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Re: old computers
Hugh Prescott
Yesterday got a call from a metal fabrication plant that I had helped figure out some RS-232 problems commuincating with a CNC turrnt punch several years ago. Big sucker 12 inch holes in 1/2 inch plate steel at about 30 per second.
Big piles of steel plate waiting to be punched, it's a RUSH repair. Had the computer that is used to upload the punch programs go down. Compaq ProLinnea 486SX with 200Mhz Pentium Overdrive chip, 20 Mb RAM and a 270 Mb hard drive and a 3.5 floppy. Hard drive was totally dead. No CD ROM drive in this all in one box. Found an old but good WD 345 Mb drive, made up power and IDE drive cables to run the CD drive outside the case. Found the USB CD ROM version of Win 95 and then the special boot floppy to install Win 95 on systems that will not boot from a CD. Took more than 3 hours to find all the stuff, get it all together and load Win 95 but it all came together. Drove it out to the plant and hooked it up. Loaded their punch control software and loaded a job to punch. Everything worked like a charm. They think I am a freeking hero. Hugh Never throw anything away ever. |
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Re: EProm burner
Leon Heller wrote:
That's because it is a fuse-PROM. 256x4 with tristate outputs, cross-references to the Signetics 82S129.Does anyone have an Eprom reader and burner available? I need to have aI don't think that is an EPROM, it looks more like a fusible-link PROM. -- Phil. | (\_/) This is Bunny. Copy and paste Bunny ygroups@... | (='.'=) into your signature to help him gain | (")_(") world domination. |
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Re: old computers
Hugh Prescott
Chuck
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I have a working DecWriter wide carriage L120-DA sitting here looking for a home. It's in Quincy IL , 100 miles north of St. Louis. Prefer it be picked up. Last used as a lineprinter on a Novell network. Complete tech manual included. Hugh Chuck Harris wrote: Hi Arthur, |
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Re: EProm burner
Leon Heller
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----- Original Message -----
From: "Joe Gisler" <gislerhj@...> To: <TekScopes@...> Sent: Thursday, February 08, 2007 5:29 PM Subject: [TekScopes] EProm burner I don't think that is an EPROM, it looks more like a fusible-link PROM. Leon -- Leon Heller Amateur radio call-sign G1HSM Yaesu FT-817ND transceiver Suzuki SV1000S motorcycle leon355@... |
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Re: First post - Hello and a question
Dennis Tillman
Rockland Instruments (later bought by Wavetek) made a fabulous FFT based
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spectrum analyzer for the 7000 series scopes. It is the 7530A/B. They show up on eBay about once a yaar. The last one sold for less than $100. Dennis -----Original Message-----
From: TekScopes@... [mailto:TekScopes@...] On Behalf Of Greg_A Sent: Wednesday, February 07, 2007 9:25 PM To: Kuba Ober; TekScopes@... Subject: Re: [TekScopes] First post - Hello and a question For audio band distortions you just need what is called Wave Analyzer (in other words spectrum analyzer) in 5Hz -50kHz. I own one with some same spare - HP analyzer for audio band. Any scope is not capable to "see" small distortions.... Greg |
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Re: old computers
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-----Original Message-----There were two computers in the dusty storeroom at the University of Portland in 1978: the 1620 I would rescue from the scrap dealer, and a PDP-8/e + 4010 + TU56. Someone had built a custom interface that allowed the PDP to read paper tapes using the 1620's paper tape reader, which could load PAL-8 at 150 bytes/second, 15 times the speed of the ASR33 that sat abandoned in the corner. This is in turn much slower than my early-1970's Remex paper tape reader. It's interesting to compare technologies. The ASR-33 was 100% mechanical, and read tapes by poking at them with spring-loaded pins. Any pin that went through was a 1. The 1621 (1620 PT reader) uses photodiodes, but still drives the tape with a pinwheel which furnishes the clock output. The electronics are discrete PNP Ge transistors. The Remex uses TTL. It shrank the photodiodes enough that they could slip a ninth one between 4 and 5 to read the feed hole directly, and it runs the tape with a rubber capstan drive, at twice (maybe 4x - I can't remember) the speed of the 1621. ObTek: I brought up the 1620 with the aid of a 535. I heard later from one of the original IBM design team that they used the same model when they were bringing up the product for the first time. ObTek2: The custom interface used Tek-numbered transistors. And they weren't the ubiquitous -0188/-0190 (2N3906/4). Dave |
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Re: old computers
From: TekScopes@... [mailto:TekScopes@...]OnMy first job was at a small laser scribing/trimming shop, and my first task there was to build a plug-in board for a PDP-8/e that would interface to an X-Y positioning table. I remember how well-written the DEC manual was, and how straightforward the circuit design. The interface took me only a few days and worked the first time. I'm not bragging - it was mostly thanks to DEC. Later when I was doing custom mods for Tek's Information Display division, I regularly assembled terminal firmware on an 11/45 running RSTS. Collecting a printout, I would often snag on the front panel lights, just gazing mesmerized as they went through their tail-chasing idle pattern. Nearby was a small photo lab, with a "RotoTrack" (sp?) lightlock door. Some wag had put up a picture from the Woody Allen movie "Sleeper" showing Woody emerging in a somewhat disorganized state from the "Orgasmatron", which bore an uncanny resemblance to the Rototrack. Dave |
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Re: tek 4051 computer
From: TekScopes@... [mailto:TekScopes@...]OnAround 1980, I used a 4051 day in, day out. It always seemed like a friend. Another department had a 9825A. I poked at it a few times, but found it quite impenetrable. Dave |
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EProm burner
Joe Gisler
Does anyone have an Eprom reader and burner available? I need to have a
74S288 read and 4 pieces burned with the same image. I am happy to pay one of the group to do it for me. Thanks in advance Joe Gisler Dr. H. J. Gisler Vector Associates 3580 N Barkley Road Apache Junction, AZ 85219 480-288-6660 480-288-6661 fax 480-206-4999 cell gislerhj@... vectorassociates@... |
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Re: dpdt slide switch for sc501 int/ext trig select switch
arthurok
try deane kidd
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----- Original Message -----
From: Jerry Massengale To: tekscope group Sent: Thursday, February 08, 2007 10:36 AM Subject: [TekScopes] dpdt slide switch for sc501 int/ext trig select switch Greetings, I have a need for a small slide switch(tek part number 260-1470-00). The part was made by Illinois Tool Works inc., pn 23-021-309. The ITW web site search does not respond to that number. That really t's me off when manufactors drop references for old products. If someone has a source or cross-reference, please respond. Jerry |
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dpdt slide switch for sc501 int/ext trig select switch
Jerry Massengale
Greetings,
I have a need for a small slide switch(tek part number 260-1470-00). The part was made by Illinois Tool Works inc., pn 23-021-309. The ITW web site search does not respond to that number. That really t's me off when manufactors drop references for old products. If someone has a source or cross-reference, please respond. Jerry |
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Re: Japnease Transistor
REX ATHEY
2SC2909 RF, AF Silicon EP NPN Vcbo=180volts Vceo=160volts Ic=70mA Pw=600mW fT=150Mhz in grounded base operation basic specs from my 1986 Japanese transitor manual.
Consolidated Electronics has them for 38 cents each or 10 for $2.80 in the US. They also list an Alternate type as being 2SC1473 which is listed as 250 Volts - collector / base 200 Volts - collector / emitter 70mA collector current 600mWatts and an fT of 80 MHZ in grounded base operation. Rex |
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Re: AM501 Stuff (op-amp references)
Kuba Ober
On Wednesday 07 February 2007 19:05, you wrote:
Thanks. You beat me to the second question! I did wanna know if IWell, the deal is this: there's no easy way to get performance out of a better chip if you have large, uncontrolled and *variable* parasitics. That's what your hand waving is :) The way to fix it is to use your op amp in the circuit, not in the plugin. A faster op-amp may even start oscillating just from the fact that it's inside of the AM501 wiring harness. Probably the only road to improvement is to use a similarly slow op-amp, but a more DC-accurate one. The AM501 is not really useable for much beyond simple school-type experiments. It wasn't meant to be! It was specifically designed for use in educational setting AFAIK. I have lots of unused OP177 chips, if you want a few just let me know off-list. They are good replacements for 741 and friends -- similarly slow, but much more precise. Cheers, Kuba |
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Re: old computers
Chuck Harris
Hi Arthur,
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I am currently using a laptop to act as the console terminal. It works just fine, but then again, the laptop works better and is decades faster than the 8/E, so might just as well not use the 8/E at all! I am looking for a console terminal that is age appropriate to the 8/E. A 4010, or 4012 looks nice, and was used on 8/E's in the research world. At least the 4010 is built with ttl chips, like the 8/E. A DecWriter or ASR33 would be more authentic, though. -Chuck arthurok wrote: i like dec tape drives and the tu56 was a very good one |
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Re: First post - Hello and a question
Kuba Ober
On Wednesday 07 February 2007 18:39, you wrote:
My late father used to say "Why do it simply, when complicated worksI guess it was "Warum einfach wenn Mann komplizieren kann" or somesuch. My German is pretty rusty. To me, using an unknown scope is complicating things. Mind you, I wasn't anywhere advocating a full calibration -- just a decent enough check to make sure that your 100MHz mainframe and preamps are where they are supposed to be. Maybe my problem was that I was almost always getting the mainframes and plugins separately, and the plugins were always in lots and always seemed to be someones "reject" pile. 90% of them calibrated just fine, though. I guess the proper advice would be: get a 7603 with plugins, coming out of service in a lab somewhere, with a calibration sticker with dates in last 7-8 years. That'd be safe enough I guess. Kuba |
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Re: First post - Hello and a question
Kuba Ober
You don't NEED anything like an RF RMS voltmeter. or phase detector. AHmm, I've been tuning a lot of 2nd order 500Hz low pass Bessel filters and the most accurate way of tuning them was to tune for proper phase at cutoff frequency. IIRC it was supposed to be 45 debgrees. Frankly said, I don't quite know how else I'd go about tuning them anywhere near same accuracy - you can detect small phase changes very well, while detecting the peak of amplitude response *to the same accuracy* is kinda hard. I've seen a similar thing in narrow bandpass filters: the peak of the response is where your amplitude envelope slope is zero, so by minimally tweaking the tuning you get close to zero change in amplitude. So the only way I found to do such tuning with good accuracy was to look at phase. But then I didn't really have much RF experience, so I may be talking complete BS. I'm only relating what has worked for me. Cheers, Kuba |
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Re: First post - Hello and a question
Greg_A
Well Johnny,
You already discover the name of the game. I did that some year ago looking onto Ebay stuff... Now with (I think) 5Hz min BW and 100dB dynamic range how it is not "good enough" to read audio distortions dB down (max up to 100dB down) from the carrier? I think this HP machine is as powerful as todays Microwave Spectrum Analyzers with similar parameters dealing with RF. Greg At 04:43 AM 2/8/07 -0800, Johnny Chapman wrote: <> Emacs! |
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Re: First post - Hello and a question
Johnny Chapman
Greg, ahhhhhhhhh the HP 3581A. Read that they are
good thingies. The price on 'em is good too. I'd prefer a 3580A w/ the crt. However, they aren't that great at S/N measurements of some modern digital sources and killer amplifiers. I'd really like to know how an Tek AF501 would compare to the 3581A. You can surely get an 3581A more cheaply and consistenly. Yeah! Audio Discussions on my B-Day! 33 years old! Hee Hee; I'll be 40 and dirt before ya know it (definitely no age bashing here; just little fun; I respect age/wisdom and wanna live way out yonder!). Laters. ____________________________________________________________________________________ Want to start your own business? Learn how on Yahoo! Small Business. |
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Re: First post - Hello and a question
Johnny Chapman
Thanks for the post Ash!
Check the specs on the Sencore SG80. I believe it to be a bit better and a younger product by maybe ten years. I hardly use it, but when needed, BAM! I generally am brand loyal almost to a fault! I've first seen them in the install/maintenance bays of GM dealerships. AC/Delco is the parent company of Rockford-Fosgate! ____________________________________________________________________________________ Yahoo! Music Unlimited Access over 1 million songs. |
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