- test-drb@ccmp.vtda.org - classiccmp.org

by compoobah＠valleyimplants.com

> Is there a > good tutorial somewhere that explains how capacitors are used for > decoupling and smoothing? (I've checked some obvious sources, but I > need more detail, like if you connect a cap to a +5 source and ground, > why doesn't it just discharge completely ...) > Look at a book dealing with the design of PSUs, or a introductory electronics course. The basic rundown is this: Capacitors and inductors have reactance across them when fed A.C. Reactance is an opposing force that works against the flow of current, in this respect it's similar to resistance, but resistance is the same across all frequencies, reactance varies (for a given reactive load, X(L) (inductive reactance) goes up as frequency increases, X(c) (capacitive reactance) goes down. Impedance is the combination of reactance+resistance. For a DC supply with ripple, you can think of it as 2 mixed components: a DC component and an AC component. The capacitive reactance is chosen to present a low impedance path to the AC component so it travels through the capacitor rather than into the chip. Inductive reactance figures in because (as mentioned) the traces have inductance, and the capacitor also has inductance (so a large capacitor to smooth a high-frequency AC component might not be the best choice- all of that metal provides inductance that opposes the flow of the AC component). Help any?

19 years, 1 month

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crimp-on D-sub pin removal

by compoobah＠valleyimplants.com

> Nowadays I might consider making yet another adapter and rewire the > modular side by using a cat5 patch cord and a dual modular jack, wiring > the jack with the crosswires as necesary. requires very little by the > way of tools, and keeps everything else original. I would have considered that had these been anything special, but I got a bunch of these adaptors from my dad's dental office when they were moving off of their Xenix system (with the Xenix system as well). They are not wired to any standard I know of, and they don't even seem to be wired to the same standard within the lot. I remember fervently wishing that they had used a MicroVAX instead of a PC with SCO. I also wished that I had been paying attention when they were getting rid of the Altos, but that was when I was in 4th grade.

19 years, 1 month

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crimp-on D-sub pin removal

by compoobah＠valleyimplants.com

I am somewhat flummoxed- I have a 8-pin modular to DB-25 adaptor that I need to move some pins on to make if functional with a 3B2 machine, but looking at the unused connector positions I can't figure out what the retention device is for the installed pins to remove them. It doesn't look like a Molex-style clip coming from the pin (2 pins are uninserted) and there doesn't seem to be any catches molded into the plastic. Any pointers on how to pull these pins with standard garage tools?

19 years, 1 month

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crimp-on D-sub pin removal

by compoobah＠valleyimplants.com

> Only if your garage comes standard with the D-series pin puller tool. > :) > > If you've seen the tool for some variant of molex connector, you've > seen > the principle: a thin-walled split tube which slides down around the > pin, inside the socket, and shoves the plastic retainer bits out of the > way. > > For a picture: > > http://www.tecratools.com/product1199.html > > De The picture didn't help much, but the basic description did (I've never used a Molex pin removal tool, every Molex I've worked on has succumbed to a dental pick in short order). It is possible to remove these with basic garage tools: all you need are a small piece of thin sheet aluminum and a moderate precision 5/64" metal dowel- in short an aluminum soda pop can and a 5/64 drill. Form the aluminum into a tube with a slot suitable for 24 ga wire, put around the pin, pull out- all in less time than it takes to drive to the semi-local electronics store.

19 years, 1 month

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VCF Midwest 3.0 thoughts

by ISC277＠CLCILLINOIS.EDU

I had an excellent time this year as usual, even though we initially had some unforseen problems getting rolling toward Purdue. Lots to see, and I had a fun time socializing(and on occasion brainstorming) with those I don't see nearly often enough. The speakers were great and very entertaining, and Rick did a great job coordinating dinner for Saturday night. As an exhibitor, I have to say that the turnout was way better than I thought, especially on Sunday. Thanks to everyone involved for making this not only a success but an entertaining endevour as well. Looking forward to 4.0! Julian

19 years, 1 month

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LEO (1950)

by RodSmallwood＠mail.ediconsulting.co.uk

I happened on the program by chance. It might have been called Disappearing Britain. A lot of it was contemporaneous and could have been a Lyons publicity film. (or at least bits of one). I suspect our friends at the National Film Archive might know. I inadvertently made an ambiguous statement. By commercial I meant its use, not its availability for sale. Where would you start to design such a thing? Valves yes.. 12AT7 Bistables as binary counters. Neon devices such as dekatrons as decimal counters. RVL (Resistor Valve Logic). Storage = Ferrite Cores, Tape, Drum possibly. I once saw a Univac FAST RAN Drum memory. What a lump!!! Rod -----Original Message----- From: cctech-bounces at classiccmp.org [mailto:cctech-bounces at classiccmp.org] On Behalf Of Jules Richardson Sent: 16 July 2007 22:45 To: On-Topic and Off-Topic Posts Subject: Re: LEO (1950) Rod Smallwood wrote: > I just caught a part of a TV program showing pictures of and the use > of a computer called LEO. That wasn't the James May thing that aired last Tuesday was it? I think it was something along the lines of 'the history of science', and I wondered what they'd show for origins of the computer - sadly I wasn't around when the show was on though to see. > Anybody know of another real commercial electronic computer before 1950? Hmm, the Ferranti Mark 1 (based on the Manchester Baby) was a commercial machine and built around that same sort of time. I'm not sure if the Ferranti machine was the first to be sold to someone (rather than being used in-house) or whether the LEO was. (Actually, I'm not sure if LEO I was ever used outside of Lyons - I think it may have been the later LEO II that was their first true commercial machine) cheers Jules

19 years, 1 month

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1966 Mag: Build NE-2 Neon Bulb Computer - scan available

by James＠jdfogg.com

> Subject: Re: 1966 Mag: Build NE-2 Neon Bulb Computer - scan available > > > It relies on matching the neon bulbs. > > Ha! Matched for how long? After a month, I bet no two matched > ones are matched anymore! > > At least the little voltage regulator tubes (0D3 and friends) > age better. Would zeners be a better choice?

19 years, 1 month

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Wanted-VAX and items

by starmaster＠gmail.com

I am looking for a Micro Vax (or any VAX) and/or materials/literature on them. I live about 60 miles south of Denver, and do not have many $$ to invest, but will do what I can. Anyone have any they are willing to part with? I would also dearly love any old Commodore equipment/literature as well! Thank you David

19 years, 1 month

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Vol 47, Issue 28, message 10, Subject: LEO (1950)

by mike＠brickfieldspark.org

> I just caught a part of a TV program showing pictures of and the use of > a computer called LEO. > It was made by and belonged to a UK company called Lyons. > They imported and sold tea, ran a chain of tea shops and restaurants, > made and sold ice cream. Leo eventually became ICL, I worked for them (ICL) on LEO III-26 at Charles House in London on payroll and utility billing, my experience was on Ampex TM2's & 4's which the Leo's uesd. The "scope" was on the engineers panel and was for monitoring the memory, it displayed as blocks of 4 bits - 0000 0000 0000 - forget how many coloumns, in a strange variant of hexadecimal, but the days before hexadecimal became the norm. There is an interesting website for LEO's at - http://www.leo-computers.org.uk/pageone.htm - including all the installations.

19 years, 1 month

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LEO (1950)

by RodSmallwood＠mail.ediconsulting.co.uk

I just caught a part of a TV program showing pictures of and the use of a computer called LEO. It was made by and belonged to a UK company called Lyons. They imported and sold tea, ran a chain of tea shops and restaurants, made and sold ice cream. I should know, my father worked for them and we had our own ice cream freezer just like shops. Boy were we popular in the summer.!! Any way LEO (Lyons Electronic Office) took four years to build and was up and running in 1950. They showed a large room with closed racks, a console with meters and a scope of some sort. Also a punch and printer machine room. Two applications were featured. A tea blending system and a stock control system for the tea shops. The tea shop application was telephone to punched card in real time. Each teashop had a phone in time slot. >From there it printed picking lists, allocated the stock and even did a van route setup with LIFO loading. It must have been all valve and would need cooling. However Lyons was an ice cream company and refrigeration would not have been a mystery to them. To quote an American actor "I have got to get me one of those!!" Anybody know of another real commercial electronic computer before 1950? Rod Smallwood

19 years, 1 month

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What AMP connector is this?

by charlesmorris＠hughes.net

As previously posted, I needed a power cable to connect my 11/23+ chassis to the power controller. The controller end was an AMP Mate-n-Lok and so is the one on the switch board at the front of the 11/23+. Thanks to Vince for the Mouser part numbers. But the connector at the rear chassis is NOT the same. Here is a picture of it (to the left; the Mate-N-Lok is on the right): http://tinypic.com/view.php?pic=6csdoiq The (DEC) cable is marked "70-18384-03 Rev A" and that connector "AMP-2" and "CPH-2". I just made a longer cable with a Mate-N-Lok on both ends, and ran it directly from the switch board to the power controller. Anyway I'm still wondering which connector I could have used, or if this is a previous-owner modification. thanks CHarles

19 years, 1 month

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Omnibyte OB68K/VME1

by lee＠geekdot.com

Omnibyte OB68K/VME1 I'm looking for any information on this board. This is a 68000 based 6U VME card and not the similarly named multibus card. Cheers. Lee.

19 years, 1 month

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hp tape inventory

by Robert.Smith2＠robins.af.mil

What is the possibility of getting a copy of a Punched Tape.....( 92060-16044 !DSKUP OFF LINE DISC BACK UP )? Robert Smith Process & Support Section Avionics & Instrument Division 402 EMXSS/MXVOPB(MAIPB) Robins AFB,GA (478) 327-8669 DSN 497-8669

19 years, 1 month

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Lilith computer running !

by aek＠bitsavers.org

> Which means that there is at least one machine with a complete set of > microcode and higher layers avaliable. Great news! > with at single RS232 channel, no software and a flat directorystructure > with over 500 entries, this looks also to be quite a task. By 'no software' do you mean no development tools? If there is some way to type out the contents of a disk block, you can slowly dump the whole disk. Binary dumps of all the files could be automated if there is a file dump program. > It does have ethernet, but it is the very old ( first ?) 3MB standard. The orig was roughly 3mbits, with 256 device addressing. The specs for what PARC developed exists, though I'm not sure that they exactly copied the design having never seen it.

19 years, 1 month

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Alto emulator progress

by aek＠bitsavers.org

http://pullmoll.stop1984.com/alto/ Juergen has made a lot of progress in the past month. There are some small movies up now of the simulation running games with user loaded microcode.

19 years, 1 month

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Free Commodores near Seattle (Seabeck), WA

by tosteve＠yahoo.com

Do not email me, see email address below: I have several old Commodore computers that are headed for the junk-heap unless I can find an appreciative collector. I have two VIC 20's, at least two C64s, and one C128. I don't know if ANY of them still work. I think I have some Commodore peripherals too. There may be a Commodore printer as well. I want nothing for them except shipping. If you are interested - or you know someone who is, let me know and we will work something out. Bill Sipple sipplewg at wavecable.com Seabeck, Washington, USA (98380) --------------------------------- Sick sense of humor? Visit Yahoo! TV's Comedy with an Edge to see what's on, when.

19 years, 1 month

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neon glow lamps (was TTL homebrew CPUs)

by dkelvey＠hotmail.com

>From: Brent Hilpert <hilpert at cs.ubc.ca> > >dwight elvey wrote: > > > > As a note on the dekatron, these were used in some of the early > > HP counters. They were used as the first, or highest frequency, > > state of the counters. They were quite fast! > > Dwight > >I beg to differ on this. I have a couple of dekatron counters and they >only seem to be good to some 10s of KHz (unless of course, you mean that >that >was pretty fast for the time). Interestingly, one of these counters uses >two >types of dekatrons, the only obvious difference between them being the >colour >of the glow and the part number. The ones in the slower speed decades are >the >usual neon glow, in the higher speed decade a purplish glow (xenon?). I >presume >the purplish glow gas ionizes faster than neon. >I should try to ascertain more accurately the max rate of the purplish deks >but haven't yet as one of the two in the unit is failing. > >I haven't seen dekatrons in HP counters, I believe their first counter was >the >524A and, unless it was radically different than the 524B/C/D, didn't use >dekatrons. Certainly the rest of the 520 series was vacuum tube flip-flops >(AC-4 modules). Hi Bret I recall that is was an HP counter. I don't recall the fastest count but it was on the order of either 10KHz or 100KHz. I don't think it was less then that but it may have been 1MHz. I recall that like many of the HP counters of the time, the other decades were the inline 10 ea bulbs. I don't recall if these were neon or incandescent but I think they were neons driven by dual triodes. I do believe that the ring counter did have a purplish glow. Dwight _________________________________________________________________ http://imagine-windowslive.com/hotmail/?locale=en-us&ocid=TXT_TAGHM_migrati…

19 years, 1 month

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Lilith computer running !

by jos.mar＠bluewin.ch

My interest in the Lilith computer has been restarted after some recent post to a.f.c. ( what a mess a.f.c. is...) I put in some extra effort and was rewarded with a Lilith that booted up into its Medos OS ( version 5.2) The last time this particular machine booted its OS was in 1990 . Which means that there is at least one machine with a complete set of microcode and higher layers avaliable. The machine remains VERY temperamental : Most attempts to boot end in disk softread errors, resetting the Lilith involves power cycling ( I looked for signs of a startupcircuit, could not find any ) Probably some diskplatter / head cleaning is due, not something I look forward too. And then there is the task of rescuing the data : with at single RS232 channel, no software and a flat directorystructure with over 500 entries, this looks also to be quite a task. That's right, the Lilith does not have a hierarchical filesystem ! It does have ethernet, but it is the very old ( first ?) 3MB standard. AFAIK it cannot be interfaced to something more recent. Jos

19 years, 1 month

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MODCOMP II Revisited...

by lbickley＠bickleywest.com

My excitement over getting my MODCOMP II running in June (reference post attached) - was somewhat "premature". The MODCOMP II performed well - and then started having intermittent failures. I observed that many of the failures seemed to be the result of badly seated chips. I thought that a bit strange, since I had checked them all as part of the restoration process. As time went on, the system became even more dysfunctional - until it wouldn't run even the most rudimentary programs. I checked with a former MODCOMP hardware support person - and he asked: "What brand were the failing chips you've found so far?". I hadn't even thought about that. He said "Let me know after you check - and I wouldn't be surprised if they were all TI (Texas Instruments)". I did check - and virtually 100% were TI chips. Factoid: Many TI chips produced during 1975-77 period had very thin "legs" and poor tinning. When they were wave soldered, the solder offered them protection. However, when they were socketed (as in the MODCOMP) they had very little protection from the environment. They would rust and eventually fail. He suggested that I just replace all the TI chips in the MODCOMP if I wanted a reliable system. I decided that was too "radical". So armed with a logic analyzer and scope, I began to debug the MODCOMP - one chip at a time. After finding 20 or 30 bugs - ALL of which were TI chips - I finally "relented". I have now replaced about one hundred and fifty TI chips in the Modcomp's CPU and memory planes. I'm about 3/4 of the way through the process - and the MODCOMP is becoming very reliable. It will run basic memory diagnostics by the hour without failure. Final thoughts: The "badly manufactured" TI chips turned out to be a lot more fragile than I had originally supposed. When I removed many of them from their socket, their legs would simply fall off. It wasn't unusual to have two or three legs fall off one chip! Some were incredibly rusty over their entire surface - which wasn't at all obvious looking at them from the top. The MODCOMP sockets were "good news - bad news". Bad, because the sockets exacerbated the TI chip manufacturing issue - and good, because they made the chips easier to replace! Regards, Lyle ---------- Forwarded Message ---------- Subject: MODCOMP II Rescue Revisited... Date: Monday 04 June 2007 21:06 From: Lyle Bickley <lbickley at bickleywest.com> To: "General Discussion: On-Topic Posts Only" <cctech at classiccmp.org> A number of you probably remember me "announcing" in Jan, 2007 that I had rescued a MODCOMP II/12 from a lab here in Silicon Valley. The link for that is below (sorry, it's slow - the pictures are large). http://bickleywest.com/modcomp.htm After a lot of work cleaning up both the CPU and I/O chassis I began checking out the system. It turned out that the I/O chassis was in pretty bad shape. I went back to the lab facility where I found the MODCOMP II - looked through several more buildings - and found another lone MODCOMP II I/O chassis. I went through the "salvage" process again - and finally picked it up about a month ago. It was in a lot better shape than the original I/O unit. And the really great news - it was an identical configuration to my original I/O chassis. After cleaning it up, doing all the usual capacitor, power supply checking - I powered it up - and everything "looked" good - and no bad "cooking" smells ;-) I cabled up the CPU and I/O unit, powered 'em up - and to my amazement the front panel controls seemed to work O.K. I then did the usual hand memory tests - and core memory worked O.K. every location I tested. I then wrote a bunch of small diagnostics (in machine code) - and found that I/O was not easy to code - but I did enough to check that the console in/out ports worked O.K. Today I loaded diagnostic monitors, and diags - and most of the system - including I/O is working! The really good news is that all 64K (words) of core memory passed the long manufacturing memory diagnostic - which even tests for "hot cores" failing. It's been months in the making this critter come alive - but it sure feels great when the diagnostics tell you that you are on the right track :-) Cheers, Lyle ------------------------------------------------------- -- Lyle Bickley Bickley Consulting West Inc. Mountain View, CA http://bickleywest.com "Black holes are where God is dividing by zero"

19 years, 1 month

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JFETs in logic circuits

by cclist＠sydex.com

Someone, about a week ago, asked about JFET use in logic circuits. It turns out that the questioner was a bit ahead of the times. There's a relatively new device called a G4-FET that's made up of a MOSFET and a JFET, has 4 gates and can be used to make a 3-input NOT- majority logic element. Read about the construction here: http://trs-new.jpl.nasa.gov/dspace/bitstream/2014/10067/1/02-2177.pdf And its use in logic here: http://www.freshpatents.com/Universal-programmable-logic-gate-and- routing-method-dt20070111ptan20070008013.php Cheers, Chuck

19 years, 1 month

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Looking for something to put in this space (PDP-11)

by charlesmorris＠hughes.net

Here's a pic of my PDP-11/23+ system with two RL02 drives. There is an empty space about six inches high below the second drive, as you can see. (In the rear is a power controller and a panel with 16 serial ports, although I don't have anything to hook up to them for now). http://i18.tinypic.com/4pc8sux.jpg I'm looking for either a blank panel to cover the hole, or maybe an interesting device I can fit there, if anyone has a suggestion? thanks Charles

19 years, 1 month

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UK computer history gets new home

by RodSmallwood＠mail.ediconsulting.co.uk

There is quite a lot more of what happened re the Japanese codes in the various books that have been published. The breaking of JN25 by Rochfort to reveal the plan to invade Midway Island and the susequent loss of three carriers by the Japanese has been the subject of books, TV programmes and films. Another coup was the decoding of Yamamoto's inspection plans and the shooting down of his plane at extrame range by US twin engined Lockheed Lightning fighters. Some of the Japanese codes were quite weak due the mistaken belief that the Japanese language and Japanese morse code provided a level of protection. (They didn't!!) As to the Germans. The Abwehr did break the allied convoy code and a forward mobile unit in North Africa had considerable success with Montgomery's radio traffic. They did that is, until overrun and captured. Rod Smallwood -----Original Message----- From: cctech-bounces at classiccmp.org [mailto:cctech-bounces at classiccmp.org] On Behalf Of William Donzelli Sent: 13 July 2007 00:53 To: General Discussion: On-Topic and Off-Topic Posts Subject: Re: UK computer history gets new home > What gets me a little is the comparative lack of recognition that all > the others working on projects like Colossus have received; Turing > still gets publicity (rightly so), but not much ever gets said about > all the others who were contributing effort and ideas. This is a very common problem, especially when dealing with wartime technologies and who gets the credit. Two of the big factors are state secrecy, and the old saying "the victor writes the history books". For the former, one can look at the breaking of the Japanese codes (purple being the most famous). The Enigma and Lorenz stories are now pretty much out in the open and declassified, but the Japanese stuff is still locked up in secrecy. Under the veil of secrecy, the guys that did the work can not get the credit. For the latter, one can see just how little (almost no) credit is given to the Axis powers. There is very credible evidence that Allied codes were broken during World War 2. It is likely the Germans had some sort of equivalent of Bletchley, but is probably forever lost. The Allies were not about to give credit to the Axis engineers. Many still will not. It is bothers you - then speak up. Give the guys credit. Spread the word. They deserve it. -- Will

19 years, 1 month

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VCFmidwest v3.0 begins

by jwest＠classiccmp.org

Greetings folks... from West Lafayette, Indianna. The weather is awesome this morning, the day the festival begins. I arrived around 7:30pm local time last night and met up with Pat. He was able to get me into the exhibit area to set up my HP 21MX. I called a few people to see about dinner/drinks but was unable to rouse anyone by 10pm when I was free. I'm in the hotel room getting some documents together for handouts on the 21MX/E at the show (the poyner article as well as some technical spec sheets). I'll run to Kinkos a few blocks up the street and print them off momentarily. Then it's off to a big breakfast and then exhibit hall. Remember - doors open at 10:30am, speakers at 11am, and exhibits from 2pm to 6pm. I suspect that like in years past, most of us will head out to dinner this evening. Hope to see you at the show! Jay West

19 years, 1 month

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Bringing up an Altair 680...

by wh.sudbrink＠verizon.net

I've just been given access to an Altair 680. It seems to be in excellent physical condition (no rust, corrosion, dents... just some dust). Has not seen power in many years. All of the ICs are socketed. Due to the fact that the PS is incorporated onto the main board, I was planning the following: 1) Remove the main board from the case, detaching it from the front panel board. 2) Remove (carefully noting their positions) all of the ICs from the main board. 3) Attach dummy loads (24V light bulbs) to the PS at convenient locations. How many should I use? 4) Attach to AC power in this state. Assuming nothing pops, check DC voltage (voltages?) with a scope. Assuming DC looks good, allow to warm up for a few hours. 5) Scope check DC again. Power down allow to cool for a few minutes. Repeat steps 4 and 5 a few times (3? 4?). 6) If all looks good, reinstall all of the "easy to replace" ICs and do 4 and 5 again. 7) If all looks good, reinstall the rest of the ICs, restore the main board to the case and front panel. 8) Debug any logic problems (dead chips, opens, etc.). Does this look reasonable? Thanks, Bill No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.476 / Virus Database: 269.10.4/898 - Release Date: 7/12/2007 4:08 PM

19 years, 1 month

3
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Tandy 1000EX in Craigslist, Morgantown, WV

by us21090＠yahoo.com

I'm not associated with this person. See: http://morgantown.craigslist.org/sys/366079794.html Reply to: sale-366079794 at craigslist.org Date: 2007-07-03, 8:07PM EDT Tandy 1000EX [8086 processor] purchased in 1985, I think. Has dot-matrix printer; mouse; joystick; 1200 baud modem; internal and external 5 1/4-inch floppies plus an external 3 1/2-inch floppy. Monitor and stand. Games and other programs. I hate to just throw it away or e-cycle it. Pic available on request. Make an offer. ____________________________________________________________________________________ Shape Yahoo! in your own image. Join our Network Research Panel today! http://surveylink.yahoo.com/gmrs/yahoo_panel_invite.asp?a=7

19 years, 1 month

1
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Serel 1001

by cclist＠sydex.com

I don't recall ever seeing mention of this early French computer before. There's a great deal of photographic and documentary material here: http://pichotjm.free.fr/Serel/Summary.html Cheers, Chuck

19 years, 1 month

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Free in L.A.: Box of DEC Power, Serial, Printer, Telecom Cables, Adapters, Labels, etc

by molists＠yahoo.com

I have a large apple box of about 30-40 official DEC molded cables, i.e. console and null-modem (db9-db25, db25-db25, db25-centronics), printer and extension, as well as some non-DEC, a lot of standard power cords, gender changers, DB25 and DB9 test plugs, also includes three early manual device switches: 4-way RJ11, 4-way DB25, 6-Way DB25, a few classic free toys from McDonalds, and an angry nun. There are also several Avery-Dennison packs of 3.5" floppy disk stickers for 8.5x11 sheet printers, and there may be a set of 5.25" stickers. You pickup. ____________________________________________________________________________________ Don't pick lemons. See all the new 2007 cars at Yahoo! Autos. http://autos.yahoo.com/new_cars.html

19 years, 1 month

1
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RL02 Fault, not where you might suspect it

by charlesmorris＠hughes.net

I'm back from vacation (a wonderful time, except that for a week in mid-June southern Europe had an amazing heat wave - 43C/109F during the day in SW Crete, overnight lows around 33C/92F. Rumor has it that Athens saw nearly 50C/122F!). I have resumed work on my 8/A - RL02 - OS/8 system that booted only once (on the second power-up a buffer on the M8315 CPU board which drove memory address bit 4 failed). I'd previously posted my adventures finding that 74367. Anyway having fixed that it still wouldn't boot. The drive would load and the READY light would illuminate, indicating that track 0 had been located. When flipping the BOOT switch, the head could be heard to move, then the FAULT light would go on and the boot loader would hang. I did find that the disk pack had developed a bad block at octal 100, so I remade the image on a new pack with no bad blocks. Same error. So I put the pack in the drive that made it (on my PDP-11/23+) and ran the cable over to the controller. Still no go. I keyed in a couple of short programs and couldn't read the Command Register B properly. Sending one (or a loop of) reset commands (6600 octal) to the drive did not cause the FAULT light to go out - only power cycling the RL02 would clear it. That told me the controller was not communicating with the drive at all. With a few more test programs and the controller on an extender card, it was easy to see that the reset command was not being received, although the IOT 660x signal was. It turned out that the TP3 signal (required for the reset, among many other functions) was low in amplitude, barely 2V at the Omnibus pin CH2 (the other CPU timing pulses TP1,2,4 are well over 3V). The input buffer on the controller card was not responding to this weak pulse. Working backwards, I arrived at the source (E27-6 on the M8315 CPU, a 74120 Pulse Synchronizer). There's a pair of these, E22/E27, driving TP1..4 onto the Omnibus. Nothing obviously fried, but the other three outputs showed about 750 ohms to ground (on my Fluke 73) and the defective one was 57 ohms. Before desoldering the entire chip I confirmed it was defective by lifting pin 6 and it still had very low resistance. So the source of the RL02 FAULT is apparently a bad driver chip on the CPU board. Not where I would have first suspected it. There may well be yet another bad chip, but one error at a time... now I have to lay hands on a 74120 before my next 4 week trip away from home (leaving Sun. 22nd). Would anyone have one or two 74120's that you could drop in the mail tomorrow (I'll be happy to pay for the chip and postage), or point me to a supplier? Neither Mouser, Digikey, Jameco nor Newark have them :( and Unicorn Electronics has a $20 minimum order. thanks for any help -Charles

19 years, 1 month

1
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SGI Origin 2000 $600 OBO

by ethan.dicks＠gmail.com

SGI afficianados, Please contact the original poster, not me. AFAIK, the equipment is located in or near Columbus, OH. ---------- Forwarded message ---------- From: Scott Merrill <skippy at skippy.net> Date: Jul 13, 2007 9:18 AM Subject: [COLUG] SGI Origin 2000 To: Central OH Linux User Group <colug432 at colug.net> My former employer is looking to sell their SGI Origin 2000. If anyone is interested, please contact me off-list. Silicon Graphics Server 1 Origin 2000 DS 2xR10K195mhz 4 4 CPUs @ 195mhz XIO to VME Adapter, 6U 2 port Fibre Channel XIO Card XIO 4 Port 10/100 Ethernet Card Fiber Channel Vault Array 10 Slot Irix 6.4.1 OS 1 1000mb Network Card 24x CD-Rom Fibre Channel Cables 110 VAC Programming Terminal (crt is damaged however machine is operational) 10 18GB Fibre Channel Raid Disks 3 8.8GB FC Raid Disks 2nd FC Raid Vault 1 9GB Root System Disk 768MB ram Machine is fully functional, Fibre Channel, Raid, 4 port nic and GIGABIT. $600 OBO for the system above, it is definitely a workhorse! -- GPG 9CFA4B35 | skippy at skippy.net | http://skippy.net/ _______________________________________________ colug432 mailing list colug432 at colug.net http://www.colug.net/mailman/listinfo/colug432

19 years, 1 month

1
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Great little slide show on memories

by cclist＠sydex.com

On the IEEE Spectrum web site: http://www.spectrum.ieee.org/jul07/5337 It'd be fun to have the book that's mentioned in the text. Cheers, Chuck

19 years, 1 month

7
7
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TTL homebrew CPUs

by ed＠ed-thelen.org

Drifting from TTL homebrew computers into NE-2 relaxation oscillators - The year Sputnik went up - October 1957 - I built a Sputnik oriented Christmas tree ornament for my sister. The "earth" was 3" transparent plastic tube cylinder barely large enough to hold a selenium rectifier, small electrolytic capacitor, 47K resistors and disk capacitors. The transparent tube orbit had three support tubes, and contained the seven NE-2 gas tubes. I thought it cute but was disappointed that the start-up and operation was so unpredictable. Direction of rotation and number of satellites was variable. But my sister was delighted, and has it to this day - but it now goes on the tree only when I visit. Time has been unkind. The gleaming wires have turned ugly black, the plastic yellowed, the lamp cord dried and cracked, and I forget if it still works ... .

19 years, 1 month

2
1
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Burroughs B220

by aek＠bitsavers.org

> I would be interested in getting some good pictures of one, especially the console. I just put a bunch of scans up under bitsavers.org/pdf/burroughs/B220/brochure that should give you a good idea of what the machine looked like.

19 years, 1 month

1
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Bondwell Model 91

by marvin＠west.net

I just picked up a Bondwell Model 91 today, and have been unable to find any information about it on the web. A picture of it is at: http://www.west.net/~marvin/bondwell.jpg Anyone know anything about it? I am guessing it is part of an early televideo conferencing system since it has a camera mounted to the top. The "logo" on the bottom left says BWX compatible.

19 years, 1 month

2
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UK computer history gets new home

by feldman.r＠comcast.net

Just seen on the BBC Web site (http://news.bbc.co.uk/2/hi/technology/6291422.stm): "Plans are taking shape to set up a museum that celebrates Britain's role in the origins of the digital age. The National Museum of Computing will be based at Bletchley Park where World War II code breakers built the first recognisably modern computers. The museum's centrepiece is the rebuilt Colossus computer that broke high-level German communications during WWII. The museum's founders are seeking funds and backers to exhibit more machines from its extensive collection. " <more> Bob

19 years, 1 month

7
8
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3com 3c509b cards

by dgriffi＠cs.csubak.edu

I have a couple 3c509b ethernet boards for 16-bit ISA busses. Anyone want them? -- David Griffith dgriffi at cs.csubak.edu A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?

19 years, 1 month

1
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BCS at 50

by ljw-cctech＠ljw.me.uk

I've uploaded some photos from the BCS at 50 event at Bletchley Park today. http://www.flickr.com/photos/ljw/sets/72157600782178592/ It was a good day with interesting talks from Tony Sale, John Pether and John Harper. We got to see both the completed Colossus rebuild and the completed Bombe rebuild operating. Friday and Saturday the event continues in London. -- Lawrence Wilkinson lawrence at ljw.me.uk The IBM 360/30 page http://www.ljw.me.uk/ibm360

19 years, 1 month

1
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Software for Transtronics/Intronics EPROM programmer

by pierre-detorcy＠wanadoo.fr

I own a backup of the disk for the Intronics pocket pgmer. Do you still need it ?

19 years, 1 month

1
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Useful Information

by Billy.Pettit＠wdc.com

Al recently posted a useful manual for collectors. It is called the Fujitsu Sales Prospector 1986. I say useful because it contains a summary of all the industry's storage peripheral products available in 1986. Basic specs and some detailed specs on units. So, for example, if you need to know the differences between different Rodime hard drive models, that data should be there. At the end are several Fujitsu data sheets, on 5.25" and 8" hard drives and the 243X tape units. A handy manual for high level data on the state of the industry at that time. Billy

19 years, 1 month

1
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Looking for 5251 manuals

by fireflyst＠earthlink.net

Hi all, I'm looking for the switch settings and/or a service manual to indicate what the switches on the back of my 5251 do. Anyone have this data? Thanks Julian

19 years, 1 month

4
4
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TTL homebrew CPUs - OT radio

by ajp166＠bellatlantic.net

> >Subject: Re: TTL homebrew CPUs - OT radio > From: woodelf <bfranchuk at jetnet.ab.ca> > Date: Wed, 11 Jul 2007 14:52:31 -0600 > To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> > >Roy J. Tellason wrote: > >> Since a lot of parts like UJTs aren't ax commonly available as they used to be >> I poked around some and found stuff online as to how one might "make" one >> using a complementary pair of transistors. Couple each base to the other >> one's collector, and you have an SCR, an SCS, or a PUT, depending on how >> you wire it up. Not all that much difference between them... :-) > >Well I found this surfing last night. Fet + Pnp = Strange radio. >http://www.schmarder.com/radios/solidstate/homodyne.htm > That is a simple DC coupled amp that is used to first amplify RF then the detected audio is passed through again. The fet is for high input impedence and the transistor is for increased gain. Other wise know as a reflex receiver. Allison

19 years, 1 month

3
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VCF/Midwest 3.0 - this weekend - July 14/15!

by pat＠computer-refuge.org

There's just a few more days left until this year's Vintage Computer Festival / Midwest. So, come and see all of our excellent exhibits put on by computer collector hobbyists, listen to our speakers talking about vintage computer topics, and relish in the nostalgia by buying/selling/trading your own old computer gear at the VCF Marketplace at the event! VCF/Midwest 3.0 will be July 14-15, at Purdue University's Stewart center. Speakers will run from 11a to 2p each day, and exhibits and the marketplace will be open from 2p to 6p. Admission is $5 per day for access to the whole event, and kids 17 and under get in for free. For more details, and to sign up as a last-minute exhbitor or vendor, please see the official VCF/Midwest 3.0 website at: http://www.vintage.org/2007/midwest/index.php If you have any questions, feel free to send me a message at: vcfmw at computer-refuge.org. This year's VCF/Midwest is being sponsored by the Rosen Center for Advanced Computing at Purdue University - http://www.rcac.purdue.edu Pat -- Purdue University Research Computing --- http://www.rcac.purdue.edu/ The Computer Refuge --- http://computer-refuge.org

19 years, 1 month

3
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Looking for Eagle symbols for 2901 / 2911

by jos.mar＠bluewin.ch

If anybody has anything of the above, I would be interested. Jos

19 years, 1 month

4
5
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VCF/MW dinner

by pat＠computer-refuge.org

Anyone who's coming to VCF/Midwest and wants to meet up for dinner on Saturday, drop me a message tonight or early tomorrow. I want to get an estimate of how many people we're going to have, so I can potentially make a reservation. So, if you'd be bringing someone with you, let me know that as well. Thanks, Pat -- Purdue University ITAP/RCAC --- http://www.rcac.purdue.edu/ The Computer Refuge --- http://computer-refuge.org

19 years, 1 month

2
1
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CP/M for DEC VT-180?

by david＠marmotking.com

I stumbled across a very old post you made asking for CP/M disks for a VT-180. Did you ever find them? I know this is a REAL shot in the dark. I can't seem to locate them anywhere. I was able to find all the pieces to upgrade a VT-100 to a VT-180.

19 years, 1 month

4
3
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Victor 9000/Sirius 1 restoration questions

by jzg22＠drexel.edu

I have a Victor 9000 I'm restoring here, and I have a few questions: 1. Where do the two plugs for the 5 1/4 drive heads connect? This system has the Universal bios, a 10MB winchester HDD with DOS 3.1x and the later 1.44MB GCR/MFM floppy installed, but I can only seem to get one of the drive heads working (using catweasel on PC to dump a 'formatted' disk afterwards results in clear data spikes on one side and the other side blank, and format.exe won't format disks properly unless given the /1 1-sides flag) 2. The victor 9000 does NOT say anything when I turn it on. I know the Sirius 1 did, but I'm not sure the Victor does. Is this normal, or does the system need the HC-55564 delta modulation chip replaced? 3. Does anyone have a schematic or service manual for the victor 9000/sirius 1 anywhere? I also discovered that both of the victor keyboards I have need re-foaming between the contact discs and key plungers, which is gonna be a whole bunch of fun to do.</sarcasm> They also both need new snap-tabs on them as both of the tabs have the tooth broken off (though they work fine other than having to hit keys really hard and the cord occasionally falling out of the computer) Jonathan Gevaryahu jgevaryahu(@t)hotmail(d0t)com jzg22(@t)drexel(d0t)edu P.S. Does anyone have dumps of the older BIOSes for the system? The universal one is the 'last' one of at least three I know existed. More than one version of the universal one may exist. The one I have is labeled 'V9000 UNIV. FE F3F7 13DB' and 'V9000 UNIV. FF F3F7 39FE' with respective crc32s of 25C7A59F and 496C7467 for each ROM. The sum16s match the last part of the labels, i.e. 13DB and 39FE. P.P.S. does anyone have documentation for the winchester disk controller it used? I'm trying to make a raw binary dump of the hard drive, preserving partition tables, information, etc. and the only way I can see of doing it is to use BASICA to poke and peek at the proper memory addresses to make the disk do its thing.

19 years, 1 month

3
3
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Burroughs Terminal info

by stevew＠ka6s.com

Hmmm - the MT985 likely uses a polled protocol at RS-485 levels. It wants to hook up to the B1955 Multi-line controller fer instance. You would hang a bunch of these on a multi-drop line. The Multi-line would throw-out a poll sequence and get either an ACK or NACK from each terminal on the line. If the ACK happens, the terminal is then told to send in a block of data. If memory serves - it has 3 separate micros in it, and the software running on it was written in Pascal. These came out around 1981-2. Steve Wilson (worked on the B1955/B1965 design)

19 years, 1 month

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Need docs for Burroughs term (Jason T)

by alanp＠snowmoose.com

>>Being Burroughs, it may be VERY WEIRD. Sort of somewhere between smart >> (IBM) and dumb (DEC). It will probably only want to talk to a >> Burroughs. > >Hey, I like weird! But yeah...I'm getting the impression from the >manual this is not an ordinary serial term (though it does have an EIA >interface.) I don't think it emulates anything, except maybe other >Burroughs terms. It has been almost 20 years since I used that stuff, I did work on Burroughs on mainframe-PC integration and terminal subsystem stuff for three years, so I should remember some of it, shouldn't I? Almost no one was using MT-985 when I got there in 86. We all had ET-1100s and ET-2000s (a Burroughs PC clone that was also a Burroughs terminal). I don't recall them having any dumb serial terminal capability. It was a block mode terminal where the mainframe application would send down the form (a mix of text and formatting codes) in one chunk and the terminal would display it, then the use would fill in the fields and send it back to the application in a block when the user hit the transmit key. Electrically, we always used a two-wire interface (TDI or Two Wire Direct Interface). I recall that the connector was a DB-25, but only two pins were used, but that could just be bad memory. The protocol used to communicate with the terminals was called Poll/Select. It was half duplex. The terminal processor (can't remember what those were called in Burroughs-speak) would go through the terminals attached to it and query them to see if they had anything to send and, if a terminal did, it would. Given how hard it is to find info on Burroughs stuff these days, I wish that had saved more stuff when I left. alan

19 years, 1 month

3
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Symmetric 375

by aek＠bitsavers.org

Just checked, all of the files on ftp.berklix.com are gone Bernd Kopriva is on the list, hopefully he mirrored it. Dumping the boot proms would be a good thing.

19 years, 1 month

2
1
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trace wrinkles

by dgriffi＠cs.csubak.edu

I haven't heard anyone discuss this yet: what causes traces on some old PCBs to wrinkle and not others? My guess is a combination of suboptimal glue and wide temperature swings. -- David Griffith dgriffi at cs.csubak.edu A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?

19 years, 1 month

8
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Need docs for Burroughs term

by dm561＠torfree.net

------------------- Original Message: Date: Tue, 10 Jul 2007 20:47:36 -0500 From: "Jason T" <silent700 at gmail.com> Subject: Need docs for Burroughs term I've just picked up an old Burroughs terminal, model# appears to be MT-985, and I'm having trouble finding documentation for it. It came with a manual for the ET-1100 model which provides some clues, but the key sequences to get into the setup for baud rate, etc appear to be different. Anyone have any experience with these? It's a cute little terminal and the keyboard has a key lock on it - never seen that before. ----------------- Reply: Can't help with the MT-985, but if it's anything like its TD700/800 predecessors it probably had various interface options; the TD's could be configured for RS-232/BDI async, sync, IBM bisync or multipoint, and could also have cassette drives, a mag card reader and/or a printer attached. In case anyone has one, I do have tech manuals and some parts for the TD700 & TD800 terminal series. mike

19 years, 1 month

1
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Need Data Sheet

by Billy.Pettit＠wdc.com

I recently came across a stock of what seems to be 16 bit wide memory chips. But I'm getting nowhere trying to find a data sheet. Can anybody help out? The parts are UM61M512K-15, 32 pins DIP. The logo is round, world shaped with 3 vertical and 3 horizontal lines. Date codes are 95 and 96. The parts were on some mini-486 PCBs. If these really are 16 bit wide and 32K deep, they would be great for a SBC I'm building. Especially if the 15 means 15 ns. Any help for pinouts or data sheet greatly appreciated. Billy

19 years, 1 month

8
10
0 0

TTL homebrew CPUs

by dkelvey＠hotmail.com

>From: woodelf <bfranchuk at jetnet.ab.ca> > >dwight elvey wrote: >>Right now, we are at the power density limits for uP's. We can >>build smaller ones and put more circuits on a chip but we've >>hit the limits of power density. We get smaller improvements >>from lower K insulation on wiring but power is now the wall. >>Dwight > >Does this mean that if we reduce the number of transistors >we can go faster? Let see a PDP 8/Z(1) with current technology >would be? :) I think the problem is computer design rather >than the chip design -- You don't have random access memory >any more & salesmen push clock speed rather than a usefull >measure of computing power. > No, it means that you need to be more clever with the transistors that are there. The architectures of today's CPU's are doing several times as much per clock cycle than your PDP8 did. The problem is that they are also running out of tricks in a single CPU. That is why your seeing multi processors becoming more popular. I'm not sure where the future methods will go but they are still holding to Moore's law, just not with increased clock speed as the driving force any more. Dwight _________________________________________________________________ Don't get caught with egg on your face. Play Chicktionary!? http://club.live.com/chicktionary.aspx?icid=chick_hotmailtextlink2

19 years, 1 month

1
0
0 0

Intel uScope 820

by gksloane＠hotmail.com

Did you ever scan the manual for the Intel uScope 820? I have one, and I have the 8080 pod/probe/cable, and the 6K PRO module, but no documentation whatsoever. Whatever you have would be appreciated! If you have a scan of the manual and/or the service manual and can send it to me I'd be very very happy! Gary Sloane SB/US Engineering Inc. _________________________________________________________________ http://newlivehotmail.com

19 years, 1 month

1
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Need Data Sheet

by ajp166＠bellatlantic.net

> >Subject: Re: Need Data Sheet > From: "Ethan Dicks" <ethan.dicks at gmail.com> > Date: Tue, 10 Jul 2007 15:08:19 -0500 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >On 7/9/07, Chuck Guzis <cclist at sydex.com> wrote: >> OTOH, there's a nice 16bit SRAM in some modems, such as the Hayes >> 28.8K external models. In an 0.300" wide DIP too. > >Oooh... that could be fun to play with. I didn't figure that a cache >SRAM was anything other than 4-bits wide (386/486 era) or 8-bits wide >(486/Pentium era), especially since I've used a bog standard cache RAM >on an 1802, but knowing there really are 16-bit-wide SRAMs could be >fun for, say, a 68000-based board, or even throwing away 4 bits and >using it as a 12-bit-wide single part for a PDP-8. > >Any idea what the part number might be for that RAM chip? Vendor? It's a 8bit wide part I have a bag of those and similar parts. FYI they are 15ns and for super fast memory systems as in cache but for fast systems they are the cats meow. > >-ethan

19 years, 1 month

1
0
0 0

TTL homebrew CPUs

by ajp166＠bellatlantic.net

> >Subject: Re: TTL homebrew CPUs > From: woodelf <bfranchuk at jetnet.ab.ca> > Date: Tue, 10 Jul 2007 11:04:27 -0600 > To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> > >dwight elvey wrote: >> Right now, we are at the power density limits for uP's. We can >> build smaller ones and put more circuits on a chip but we've >> hit the limits of power density. We get smaller improvements >> from lower K insulation on wiring but power is now the wall. >> Dwight > >Does this mean that if we reduce the number of transistors >we can go faster? Let see a PDP 8/Z(1) with current technology >would be? :) I think the problem is computer design rather >than the chip design -- You don't have random access memory >any more & salesmen push clock speed rather than a usefull >measure of computing power. > >(1) Zippy - 1000x faster the a PDP 8/E. >Now back to thinking about how to build a homebrew CPU... >Front panel or no Front panel. > The pdp8 limitation back then was not the CPU but the fact that it's timing was interlocked with the core. Take core out of the timing picture with fast Sram and crank it up then things like bus timing and ripple carry are a factor. So a turbo PDP-8 is achieveable and if it were all on a chip your "8/Z" would be scary fast with current tech. However if you reduce the number of transistors as MIPS and other RISC machines early on did your dependent on raw speed at the die level and the cycle repeats. That is you end up pushing for ever higher speeds to make up for simplicity and those transistors left are hitting the speed/power wall. Then of course you can try to push that by making the machine wider. The process does the lather, rinse and repeat with new process slipping in to help out but we are approaching the sub atomic level were transistors perform badly as there are not enough molecules in them! So we go back and add more parallel cpus on the same die and that means more transistors and we go around again. Allison

19 years, 1 month

1
0
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Amstrad PCW 8256 and 3.5 DS2D Drives

by cclist＠sydex.com

I recently picked up an Amstrad 8256 for its floppy drive (Hint: replace the drive belt with a cheap polyurethane "elastiband" type of "rubber" band. It works great.) That left me with a machine that would either hit the recyclers or that I could keep around. When I looked at the basic box--4MHz Z80, graphics, 512K of RAM...I couldn't bear to toss it out without at least playing with it a bit. I installed a Teac FD235F 720K drive in place of the original one and then contemplated what I was going to do for a boot diskette. None came with the machine. Digging through my collection turned up a 3.5" CP/M 3.0 boot diskette for a PCW 9512 (DisKit), but simply trying to boot from it got me nowhere. (Beep Beep Beep). I found that the checksum of the boot sector identified the target boot machine. My sample checksummed to 0x01, where my documentation said that the PCW 8256 required a checksum of 0xff. Decrementing the "fixup byte" at offset 0x0f in the boot sector by 3 from 0xD1 to 0xCF did the trick. The lowly Joyce now boots CP/M. I've not seen this trick documented, so I thought I'd report it here. The easiest thing would have been to change the boot ROM code, but that appears to be buried in a gate array and not a regular EPROM. I note that the PCW uses the RST 7 vector for interrupts, which conflicts with the breakpoint interrupt used by DDT and ZSID. Fortunately, there appears to be a patch for that. While it might be fun to get the PCW to run MP/M II, my interest has waned a bit, so the thing will now go back onto the shelf. Without a regular printer or serial port, an anemic PSU and a horrible keyboard, it's going to be of limited utility anyway--for now. Cheers, Chuck

19 years, 1 month

1
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Pics of my cleaned-up Crimson VGX.

by austin＠ozpass.co.uk

Thanks for all of the recent assistance regarding cleaning products for my Crimson VGX. A combination of Naptha (in Zippo lighter fluid form) and hot soapy water have cleaned it up a treat. In fact it?s now looking almost as good as new, pics here: http://ozpass.co.uk The system almost boots as well. I don?t have a keyboard for it so I?ve made a null-modem cable with USB adapter for my MacBook and hooked it to the VGX using minicom. This redirects the console to the serial port so I can watch it booting. Currently it?s halting whilst trying to mount an NFS share from a computer called ?Onyx?. I guess I?ll have to edit fstab to remove the offending entry. In other good news I?ve discovered an IRIX 5.3 CD in the drive, complete with caddy! It?s days like today with a sparkling clean functional SGI Crimson VGX in your kitchen that the hobby makes perfect sense (except to one?s better half! ;-) -Austin.

19 years, 1 month

2
2
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TTL homebrew CPUs

by ajp166＠bellatlantic.net

> >Subject: Re: TTL homebrew CPUs > From: Dave McGuire <mcguire at neurotica.com> > Date: Mon, 09 Jul 2007 18:45:52 -0400 > To: "General Discussion: On-Topic Posts Only" <cctech at classiccmp.org> > >On Jul 9, 2007, at 5:51 PM, Tony Duell wrote: >>> recycled industry application notes), that required some special >>> circuit >>> only available at their or associated stores. Having seen the nth PIC >>> application that basically blinks a LED - what my generation built >>> with >>> 2 transistors, 2 capacitors, 4 resistors - is lame. >> >> You're making me feel very old. When I was a kid, I used to make a >> neon >> bulb blink using one resistor and one capacitor. > > Relaxation oscillators are fun. I like the UJT version as well, >though UJTs are getting harder to find than they once were. I have >two or three 2N2646 UJTs left. Yes but you can build your own UJT using a 2n3904 and 3906 plus two resistors. Allison > > -Dave > >-- >Dave McGuire >Port Charlotte, FL >

19 years, 1 month

2
1
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Need Data Sheet

by ajp166＠bellatlantic.net

> >Subject: Need Data Sheet > From: "Billy Pettit" <Billy.Pettit at wdc.com> > Date: Mon, 09 Jul 2007 17:15:33 -0700 > To: <cctalk at classiccmp.org> > >I recently came across a stock of what seems to be 16 bit wide memory chips. >But I'm getting nowhere trying to find a data sheet. Can anybody help out? > > > >The parts are UM61M512K-15, 32 pins DIP. The logo is round, world shaped >with 3 vertical and 3 horizontal lines. Date codes are 95 and 96. > > Mine are 64kx8. Did you try google "um61512 datasheet"? Allison

19 years, 1 month

1
0
0 0

TTL homebrew CPUs

by ajp166＠bellatlantic.net

> >Subject: Re: TTL homebrew CPUs > From: woodelf <bfranchuk at jetnet.ab.ca> > Date: Mon, 09 Jul 2007 23:23:00 -0600 > To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> > >dwight elvey wrote: > >> If you really want them to act like a TD, place a resistor in parallel >> to give the final slope. It doesn't make them any better at doing >> fun things but is closer the a real TD. >> Dwight >But with a ka-zillion tunnel diodes you can build the fastest >computer ever. Well that was what all the hype was about in the >early 60's. >Did anyone ever use Junction Fets in computer logic? Not that I've seen. Likely reason for that is by time the JFETs became common enough production computers were IC based. However MOSfets on silicon did make it into IC as CMOS and well.. there in computers big time, Allison

19 years, 1 month

1
0
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TTL homebrew CPUs

by Billy.Pettit＠wdc.com

Tony Duell wrote: I do? That's news to me. I am not sure there _was_ Elektor in the UK in 1974... The early UK computer projects I know about are : the 'PE Champ' (that's tue UK magazine 'Practical Electronics') from 1977 (a 4040-based computer + 1702 programmer + UV eraser) ; the PE Digi-Cal from 1972 (a 4-function dsektop calculator built in TTL + a diode-matrix ROM. I don't recall any general-purpose computer built from TTL in a UK magazine. [ snip ] -tony I believe that Elektor was publishing in the UK in 1974, but I don't have my copies at hand to pick the exact date. I know the first and second binders were full by the end of 1976 (I used to buy the publisher's binders, an icky green, tacky board binder). And I read all of them but do not remember any computer projects. And I would have been extremely interested because I was building an 8 bit TTL machine at the time. However, there was the ACS (Amateur Computer Society), an early UK computer group that designed and built a 16 bit TTL computer. It was well documented in their Newsletter in the mid-70's. All my copies were stolen, and I've looked for 20 years to find copies. Any chance of the UK CC'ers having copies of these newsletters? Billy

19 years, 1 month

1
0
0 0

S-100

by RodSmallwood＠mail.ediconsulting.co.uk

Thanks.. I did ... Rod -----Original Message----- From: cctech-bounces at classiccmp.org [mailto:cctech-bounces at classiccmp.org] On Behalf Of Andrew Lynch Sent: 09 July 2007 22:00 To: cctech at classiccmp.org; RodSmallwood at obmr.btconnect.com Subject: Re: S-100 Hi Does anybody have: a) A Northstar Horizon S100 Mother board (Need not be working or populated) b) The PCB artwork for the above. c) Any other S-100 mother board. d) The PCB artwork for the above. Anything more would be a bit expensive on shipping from the US. So its just the board that's required Rod Smallwood Hi Rod, Check out http://groups.yahoo.com/group/Verns_Stuff/ Vern has a NorthStar Horizon chassis with motherboard for sale. I'd bet he would sell you the motherboard alone if you made an offer. Tell Vern I sent you and you saw this on CCTALK mailing list. Thanks! Andrew Lynch

19 years, 1 month

1
0
0 0

S-100

by lynchaj＠yahoo.com

Hi Does anybody have: a) A Northstar Horizon S100 Mother board (Need not be working or populated) b) The PCB artwork for the above. c) Any other S-100 mother board. d) The PCB artwork for the above. Anything more would be a bit expensive on shipping >from the US. So its just the board that's required Rod Smallwood Hi Rod, Check out http://groups.yahoo.com/group/Verns_Stuff/ Vern has a NorthStar Horizon chassis with motherboard for sale. I'd bet he would sell you the motherboard alone if you made an offer. Tell Vern I sent you and you saw this on CCTALK mailing list. Thanks! Andrew Lynch

19 years, 1 month

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Antique computer books for sale

by janprunk＠gmail.com

Hello ! I received some antique books about computing from the library. They are all in English language and in good condition. The price for one book is 3 Euros + postage. The books are shipped >from Slovenia, Europe. The link to the list is available at: http://yang.mtveurope.org/books.html If you are interested, contact me to my private email address. Kind regards, Jan Prunk -- +------------------------------------------------------------------+ | Jan Prunk GPG key: 00E80E86 | | E-mail: jan at prunk.be Fingerprint: 77C5 156E 29A4 EB6C 1C4A | | http://blog.prunk.be 5EBA 414A 29F5 00E8 0E86 | +------------------------------------------------------------------+

19 years, 1 month

1
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Trace Wrinkles

by marvin＠west.net

> From: "Mike Hatch" <mike at brickfieldspark.org> > > I haven't heard anyone discuss this yet: what causes traces on some old > > PCBs to wrinkle and not others? My guess is a combination of suboptimal > > glue and wide temperature swings. > > > Caused by the hot air solder levelling process when a manufacturer skips a > process or has the process order slightly out. > The solder should only be deposited on the component pads, but some > manufacturers used to put the solder on before the silk screen, then level > the board. The solder melts during levelling and aggregates under the mask > forming the "wrinkles". > > It should be - silk screen, apply tin/lead to pads, level. > It can be - tin/lead, silk screen, mask, level. > but if its - apply tin/lead, silk screen, level - you get wrinkles. You seem to be implying that the wrinkles are a result of the PCB manufacturing process, and that is wrong; the wrinkles you are talking about occur during wave soldering at the assembly portion of the process. By going to SMOBC (Solder Mask Over Bare Copper), both the wrinkles and extra weight of solder picked up during the wave soldering process were eliminated. And of course, it was not a problem when the boards were hand soldered. The wrinkles are NOT caused by hot air leveling (that was my area of expertise when I was working as a field engineer installing/training/maintaining Gyrex Hot Air Levelers.) I know of no process or reason for putting soldermask over tin/lead and using Hot Air Leveling for the reflow process. Hot air leveling was mainly used for SMOBC boards. Solder gives a longer shelf life than the SealBrite coatings that were also fairly common a number of years ago, and thus Hot Air Leveling was also used on some boards without soldermask. The usual manufacturing process before hot air leveling was drill, electroless copper/copper plate, plating resist applied (either photographically or silkscreening), copper plate to desired thickness, tin/lead plate, strip resist, and etch. If the board was going to be hot air leveled, the tin/lead plating was chemically removed. Otherwise it went through a reflow process to alloy the tin/lead into solder before the soldermask was applied.

19 years, 1 month

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Strange SCSI devices (was: Re: LISA)

by Arno_1983＠gmx.de

Ray Arachelian <ray at arachelian.com> wrote: > As as aside, there were lots of very strange things on SCSI busses back > in the day. Scanners were quite common, but there actually existed > printers, and even video cards on SCSI busses. :-) The SCSI video card > and ethernet card were useful for compact Macs that had a scsi port, but > no expansion slots. Not even to speak of some of the stuff the scientific camp came to use. I got two "Gradient DeskLAB" SCSI DSP boxen for audio I/O from a chair at University where they were used for speech recognition and synthesis in the context of an automatic phone-in train timetable information system. Unfortunately absolutely no documentation and/or software to go with them, not much about them in the web (except for some people stating they used them for diploma thesis and similar), so I'm looking for any information about them you could come up with. -- Arno Kletzander Studentische Hilfskraft Informatik Sammlung Erlangen www.iser.uni-erlangen.de Ist Ihr Browser Vista-kompatibel? Jetzt die neuesten Browser-Versionen downloaden: http://www.gmx.net/de/go/browser

19 years, 1 month

7
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M9312 boot rom trade

by wacarder＠earthlink.net

I spent a little time yesterday going through my M9312 boot roms. I have a few spares for devices that I do not have, and I am looking for a few boot roms for devices that I do have. If anyone wants to trade or if you have the boot roms I need, contact me offlist at wacarder at usit.net. Spare ROMs that I have: 755A9 - RP02/03/04/05/06 RM02/03 757A9 - TU16 TE16 TM02/03 I am looking for these: 753A9 - RX01 811A9 - RX02 756A9 - RK05 760A9 - PC05 761A9 - TU60 758A9 - TU10 One other note: I found a few 'oddball' boot ROMs. By examining the contents of the ROMs, I determined that the mnemonics for them are DA and DN. Does anyone know what devices these are for? They are not listed in the M9312 technical reference. Thanks, Ashley Carder http://www.woffordwitch.com

19 years, 1 month

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[lisaem] LisaEm 1.0.0 Released

by ray＠arachelian.com

LisaEm 1.0.0 has been released. Download is available at http://lisaem.sunder.net/downloads.html as usual. ------------------------------------------------------------------------------ Lisa Emulator Change History http://lisaem.sunder.net/ ------------------------------------------------------------------------------ 2007.07.06 - Display color balancing to remove fuzziness. 2007.07.05 - LisaConfig bugs found - overwriting date information with garbage on save of preferences. - corrected a bug preventing the grabbing of the host time and date. Found that MacWorks locks up when date is invalid. 2007.07.04 - LisaEm documentation completion 2007.07.03 - Testing various opcodes to locate scroll bar arrow bug in LOS not found, but eliminated shift/rotate opcodes. 2007.07.01 - regression testing to locate MacWorks bug - not found yet, high probability that it lives somewhere inside the C++ code. 2007.06.30 - added Mac OS trap symbol printing for A-Line traps for tracelog 2007.06.29 - fixed inability to detect no-floppy from Lisa boot ROM - fixed entry to Service mode - not perfect, need to attempt to boot from bad profile. - fixed tracelog bugs (hardcoded /log/lisaem-output)

19 years, 1 month

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Altair Kits

by gstreet＠indy.net

Hello All, Regarding the Altair 8800 repro kit: An unsolicited plug -- This kit is of the highest quality. Because of my ridiculous commute schedules, I can only work on my kit sporatically. I missed my big chance to build one in 1975, and I when I saw this kit, I vowed not to miss it again. It's been a long time coming, but it was worth the wait. I love this kit!!! Kudos to Grant! Regards, Robert Greenstreet

19 years, 1 month

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Old Modems and Telephony switches

by Peter.Coghlan＠EUROKOM.IE

> >I've got a lead on some four-wire and X.25 ("frame relay"?) stuff from University and just yesterday I got my second ADSL modem. What would it take to set up or "simulate" their counterpart (DSLAM?) at home? > Hi Arno, I've got some X.25 equipment which needs a good home. I have two Satelcom switches, two Dec DEMSB routers and two 4-wire NTUs ("baseband modems?") plus a few cables and manuals. The switches power up and can be configured from a console terminal but have problems retaining their configuration over a power off. This is probably due to a problem with the internal PCB mounted batteries which I have had to replace previously. One of them has a push-on connector from the power supply replaced by a soldered connection where the connector had overheated. The NTUs also power up and appear to work. I haven't tried the DEMSBs. Normally the NTUs are clocked from the telephone exchange end but it is possible to change the links in one to get it to generate a clock internally so that the two can talk to each other over a 4 wire crossover cable. At least, I can get all the LEDS to illuminate. I don't know enough about X.25 etc to get any further than that. Let me know if you are interested. However, I am located in Dublin, Ireland so I am not sure how it would be possible to get the stuff to you if you do want it. Regards, Peter Coghlan.

19 years, 1 month

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cctalk Digest, Vol 47, Issue 12, Message 3 - Trace wrinkles

by mike＠brickfieldspark.org

> Message: 3 > Date: Fri, 6 Jul 2007 11:39:56 -0700 (PDT) > From: David Griffith <dgriffi at cs.csubak.edu> > Subject: trace wrinkles > > I haven't heard anyone discuss this yet: what causes traces on some old > PCBs to wrinkle and not others? My guess is a combination of suboptimal > glue and wide temperature swings. > Caused by the hot air solder levelling process when a manufacturer skips a process or has the process order slightly out. The solder should only be deposited on the component pads, but some manufacturers used to put the solder on before the silk screen, then level the board. The solder melts during levelling and aggregates under the mask forming the "wrinkles". It should be - silk screen, apply tin/lead to pads, level. It can be - tin/lead, silk screen, mask, level. but if its - apply tin/lead, silk screen, level - you get wrinkles. Wrinkles became less prevalent as tin/lead material costs went up, does not happen now as tin/lead here (UK) is banned except for special applications.

19 years, 1 month

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trace wrinkles

by n8uhn＠yahoo.com

Hi All, i find it interesting that no one has mentioned the peel and press method of pcb making. some boards are not etched and placed in a chemical bath. instead the board starts as a copperless plate and the traces are on a sheet that carries the traces like a rub on transfer. the sheet has a protective layer that is removed and then the sheet is lay'ed on the blank pcb and pressed or rolled or vacuum pressure is applied. then the holes are drilled. after years of exposure to heat and air or even a bad transfer to start with, the traces "bubble" and wrinkle. i have not seen too many computer boards or cards made this way but alot of consumer audio and cb or marine two way radio's are made with this style of pcb and are a real pain to repair. when the trace is heated to replace a bad component, it wants to lift very quickly. my guess is that the peel and press way is cheaper then a real etched board. Bill ____________________________________________________________________________________Ready for the edge of your seat? Check out tonight's top picks on Yahoo! TV. http://tv.yahoo.com/

19 years, 1 month

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TTL homebrew CPUs

by ed＠ed-thelen.org

Wakkkyness is not dead. "The Madscientist Builds a Processor" http://madscientistroom.org/table/mippy/ is the tale of a *second* electronics project, the first was a one chip TTL counter. Randy thought that was not hard, why not try a computer? He learned: - add lotsa capacitors between +5v and gnd, all over - ground can jump up and bite ya (a ground plane is a good thing) - and a lot of other practical stuff but crashed on, and finally succeeded :-))) Ed "Pops" Thelen

19 years, 1 month

1
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TTL homebrew CPUs

by ajp166＠bellatlantic.net

> >Subject: Re: TTL homebrew CPUs > From: woodelf <bfranchuk at jetnet.ab.ca> > Date: Sun, 08 Jul 2007 16:06:02 -0600 > To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> > >Allison wrote: > >> If I were to do a TTL design right now I'd use 32Kx8 >> (or larger) parts even if the word size were 9 or 11 bits >> as they are cheap and easy to use and the unused excess bits >> are no real loss. >11 Bits ??? What uses that? Nothing I know of but theres no reason in the world to say that could not be done. >> Maybe because every time I did TTL or slice design I wasn't >> trying to make a period machine or be faithful I was doing >> some sacrelige but I was having fun and the expereince was >> no less because the memory, logic used or terminal was >> way out of period. > >If this your hobby , the main thing is to have fun. Roger that! ;) > >> Heck the guy that did the Apollo AGC has a hats off to me as >> he did in TTL something conceived as RTL with minimal data. >> If anything not only was a working machine a significant >> accomplishment but the information about it he dug up, made >> visible to public and preserved along the way speaks to >> great work. > >That was great work. I admire just finding all the data. That was a easter egg hunt if there ever was one. >> >> For those that try and or succeed to build a PISC >> (Pitiful Instruction Set Computer) or a VSC (Very >> Simple Computer) they are contributing a lot to the >> science and history of computing. After all there >> are many old (really old) machine preserved and sitting >> that most of us have not the first idea how to power >> up and program. Those that do it get my attention for >> their efforts. > >The Kenback 1 and the 6800 replica's that come >up is great work too. I wish I could get him >to do my cpu from my hen scratched schematics. >Now the biggest problem I have is do I want >Single Instruction or not with my minimal front >panel? Is that used that often that it needed? >Ben alias woolelf I have only done one front pannel, it was as much or more work than the CPU. It's all the wires and as I like to call it "drillin and blastin". So generally I try to avoid that or do a very minimal one for debug rather than show. The choice of what to build is always tough as there are so many choices. In the end I started with very simple state machines and microprogrammed controllers and gradually decided what capability was missing and how best to achieve it based on what I knew and had done. Whats funny is it's easier to design a slower wide word (32 or more bits) machine (lots of the same stuff repeated) than faster narrow word (8bit) machine. Then you get into variable word length or fixed, single address or multiple, register or memory based, microcode or random logic control, CISC or RISC. In the end whatever is built you're not going to be condemmed as at least it was built. >PS. How are IRQ's handeled when single stepping? Slowly. ;) Single stepping would just mean if there was an INT pending you would see all the steps and the adress changes involved. Or as I was told once, "Your the engineer, what do you want it to do?". Allison > > >

19 years, 1 month

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S-100

by RodSmallwood＠mail.ediconsulting.co.uk

Hi Does anybody have: a) A Northstar Horizon S100 Mother board (Need not be working or populated) b) The PCB artwork for the above. c) Any other S-100 mother board. d) The PCB artwork for the above. Anything more would be a bit expensive on shipping from the US. So its just the board that's required Rod Smallwood

19 years, 1 month

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Altair 680 Replica Kit available

by grant＠stockly.com

Well, another labor of "love" for the past 6 months is finally done. Please take a look at http://www.altair680kit.com/index.html I'd love to hear any questions/feedback on the subject. Thanks, Grant

19 years, 1 month

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Telephony switches - is there anyone out there collecting these?

by jplist2007＠kiwigeek.com

Hey all; So I'm reading "The NEW McGraw-Hill TELECOM Factbook" (Second edition, "A plain English guide anyone can use!", 820 pages, phone book sized) and while delving into the sections on Circuit and Packet switching it occurs to me that these machines are just as much of an object that has enabled our industrial and technological revolution to continue in leaps and bounds as the minis and mainframes of yesteryear. They're also damned cool. Are there people out there, on the list or otherwise, that are actively collecting these machines? Admittedly, unlike a PDP8 you can use (as Dave McGuire does) on a daily basis, a twelve ton NEAX isn't too 'dramatic' as an attention piece. But, according to my little book here, they tend to be multiprocessor, reel-to-reel storage (as they 'reboot' so infrequently they need a very long-lasting storage medium), all sorts of good stuff. And with an average "Mean time between failure of 1 failure in 40 years"... boy, that just speaks for it. So, anyone out there have one of these in their... basement? JP

19 years, 1 month

21
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Northstar hard sector floppy disks with Catweasel

by lynchaj＠yahoo.com

Hi, Has anyone had success reading Northstar hard sector floppy disks with the Catweasel? Thanks! Andrew Lynch

19 years, 1 month

2
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TTL homebrew CPUs

by ajp166＠bellatlantic.net

> >Subject: Re: TTL homebrew CPUs > From: woodelf <bfranchuk at jetnet.ab.ca> > Date: Sun, 08 Jul 2007 14:12:15 -0600 > To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> > >Allison wrote: >> >> >> There is a lot of "you can do" but building a CPU comes down to what do >> you want to do and can reasonably achieve or can practically play with >> once functional. Unfortunately some want a cpu that can run unix and an >> IP stack others want just enough to qualify as a computer for close up >> examination of "just how do they do it?" and that represents a large >> spread of design and architecture possibilities. Having built machine >> from very simple state logic to an elaborate 16bit bitslice I can say >> all are interesting but some are a lot too much work. > >Memory is a interesting problem , if you don't use 8 bit bytes >or you need more than 32K. Since I had use of computers after >1980 64Kb or more seems normal. I am shocked >at how hard it is get any memory size at all using static >memory with the 75 to 80's chips and still not use >up mammonth amounts of power or large # or boards. Why the surprize? Until the 4k dynamic parts 1k was huge and the older dynamic parts require a lot of support (read TTL bits). That lack of density says power is big by shear force of numbers. I had the use of computers before the 70s (ok only 1969) but I got to see the growth. It was interesting to see 4K of core shrink from a box to a board and further to a chip. Myself I used in the past the higest density parts memory wise I could to save power and wiring. The 2102, 2114 2167 type static parts made life far easier than the 4116 dynamics. But by 1978 it was possible to put 64kx8 on a S100 card cheaply (by then standard) using 16kx1(4116) and 8202. If I were to do a TTL design right now I'd use 32Kx8 (or larger) parts even if the word size were 9 or 11 bits as they are cheap and easy to use and the unused excess bits are no real loss. I'm currently looking at using 64Kx8s as a way to make a RS08like disk for my PDP-8f. So what if I don't use 4 of the 16bits the cost to find X4 parts or other schemes end up using more parts or time. Maybe because every time I did TTL or slice design I wasn't trying to make a period machine or be faithful I was doing some sacrelige but I was having fun and the expereince was no less because the memory, logic used or terminal was way out of period. Heck the guy that did the Apollo AGC has a hats off to me as he did in TTL something conceived as RTL with minimal data. If anything not only was a working machine a significant accomplishment but the information about it he dug up, made visible to public and preserved along the way speaks to great work. For those that try and or succeed to build a PISC (Pitiful Instruction Set Computer) or a VSC (Very Simple Computer) they are contributing a lot to the science and history of computing. After all there are many old (really old) machine preserved and sitting that most of us have not the first idea how to power up and program. Those that do it get my attention for their efforts. Allison > > >

19 years, 1 month

2
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The late, great TRS-80 - hey, they wrote a book!

by ajp166＠bellatlantic.net

> >Subject: Re: The late, great TRS-80 - hey, they wrote a book! > From: Fred Cisin <cisin at xenosoft.com> > Date: Sat, 07 Jul 2007 16:05:20 -0700 (PDT) > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >On Sat, 7 Jul 2007 scheefj at netscape.net wrote: > >How do you spell shill? > >Lighten up on the hard sell. > >> All, >> I cannot believe that after two weeks and about 40 messages, no one >> actually responded to Theresa's actual message. Instead, from the first >> "reply" you all were off arguing inane stuff like whether English >> measure units are better than something else. You idiots! </flame> >> If you doubt that the TRS-80 Model 1 was, as Theresa claimed in her >> original message, the "first off-the-shelf home computer", then I >> respectfully suggest that you READ THE BOOK! > >I was going to buy a copy of that book to add to the circulation >collection. Your flame resulted in deleting it from the acquisition list. > > >We were there. > >The responses were NOT about "English measure units". They were extensive >(and sometimes silly) disagreements about how "first", "Off-the-shelf", >and "home computer" were defined. It takes some very creative definitions >to be able to assign that honor to TRS80. >Theresa's definitions were barely defensible! > >Some of us, (Allison, etc.) were responsible for major design decisions. > >Some of us remember more detail than was found by the authors of >"interview" books. Such as the time when RS said that they would be >marketing an S100 adapter. Or the bad connections with the serial board. >Or the multiple iterations of patches on top of kludges trying to get the >CPU to E.I. cabling to work reliably. Or (mostly Coco) when RS declared >that because "RS232" stood for "Radio Shack 232", that it was thus open to >changes at the whim of RS. > >Some of us are tired of "history" with a "light style" (no technical >details and/or no attempt to proof technical aspects) > >Some of us are tired of undefined and ill-defined disputable "firsts". > > >-- >Grumpy Ol' Fred cisin at xenosoft.com Right on Fred. Besides the first off the shelf is more like the CDC160 or PDP-8. For that fact AppleII was even before the TRS80. There were several fully assembled machines that predate the TRS80 some were even more capable. Frist what? First home computer for under $1000? First sold through a major chain? The late 60s through yesterday have been full of first in some area or another when we talk about computers. As for me when I'd first seen the title I hit delete as the TRS80 was an interesing and common oddity. It succeeded (that is it sold many) despite design flaws, outright bugs, and production teething pains. If anything I'd conclude little about the TRS80 and more about how hungry the market was for a computing solution that could be applied as an appliance or tool rather than technotoy. The real story if one is to be less technical is how the market progressed from PDP-8 to the Mark8 and beyond MITS to the more finished machines that could do basic accounting, write and print a letter or play a decent game. Computing and the machine makers tried to answer the buring question of what does the computer consumer want or need to be a useful tool they would buy? >From that perspective what MITS, APPLE or RS (and many others) did on their own has less significance than the combined effect of getting computers from behind plate glass and in front fo the guy that ways to know how many things to stock for the next big sale weekend. KO was right, people didn't want computers, they wanted infomation appliances. All the so called firsts were only steps to that end. The end remarkably is the same as when the Gutenberg Bible was first printed, rapid ready access to information, with information being THE commodity. Just my two cents, but hey what do I know. Allison

19 years, 1 month

2
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Turn a disk into the starship Enterprise!

by aliensrcooluk＠yahoo.co.uk

Hi, Someone came across this in another group I am in. http://www.asciipr0n.com/archive/0013/bonnie/craft/ It's pretty cool, but I wouldn't use any old disks for this, just crappy PC ones (from modern PC's) which no longer work :) Regards, Andrew B aliensrcooluk at yahoo.co.uk

19 years, 1 month

1
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TTL homebrew CPUs

by ajp166＠bellatlantic.net

> >Subject: Re: TTL homebrew CPUs > From: "Roy J. Tellason" <rtellason at verizon.net> > Date: Sun, 08 Jul 2007 14:46:09 -0400 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >I can recall a couple of different articles on boards that were designed to >plug into a PC, one used a 32032, one a 68K of some sort, and one a Z8000, >I think. I didn't pay them that much attention because I didn't have a "PC" >yet, at that point in time. :-) I may have those articles as well. I also suffered from not having a PC but the designs were very generic if you ignore the PC part and therefore handy. Allison

19 years, 1 month

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TTL homebrew CPUs

by ajp166＠bellatlantic.net

> >Subject: Re: TTL homebrew CPUs > From: Lars Hamren <hamren at sdu.se> > Date: Sat, 07 Jul 2007 21:38:15 +0200 > To: cctalk at classiccmp.org > >The first computer built by Computer Automation, circa 1967, was the >PDC 808. It was an 8-bit TTL-only machine with a very basic >instruction set. In "Computer Technician's Handbook" Brice Ward >describes tat machine in great detail. Should be enough to build a >replica from. > >A scanned version of the relevant parts of that book is available from > > http://www.sdu.se/computer-automation-museum/books_in_the_collection.html > >PDC stands for Programmable Digital Controller. The word "computer" >was avoided because people were afraid of them! > >The "8" means 8 uS cycle time, and "08" means 8 bits. The 208 was >three times as fast (2.66 uS cycle time, hence the "2"). > >/Lars I've seen a lot of discussion on making a CPU from TTL or MSI (bitslice). The task is not that bad and the parts to do it are very available still. The assembly task with out a premade board can be large as it's a lot of repetive circuits. If the word size is kept reasonable but useful and that seems to be 8 to 16 bits people are doing it. The variable word length 8bit designs are scarce but requires less bus "width" to get a workable system and have performance in the zone of faster than serial but not as fast as wide word machines. Using that approach you can have a 32bit machine with 8bit busses saving a huge amount of repetetive hardware. For those that want small and less significant part counts there are minimalist 8/12/16 designs like TOY or Pilgrim VSC (very simple computers). A board for one of them would have wide appeal and useful for those that wish to see the guts of cpu without probling a die or having a whole PDP-8. The biggest difference between building a PDP-8 (or whatever) then and now is not using TTL (or cmos) or bit slices but the availability of fast and large RAM that is easy to use. Many earlier systems were flavored by the ram they could interface or the needs of the memory. Same for the older serial designs to were done to economize on then costly registers and arithmetic logic along with serial memories. There is a lot of "you can do" but building a CPU comes down to what do you want to do and can reasonably achieve or can practically play with once functional. Unfortunately some want a cpu that can run unix and an IP stack others want just enough to qualify as a computer for close up examination of "just how do they do it?" and that represents a large spread of design and architecture possibilities. Having built machine >from very simple state logic to an elaborate 16bit bitslice I can say all are interesting but some are a lot too much work. Allison

19 years, 1 month

2
1
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Diablo Hyterm near Eugene, OR

by cclist＠sydex.com

http://eugene.craigslist.org/zip/368914556.html

19 years, 1 month

1
0
0 0

TTL homebrew CPUs

by hamren＠sdu.se

The first computer built by Computer Automation, circa 1967, was the PDC 808. It was an 8-bit TTL-only machine with a very basic instruction set. In "Computer Technician's Handbook" Brice Ward describes tat machine in great detail. Should be enough to build a replica from. A scanned version of the relevant parts of that book is available from http://www.sdu.se/computer-automation-museum/books_in_the_collection.html PDC stands for Programmable Digital Controller. The word "computer" was avoided because people were afraid of them! The "8" means 8 uS cycle time, and "08" means 8 bits. The 208 was three times as fast (2.66 uS cycle time, hence the "2"). /Lars ------------------------------------------------------------------- Lars Hamr?n Tel...: +46( 46)189090 Svensk Datorutveckling Mobile: +46(705)189090 Vadm?llan 211 e-mail: hamren at sdu.se S-225 94 Lund WWW...: www.sdu.se Sweden

19 years, 1 month

7
7
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Northstar hard sector floppy disks with Catweasel

by ajp166＠bellatlantic.net

> >Subject: Northstar hard sector floppy disks with Catweasel > From: "Andrew Lynch" <lynchaj at yahoo.com> > Date: Sun, 08 Jul 2007 12:10:35 -0400 > To: <cctech at classiccmp.org> > >Hi, > >Has anyone had success reading Northstar hard sector floppy disks with the >Catweasel? I keep hearing about this Catweasel board and I've never read of anyone successfully using one. My be if it works there may be nothing to tell. NS* floppies are a simple affair. The logic needed to read them is trivial and the data rate is 15625(SD) or 31250(DD) bytes/second. The NS* board logic is clock recovery, shift register and a 8wide NAND to detect if the pattern in register is a sync byte. The basic read is, wait for sector hole (hard sector has both an index hole and a data sector hole and a oneshot is used to tell which is which. Once the desired sector hole is found wait for sync (FBh). When sync is found read bytes as they are data(256 sd or 512 dd) the next byte is a check char if the check matches data in ram check byte you have a sector. There are no bytes for sector address or other info as hard sectoring us used to track that. In 8080 code ignoring the head step and all the other housekeeping the read sector code is less than 50 bytes. You can find that code on the net (NS* BOOT ROM). Because of it's simplicity I'm surprized no one has implemented a PC parallel port interface that is a subset of the NS* MDS sans boot roms and bus interface as the data rates are not out of the realm of what a 386 class or faster PC can transfer from a printer port. Manual and prints for the S100 card are available on line and the manual has low level programming information as well. There are no mysteries either hardware or software and the design is dirt simple. Actual parts count for the MDS=A (SD version ) is 47 peices TTL and if you take out boot proms (2 256x4 74287) and board select prom (1 256x4 74287) and the parts needed to talk to the S100 bus your under 40pieces of TTL the most complex of which is 74161 (4 bit counter). I'd add the SD version does not have any analog (opamps) or RC oneshots though the DD version does. the basic timing of the board is a long string of counters synced to the index hole to provide sector position (R/W) and byte timing for (W) and motor time out. No state machines or anything fancy. Allison > > > >Thanks! > >Andrew Lynch

19 years, 1 month

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TTL homebrew CPUs

by ajp166＠bellatlantic.net

> >Subject: Re: TTL homebrew CPUs > From: woodelf <bfranchuk at jetnet.ab.ca> > Date: Sat, 07 Jul 2007 19:58:10 -0600 > To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> > >Dave McGuire wrote: >> >> Ahh, back in the days in which BYTE was a technical magazine. Do you >> have any recollection of when that article was printed? I'd love to >> find it. > >So would I. I suspect 90% of BYTE magizines from local ( ie small) >libraries have been tossed out. It has been tossed out here. >I am not sure if the 32 bit machine >even made it microfilm copies of byte. But I do know it was some time >after BYTE became a PC mag. It was in two parts - part 1 software? >part 2 hardware. > September and October 1985, it was 16bit. EGO 1 wa s it's name. I ahve both copies and a few others regarding TOY a 16bit minimal computer for teaching. I believe issues of byte made it to microfilm and possibly even to compendiums on CDrom. Allison

19 years, 1 month

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TTL homebrew CPUs

by ajp166＠bellatlantic.net

> >Subject: Re: TTL homebrew CPUs > From: "Chuck Guzis" <cclist at sydex.com> > Date: Sat, 07 Jul 2007 13:16:48 -0700 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >On 7 Jul 2007 at 21:38, Lars Hamren wrote: > >> The first computer built by Computer Automation, circa 1967, was the >> PDC 808. It was an 8-bit TTL-only machine with a very basic >> instruction set. In "Computer Technician's Handbook" Brice Ward >> describes tat machine in great detail. Should be enough to build a >> replica from. > >Wasn't there an article in one of the magazines (Byte, >Microcomputing, Kilobaud???) where a fellow gave details about >constructing his own TTL 8080 CPU? Check Mick and Brick on Bit slice design and implmentation of an 8080 in bitslice. Actually 8080 is easier if you are not trying to create a peice of hardware that results in a 40pin plug to replace an 8080. By that I mean something that would run 8080 programs but not electrically compatable and may be slightly different timing. There was also a 16bit CPU in Byte, plus there were articles on TOY (minimalst machine) and further articles on microprogrammed vs hard wired logic. The 16 bitter was EGO in the September 1985 issue (part 1, Part2 is October '85). So there is another fairly simple machine of very buildable proportions with a better than most instruction set. Allison > >Cheers, >Chuck

19 years, 1 month

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Multiple Servers & spares in WA (Kent), FREE to non-profit org!

by kyrrin＠bluefeathertech.com

Classiccmp folk, Time to "flow through" more of my older gear! I have available three Compaq Proliant series servers of various models and speeds, none slower than 400MHz. These were all retired from my network, so I know they're functional. They've simply been replaced by upgraded systems. They all still have RAM (none less than 512MB), and I also have some spare power supplies. I may even be able to scare up enough four-gig disks to make an array. THE KICKERS... LOCAL PICKUP ONLY -- SHIPPING IS NOT AVAILABLE! I simply do not have the facilities or time to ship equipment of this nature. Pickup location is in Kent, Washington, southeast of Seattle. You may reach me at (253) 639-2996. I will donate all three servers, plus spares, FREE to any 501(c)(3) non-profit, or similar organization that can give me a tax-deduction receipt. Failing that, I think $50 per unit is a fair price. Again, I must emphasize -- LOCAL PICKUP ONLY! Shipping is NOT available for this equipment. No, I will not "part them out." These are usable systems, and I want to keep them that way. Thanks much. -=-=-=-=-=-=-=-=-=-=-=- Bruce Lane, Owner & Head Hardware Heavy, Blue Feather Technologies -- http://www.bluefeathertech.com kyrrin (at) bluefeathertech do/t c=o=m "If Salvador Dali had owned a computer, would it have been equipped with surreal ports?"

19 years, 1 month

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DEC Boot ROMs claimed

by kyrrin＠bluefeathertech.com

The boot ROMs have been claimed. My thanks to James Markevitch, and to the list members. -=-=-=-=-=-=-=-=-=-=-=- Bruce Lane, Owner & Head Hardware Heavy, Blue Feather Technologies -- http://www.bluefeathertech.com kyrrin (at) bluefeathertech do/t c=o=m "If Salvador Dali had owned a computer, would it have been equipped with surreal ports?"

19 years, 1 month

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Available for Postage: DEC Boot ROMs

by kyrrin＠bluefeathertech.com

CCTech folk, I have available, for the cost of postage, a pair of DEC boot ROMs used with the M9312. They are the 23-755A9 and 758A9 devices. Additional notations I got with them indicate that they were used with Spectra Logic controllers. The 755 is, apparently, for booting DPn or DBn disks, while the 758 is for booting MTn devices. First respondent gets 'em. Thanks much. -=-=-=-=-=-=-=-=-=-=-=- Bruce Lane, Owner & Head Hardware Heavy, Blue Feather Technologies -- http://www.bluefeathertech.com kyrrin (at) bluefeathertech do/t c=o=m "If Salvador Dali had owned a computer, would it have been equipped with surreal ports?"

19 years, 1 month

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trace wrinkles

by marvin＠west.net

"Wrinkles" is a rather vague description :). When using soldermask and wave soldering the board, the soldermask itself will wrinkle and I would guess all of us who have worked on boards have seen that one. Since a large board can pick up a fair amount of solder during wave soldering (depending on geometry), this adds useless cost to the assembly of PCBs. That problem was eliminated by going to soldermask over bare copper. The second cause of "wrinkles" (and this is probably what you are referring to) is due to the cooling characteristics of the solder after reflow, and this is usually far more prominent on larger circuit areas. I would not classify these as wrinkles per se, but rather the visual boundries where the solder started to solidify on different parts of the circuit. > From: David Griffith <dgriffi at cs.csubak.edu> > > I haven't heard anyone discuss this yet: what causes traces on some old > PCBs to wrinkle and not others? My guess is a combination of suboptimal > glue and wide temperature swings.

19 years, 1 month

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7 RK07 packs in UK

by rescue＠hawkmountain.net

Saw these while searching eBay for other things and thought I'd pass this along in case anyone is looking for RK07 packs... http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=120133419517 I have no knowledge of the seller (or even RK07s :-) )... -- Curt

19 years, 1 month

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Server hosting on a budget - use legacy kit

by lproven＠gmail.com

http://www.channelregister.co.uk/2007/07/07/ebuyer_runs_site_on_commodore64/ I /like/ this. There's a site admin with a sense of humour there somewhere... -- Liam Proven ? Blog, homepage &c: http://lproven.livejournal.com/profile Email: lproven at cix.co.uk ? GMail/GoogleTalk/Orkut: lproven at gmail.com Tel: +44 20-8685-0498 ? Cell: +44 7939-087884 ? Fax: + 44 870-9151419 AOL/AIM/iChat: liamproven at aol.com ? MSN/Messenger: lproven at hotmail.com Yahoo: liamproven at yahoo.co.uk ? Skype: liamproven ? ICQ: 73187508

19 years, 1 month

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Offer: 6' Rack cabinet

by silent700＠gmail.com

A recent basement re-arrange has left me with no room for a rack cabinet I wasn't using that much anyway. I hate to get rid of it, because I'll want one again someday, but for now it's got to go. It's beige/brown color, unknown manufacturer. About 6' high with sides but no front or back doors. It does *not* have the standard front-mounting 19" screw rails except for a movable section of about 18" which bolts into side-facing rails. I think these adapters can be purchased online. What it does have is 9 sets (2 aluminum, the rest heavy steel) of "L" brackets that run the depth of the rack and mount anywhere on the inward-facing screw holes. The steel ones are very strong and could hold a rackmount server, 9-track drive or other heavy items. The rack is large but pretty light; I moved it down to the basement myself. It has no wheels but I've built a wheel-dolly for it. I'm asking $150 for it, or trade for something cool (and smaller!) I was going to put it on ebay as pickup-only, but thought I'd offer it here first. Obviously it would be for pick-up (Palatine, IL, NW of Chicago) only here as well. -j

19 years, 1 month

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Drum vs. Core

by roger.holmes＠microspot.co.uk

On 6 Jul, 2007, at 18:07, cctalk-request at classiccmp.org wrote: > > From: "Andy Holt" <andyh at andyh-rayleigh.freeserve.co.uk> > >>>> > Back to the original post, does anyone know if there is a difference > between the "operators Exec for a 1900" and the executive used by > engineers and recorded on 7 track mag tape? Would this be of any use? > <<< > > Does that imply that you - or someone you know has such a tape??? Whilst working on my 1301, I was chatting to a friend who was an ICT/ ICL field engineer and later manager into the Fujitsu years. I told him that all copies of 1900 executive have been lost and he said that he might have a copy tucked away but that, if he had it at all it was on 7 track tape and we don't have a deck to read it, but maybe someone somewhere has a way of reading a tape which has not been touched for many years. I will let you know if he finds it, but don't hold your breath, like me he has a lot of buildings and does not go in some of them for long periods. With the 1301 we have a copy of 'Initial Orders' on the drum, a numeric dump of a slightly different version from another machine and also (dyleine?) copies of the original manuscript. Its only two drum bands (so less than 800 instructions), but it is the nearest thing to an operating system that the 1301 had. The 1302 Exec has not survived, nor even details of all the extra instructions in the machine, we know everything about a few, sketchy details from sales literature for others and there are probably a few we know nothing about. A recent documentary series "The Trap, What Happened to Our Dreams of Freedom" had clips of old footage, and in one there was a chap with a book open at a page showing what I immediately recognised as a 1300 instruction summary, the only coloured page in the 1300 programming manual. On freeze framing it and comparing with the 1300/1301 version, I see the arrangement is quite a bit different, and I think it must be a 1302 manual, but of course the image resolution, even on the original 16mm film would probably not allow it to be read, and certainly not off the video now on YouTube. > > anyhow, to answer the question - "it all depends" > > I've only limited knowledge of the Engineers test programs tho' I > think I > have some notes somewhere. > So some of what follows may not be precisely correct. > > Most test programs were normally run under operators exec and were > stored on > a normal program library tape > (these were tapes with a search program (#TAPE) at the start and > the rest of > the programs in any order following.) > > The engineers (raw machine) test tape would have started with a > minimal > exec-mode bootstrappable search program at the > start (really only a program loader - not a full exec). This would > have been > followed by the exec-mode test programs which > were presumably in a bootstrap format. Our engineers usually ran > such basic > test programs from paper tape - this may have been > because that process relied on less of the system being operational > that the > process of finding and loading one from MT. Well, when and if he finds it, maybe what's written on the spool will give us a clue to if its any use or not. > > Of course, as always!, the system faults that one remembers were not > detected by the test programs ... > (On the 1905E one time odd things happened with the Limit register > - that > took some locating; > On the Honeywell dual-processor, one of the two processors started > giving > some wrong results in floating-point - > and as it was (almost) SMP this had effectively random results that > took > some locating) We've had some weird ones with Flossie too. We found a fault three weeks ago, all the read-modify-write instructions were randomly causing a subsequent instruction to fail, about once a minute. This is just long enough to get from the console to the oscilloscope, so you start a program and it seems like the machine is being a bitch and waiting for you to NEARLY get to find out what is wrong, but not quite letting you do it. At the heart of the machine is a shift register which is supposed to have exactly one '1' in it at all times. The duration of the instruction is controlled by how far along the register the '1' gets. With two of us working on the fault, I was probing various signals and eventually we traced the fault to the shift register when my friend shouted over that the fault had seemed to have disappeared. I found that the impedence/resistance of the scope probe on one of 25 pins on one of 4000 cards seemed to make the fault disappear (and reappear when removed). We think we were getting two '1's in the shift register, but anyway, we changed that PCB and all has been well since. Roger.

19 years, 1 month

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A little levity: "computerized FRPG"

by us21090＠yahoo.com

Zane, A few months ago, I came across Flying Buffalo ( http://www.flyingbuffalo.com ), an old PBM company founded in 1970 that is still running. I contacted the owner who still had records of my account from 30 years ago! He says I have 95 cents left in my account, though I didn't ask if that was in 1976 dollars. Kinda pulling this back on-topic, when I played back in the late 1970's, every 2-weeks or so I would receive the new game status on yellow teletype paper! He says, ( http://www.flyingbuffalo.com/history.htm ) they first rented time on a CDC 3300, then later bought a Raytheon 704 minicomputer- over $30,000 total. "Sigh. And it only had 4K of memory!". From there they bought a Poly 88 computer kit, a North Star Horizon and then IBM clones. He also told of a letter from "The Avalon Hill Game Company saying they weren't going to print my ad for "computer moderated pbm" in the classified ads of "The General" (a wargaming magazine) until I sent them a letter of permission from whoever owned the computer that I was using(!)". He also ran into trouble with the zoning inspector: "if you wanted to have a home business, you couldn't have anything that a normal person wouldn't have in their home, and normal people didn't have a computer in their living room." Today he's still using older methods for game play (snail mail, email, fax) but says using the web for entering game play is the next step. Scott ----- Original Message ---- From: Zane H. Healy <healyzh at aracnet.com> To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> Sent: Wednesday, July 4, 2007 9:51:15 PM Subject: Re: A little levity: "computerized FRPG" ... These sound more like the old PBM strategy games rather than a RPG. I think you'd send in your move for the turn, as would everyone else, and then you'd get the results back. ... I've no idea the state of such games, I suspect they're all dead. How many people are going to spend a few dollars per turn, with what was probably a couple week, at least, turn around. This would actually be an interesting area of study from both the gaming standpoint, and the classic computer standpoint. I'd love to see some of the software that was used to control these games, however, I'd guess that most were written by the person running the game, and most of the software has been lost. I do know that many gamers play online, either via email, or other solutions. ... Zane ____________________________________________________________________________________ Pinpoint customers who are looking for what you sell. http://searchmarketing.yahoo.com/

19 years, 1 month

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Symmetric 375

by rescue＠hawkmountain.net

I've aquired one of these... I found a great archive of information at: http://www.berklix.org/symmetric/ However the ftp link to the software archive is no good. There doesn't seem to be a way to contact this person other than by an international call. Anyone know Julian Stacey or have a copy of the Symmetric 375 software ? Haven't tried to boot the unit yet... it does have a hard drive. So... any other Symmetric 375 owners out there ? -- Curt

19 years, 1 month

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CBM 8032 w/8050 dual floppy & Visicalc (Terre Haute, IN)

by legalize＠xmission.com

Ebay # 320135111531 Opening bid is $0.99, local pickup only. It would be a good deal for someone who's close by -- the guy won't ship it due to weight. -- "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download <http://www.xmission.com/~legalize/book/download/index.html> Legalize Adulthood! <http://blogs.xmission.com/legalize/>

19 years, 1 month

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HP150 and other stuff in Dallas/FW area

by g＠kurico.com

From a Craigslist ad (I am not affiliated with the seller, all correspondence should go to the sellers email): http://austin.craigslist.org/sys/367449526.html Body of the ad: I have several old i486 systems, drives, monitors,Keyboards, mouse, modems, ethernet and other cards, vintage software, and guides for mac, apple, basic, etc... Also search user KRLMFL on Ebay for other vintage computers and books! Have 1984 HP 150 touchscreen stack computer system! Looking for anything specific? I have loads of stuff, all from '93 and beyond... Raybob13 at windstream.net

19 years, 1 month

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