test-drb January 2004

test-drb@ccmp.vtda.org

290 participants
643 discussions

by dwight.elvey＠amd.com

Hi Actually the thought of a tube based computing isn't all that far fetched. I read an article about creating tiny tube circuits that use emission form a tiny nano wires end to create free electrons that can then be used for things like gates or flipflops. The voltages and power levels are quite small. Still, I find it hard to see how even a small tube can work faster than a 90 nm transistor. The biggest speed issue we have today is the external wiring and not the gate speeds. Dwight

20 years, 11 months

Cromemco SCC Eproms

by pete＠dunnington.u-net.com

On Jan 20, 14:23, Joe Abbott wrote: > Does anyone have images of Rom 0 and Rom 1 for > Cromemco SCC S100 single board Z80 computer? I'm very disappointed to find my SCC's single EPROM appears to be something the previous owner made for his own purposes -- it only has 36 bytes of code in it. Sorry, Joe. I guess this one was bought without the monitor/BASIC ROMs, which were optional. So now we both want an MCB-416 EPROM set (or images). On the plus side, I've found a 4FDC floppy controller manual (and a couple of 16FDC manuals). I'd like to get the 4FDC manual scaneed. Could anyone in the UK do this for us? It's 46 8.5" x 11" pages, plus one double size schematic. -- Pete Peter Turnbull Network Manager University of York

20 years, 11 months

Modern Tube computing

by dwight.elvey＠amd.com

>From: "R. D. Davis" <rdd(a)rddavis.org> > >Quothe John Lawson, from writings of Tue, Jan 20, 2004 at 03:55:27PM -0500: >> And no one has had the utter madness to suggest a replica of the Mark I >> or II relay machine..... or the SSEC.... or any of the Bell System relay >> computers.... > >Relays don't normally glow, alas, but they do make nice sounds. > >My preference is for a digital computer using water instead of >electricity, but no one's mentioned one of those yet. > Hi Actually I've given quite a bit a thought about making a computer that uses marbles instead of electricity or water. You'd put a bucket of marbles at the top and turn the crank. Gravity would bring the mrbles to the bottom where one could scoop them up and recycle. Dwight

20 years, 11 months

Advice on electrostatic deflection CRT ?

by melamy＠earthlink.net

forgive any inaccuracies to those who may know better (or can remember better...)... what you will be interested in finding out is the deflection per inch voltage required for the beam deflection. I seem to remember ranges of 10-50 volts per inch. You will need to know the filament voltage of course and its amperage. What I don't recall is what the necessary acceleration element voltages were. The grid was used to control the beam brightness with a greater negative voltage with regards to the other elements dimming the beam (I think). The electrostatic plates should have the beam in center with zero volts and then deflection is accomplished by positive and negative voltages. If you can not find precise data then you can find the full deflection voltage by experiment once you have a center beam. I suspect that the long tube should give you a more sensitive tube in that the deflection voltage may be on the low end of the range. best regards, Steve Thatcher Original Message: ----------------- From: Tom Uban uban(a)ubanproductions.com Date: Wed, 21 Jan 2004 09:50:46 -0600 To: cctalk(a)classiccmp.org Subject: Advice on electrostatic deflection CRT ? Hello, I have what I believe is a custom CRT. It has a 12" round face, is approximately 20" long, and uses electrostatic deflection. It was manufactured by Thomas Electronics Inc. in Wayne NJ and is hand marked as model number 12E35P31, 12-2-78. I am hoping to put this CRT into service and need to come up with a set of specifications which will likely work with it. What other physical information do I need to take from the CRT in order to help determine the specifications? Any suggestions for creating the power supply and deflection drive electronics are welcome. Thanks! --tom -------------------------------------------------------------------- mail2web - Check your email from the web at http://mail2web.com/ .

20 years, 11 months

M7891 switch settings? (univus)

by aek＠spies.com

www.bitsavers.org/pdf/dec/pdp11/MP00672_MS11L_engDrw.pdf

20 years, 11 months

power cord for 11/34?

by pete＠dunnington.u-net.com

On Jan 21, 11:56, Brad Parker wrote: > > The end of the power cord is snipped off this 11/34a I have in front of > me... > > It has a blue wire, a brown wire and a green striped wire. > > I'm assuming the green striped is ground. Brown hot and blue neutral? > > (I think this is a standard, but I shy away from voltages above 48vdc :-) That is indeed the standard in Europe. -- Pete Peter Turnbull Network Manager University of York

20 years, 11 months

4 PDP-11's found (plus RK05's) and VAX 7000 !

by msokolov＠ivan.Harhan.ORG

Fred N. van Kempen <waltje(a)pdp11.nl> wrote: > Nobody wanted the VAX 7000, so I'll try to take some pictures of it, > before it visits the Evil Melter. Well, if no one can take the whole machine, can you at least pull all XMI (and VAXBI if any) cards out of it before it's melted down? I would want those, and would even be willing to pay for them (depending on what it has, if any). MS

20 years, 11 months

Advice on electrostatic deflection CRT ?

by dwight.elvey＠amd.com

Hi He can most likely test it out by jumpering it into an oscilliscope. Most use electrostatic deflection. Dwight >From: "melamy(a)earthlink.net" <melamy(a)earthlink.net> > >forgive any inaccuracies to those who may know better (or can remember >better...)... > >what you will be interested in finding out is the deflection per inch >voltage required for the beam deflection. I seem to remember ranges of >10-50 volts per inch. You will need to know the filament voltage of course >and its amperage. What I don't recall is what the necessary acceleration >element voltages were. The grid was used to control the beam brightness >with a greater negative voltage with regards to the other elements dimming >the beam (I think). The electrostatic plates should have the beam in center >with zero volts and then deflection is accomplished by positive and >negative voltages. If you can not find precise data then you can find the >full deflection voltage by experiment once you have a center beam. I >suspect that the long tube should give you a more sensitive tube in that >the deflection voltage may be on the low end of the range. > >best regards, Steve Thatcher > > >Original Message: >----------------- >From: Tom Uban uban(a)ubanproductions.com >Date: Wed, 21 Jan 2004 09:50:46 -0600 >To: cctalk(a)classiccmp.org >Subject: Advice on electrostatic deflection CRT ? > > >Hello, > >I have what I believe is a custom CRT. It has a 12" round face, is >approximately 20" long, and uses electrostatic deflection. It was >manufactured by Thomas Electronics Inc. in Wayne NJ and is hand >marked as model number 12E35P31, 12-2-78. > >I am hoping to put this CRT into service and need to come up with a >set of specifications which will likely work with it. What other >physical information do I need to take from the CRT in order to >help determine the specifications? > >Any suggestions for creating the power supply and deflection drive >electronics are welcome. > >Thanks! > >--tom > > >-------------------------------------------------------------------- >mail2web - Check your email from the web at >http://mail2web.com/ . > > > >

20 years, 11 months

neat 20 year birthday of the mac page! http://www.digibarn.com/stories/mac20/index.html

by esharpe＠uswest.net

http://www.digibarn.com/stories/mac20/index.html

20 years, 11 months

FF: IBM Displaywrite 5, and CA Supercalc 5

by julesrichardsonuk＠yahoo.co.uk

Any takers for these before they go to landfill? Both are boxed with manuals and 3.5" media. Cambridge, UK... as y'all know :) cheers Jules

20 years, 11 months

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test-drb January 2004