumped to make some of the power supply function outside of the Lisa? The only pin I currently get a reading from is pin 20 (~5.62v) which appears correct. I'd like to test more of the supply, if possible, prior to powering up the Lisa. Pointers appreciated. http://imgur.com/idthc http://imgur.com/PcFF6 Thanks, Win

12 years, 5 months

which (Northstar?) computer used the Fujitsu M2551A 360k floppy drive?

by rampaginggreenhulk＠yahoo.com

I have one

12 years, 5 months

DEC Flat Panel

by elson＠pico-systems.com

Date: Sat, 07 Jul 2012 11:24:28 -0700 From: Eric Smith <eric at brouhaha.com> To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> Subject: Re: DEC Flat Panel circa 1987 Message-ID: <4FF87EDC.50201 at brouhaha.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Peter C. Wallace wrote: > > Sure its plasma? Planar specialised more in EL and that yellow looks > > like EL to me > > My recollection was that DEC used a plasma panel, but I could be wrong. > I agree that the color in the photo is consistent with EL. Wow, you could be right, I'd completely forgotten about Planar! Jon

12 years, 5 months

Philips P800 progress...

by iamcamiel＠gmail.com

Hi Everyone, I'm making some good progress with the Philips P800 minicomputers. I'm anxious to get an operating system running on them, and lack of working disk drives (I haven't been able to get one of the X1215 cartridge disc drives going yet), has pushed me in a somewhat different direction. I found an image of an X1215 disk pack containing a DOS version 5 installation on Theo Engel's website. I have implemented a very basic X1215 emulator in an FPGA PCIe card. Together with a small piece of software, and a cable with the necessary level converters, the emulator presents the X1215 disk images to the disk controller in the P800. The software is responsible for loading the image into the FPGA's memory buffer one track at a time. This now works to the point where the initial part of the IPL works correctly. Four sectors are read from disk, after which the P800 displays a "MONITOR?" prompt. After typing "DOM", there is another flurry of disk activity, then nothing. No "** DOS 05 **" banner. I noticed that the disk emulator never asks for anything other than track 0, so there is probably an error in the implementation of the SEEK command. To be continued...

12 years, 5 months

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test-drb July 2012