test-drb January 2011

test-drb@ccmp.vtda.org

130 participants
209 discussions

OT: step down voltage converters (part deux)

by brianlanning＠gmail.com

Can some of you EE types talk about the (in)efficiency of stepdown transformers? Like say a 2000 watt 220 to 110 transformer. How bad are they? brian

13 years, 3 months

MC14500 / was Re: ENIAC ....

by shoppa＠trailing-edge.com

Brent asks: > Are there any known examples of real-world products or equipment that > used the 14500 ? > (Leaving aside evaluation boards & such.) I've seen it used in railway interlocking control panels and HVAC applications from the early 80's... places where PDP-14's had previously been used and it's pretty obvious the design was done from ladder logic principles. Interestingly, a certain generation of GRS interlocking control panels used PC boards and backplanes exactly matching the format of quad-height DEC modules. I never traced out the backplane wiring but at first glance it was nothing like Q-bus or Omnibus. > I had the impression of it as a bit of a stillborn product, like the > Fairchild CMOS Macrologic series (34700/4700 ICs), of limited > cost-effectiveness or benefit by the time it was introduced. There were many bitslice families out there that never saw wide use or maybe only existed in databooks. After the 2901 everyone tried to jump in. The MC14500B at least was obviously not a 2901 clone :-) Tim.

13 years, 3 months

Data I/O Unipak 2B ?

by scanning.cc＠gmail.com

I just bought a Data I/O 29B with an Unipak 2B from Epay. Everything seems okay BUT the pinout cartridge ( the little module that plugs in the end of the 2B ) is missing. I suspect that all it has is some kind of simple interlock like two pins tied together to tell the Data I/O the cartridge is there ( probably so you can't run the unit with that HAZARDOUS 20 volts on the open connector. Anybody know how to get around this or fake it ? The unit won't do squat without it.... Have not been able to find a schematic of the 2B or the pinout cartridge. Thanks. Best regards, Steven

13 years, 3 months

The Ultimate Computer

by trebor77＠execpc.com

Imaging an Alien Being totally non-Physical but infinite in Nature capable of Computing. Aren't our Brains Computers of a sort.??? They take in Inputs from all the Parts of our bodies. Process that information and act on it. Producing Output to our Optical Part of our "BRAIN" in response to sensory Input from our Optical Sensors ;"EYES",? If we see Food we eat it if we are "HUNGRY". The same can be said for all of Nature. It reacts to Sensory Input and outputs a Response. Birds can sense the Magnetic Field of the Earth and Guide themselves accordingly They also can sense the Position of the Stars and Navigate from them. The Monarch Butterfly must have a Built in Programmable ROM as when One generation flies South to Mexico in the Fall the same Individual does not make the Return trip but instead Produces Offspring along the way but those Offspring find there way back to there "HOME" Port unfailingly as does the Fingerling Salmon who traveled down the Columbia River. In Essence every thing that "MAN" has Discovered or Invented already existed in the Natural World in some Form or the Other "Food For Thought" Now theres a handy "Thought" And in closing "All Computers Need a Programmer" even a light switch. Pair up 3 and you have a "3-Way Circuit" which when activated turns on the Appropriate light. I even had a Four Way installed in my Basement. I Just added an "X" Crossover in the Circuit at the bottom of the Stairs. Works great. Turn it ON at the Top of the Stairs and you can either Turn it OFF at the Bottom or Turn it OFF over by the Sink in the Laundry Room then turn it back ON from the Bottom of the stairs for the return trip. If one used Motion Sensing Switches then One would not have to even Streach out his Hand to flip the switch. Start with 256 Switches and a Diode Matrix and you have the Makings for a Home Brew Computer. Just add circuits to each Output of the Matrix and you can control up to 255 Devices. CRUDE but effective. Replace the Devices with Logic Circuits and before you know it your Computing. Now that's Computing.

13 years, 3 months

How many ICs does it take to put a man on the moon

by shoppa＠trailing-edge.com

Brent mentions Atwood saying: > The question about the moon landing is why haven?t we been back. > And it was done in an age where computers were as big as a couple of rooms. > If you even look at the Space Odyssey 2001 HAL the computer, and I think > that movie came out in the late 60s, HAL the computer is huge. > We didn?t yet have microchips. So I just wonder, how did they do that? > Why they haven?t done it again if it was so easy? My day job is a computer that has a $10 Billion (1980's dollars) peripheral. In other words the computer isn't the end goal :-). To think that the computer is the peripheral, sometimes trips up even the senior execs. Really the computer only exists to help the peripheral :-). Getting back to Atwood's babbling, I don't remember JFK promising to land a computer on the moon by the end of the decade. And BTW, we have sent computers to the moon, and landed them on Mars, many times since then, all in the goal of space science, not in the goal of sending computers there :-) Tim.

13 years, 3 months

How many ICs does it take to put a man on the moon

by hilpert＠cs.ubc.ca

Here's a funny story. Margaret Atwood, famous Canadian woman of letters (writer, novelist, "The Handmaid's Tale", "Oryx & Crake", etc.) was heard in an interview on a high-school radio program to be questioning the Apollo moon landings. It's not quite clear whether she believes it was a hoax, whether she was hoaxing the hoax, just encouraging kids to question things, or later backpedalled to avoid embarrassment. One version: http://fullcomment.nationalpost.com/2010/09/23/margaret-atwoods-just- wondering-about-that-silly-moon-landing-hoax/ What makes this topical to the list though, is one of reasons she gave to question the landings: The question about the moon landing is why haven?t we been back. And it was done in an age where computers were as big as a couple of rooms. If you even look at the Space Odyssey 2001 HAL the computer, and I think that movie came out in the late 60s, HAL the computer is huge. We didn?t yet have microchips. So I just wonder, how did they do that? Why they haven?t done it again if it was so easy? Later, after backpedalling a bit, she still says: But the questions about the computer technology needed to do something this complex remain with us? what were they using, in those days before microchips? How heavy was it? Apparently it only takes 40 years, not 2000 (Antikythera), to start questioning whether our 'forebears' were able to do things without the tools we have today. And she was publishing in the 60s, it's not like it was all before her time.

13 years, 3 months

CHM's "Revolution" opens this morning

by aek＠bitsavers.org

One of the things I've been working on for the past five years. http://venturebeat.com/2011/01/13/that-old-computer-in-your-garage-is-histo…

13 years, 3 months

Would a bog-standard 4164 be a suitable replacement for a MCM4517 in a Sega SC3000H? (was Re: Introduction - Terry Stewart (tezza))

by ethan.dicks＠gmail.com

On 10/19/10, Mike van Bokhoven <mike at fenz.net> wrote: > Hi Terry, > > Welcome to the list, from another NZ classic-cmper. Whereabouts in NZ are > you located? Hi, Terry, I'm curious, too. I've spent about six months of the past 15 years in NZ, mostly in Christchurch, with trips to Wellington, Auckland, and Hamilton. > I also enjoy getting dead machines going; my current challenge is finding > RAM for a Sega SC3000H. I was hoping someone might have some spare MCM4517s > for sale (from memory, hopefully that number's right), Those are just +5V-only 16Kx1 DRAMs, right? The pinout is the same as the 4164 except for pin 9 (NC on a MCM4517, A7 on a 4164). Could you use a 4164 instead? (it might require a pull-up or pull-down on pin 9 so it doesn't float). Those are rather abundant and still available from a number of sources. -ethan

13 years, 3 months

Computers & Chess

by jwest＠classiccmp.org

A local museum wants me to see if an exhibit can be put together pertaining to Computers in Chess. We wouldn't be looking for just "a row of microcomputers playing chess", we'd be looking for items of historical significance, firsts, etc. That being said, we need items of interest to novices as well as experts. The duration of the exhibit would be somewhere between 3 and 6 months, definitely not a permanent exhibit. The museum would of course pay for professional shipping of items and insurance. The floor space available for the exhibit could be up to 4000 sq/ft if need be. Anyone have parts of Deep Blue? ;) Would any listmembers have items of significance/interest to Computers in Chess, and be willing to loan them to the museum for this exhibit? If so, please email me off-list and if we can use it, I'll send you a copy of the museum's facility report (which details security, environmental controls, professional handling, etc.). I'd also appreciate any ideas/pointers for exhibits or places to check for items of interest. Thanks in advance! Jay

13 years, 3 months

Kindle and bitsavers?

by wbblair3＠yahoo.com

All of my relatives have gone with Nooks rather than Kindles for themselves and their children, primary reasons being that the Nook supports the ePub open ebook format and Barnes and Noble ebooks are cheaper than Amazon's. Less important is the capacitive touchscreen. Early firmware for the Nook had issues, new versions are fine. This is what they tell me anyway since I don't own one myself nor have I paid much attention to ebooks.

13 years, 3 months

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test-drb January 2011