test-drb

test-drb@ccmp.vtda.org

101090 discussions

by o2bfrank21＠netzero.net

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19 years, 5 months

Advice for tape drive repair / maintenance (lead-free)

by jtp＠chinalake.com

Mil-Spec in the US is exempt from lead-free. Bonding, whiskers (growing shorts) and the like are know quantities in leaded; and lead-free formulations are still evolving--and improving. A long term concern is what happens to the leaded parts supply. Some of the manufacturers I've spoken with say they will continue to produce lead parts for mil, areo and medical, but will watch the market. No comment on what this will potentially do to leaded parts prices. I have a small stock pile of leaded parts for one application I support, mostly for price stability, and hopefully I will find an appropriate electrical and mechanical bond system by the time I run out. A nice side effect of RoHS, is that many companies are discounting their lead parts. We picked up a nice stock of MicroChip [direct] parts from .18-.40 cents on the dollar for example. Chers,-jp

19 years, 5 months

Pro Toolit docu

by quapla＠xs4all.nl

Anybody interested in a Pro/Toolit V3.0 documentation set? Without the binders, but with the spine inserts and side inserts. Only postage to be paid and docs are in the Netherlands (about 15Kg) Ed

19 years, 5 months

Floppy Manuals

by Billy.Pettit＠wdc.com

Finally, some manuals for 5.25 and 8 inch MPI drives. These are useful because these models were OEM'd to literally hundreds of companies. Some had a different connector, used hard sectoring, etc. There were dozens of different colours. And many used their own labels so you didn't know who actually made the drive. But for all the hundreds of configurations, the mechanics were the same (except for pulley changes to 50 cycle, and capacitor change to 220V AC). If you are playing around with old floppies, you might find these manuals useful. There is an amazing amount of common mechanics and circuitry. http://www.bitsavers.org/pdf/cdc/discs/77715900_9428_HwMaint_Sep85.pdf and http://www.bitsavers.org/pdf/cdc/discs/75897465_9404B_floppyMaint.pdf One of the things I did then was create and track all the different configurations. I know that at one time, I had more than 60 colour schemes on the 8 inch floppy. We tried to avoid doing a separate manual for each config. Instead the basic manual was sent along with an Errata sheet for unique features. These multiple configurations are what eventually killed the maintenance manuals. The documentation department was getting bigger than the engineering group! It wasn't possible to OEM hundreds of configurations and document each with a separate manual. A poll of the customers showed that most only needed interface data for design. So schematics and parts lists and wire lists all went the way of the dinosaurs. Designers were sent engineering drawings on request. Lest you think this is an exaggeration, my notes show that we had more than 2500 separate configurations of the Hawk, a 14 inch cartridge drive (10 MB). I also see that there were more than 500 configurations of the CMD, another 14 inch cartridge drive (96 MB). There was even a room that had the different configurations charted on the walls - all 4 walls. I understand the feeling of those on this list about maintenance manuals. But they didn't have to live with this nightmare. All the mini companies and the early PC companies wanted to differentiate their products. Compatibility was anathema. If customers could read their disk on another system, they might buy it instead of yours. Using different formats, sectoring, interface connectors were all part of protecting market share. But companies trying to fulfill all these unique requirements were drowning in the details. Support finally became impossible - so a generic approach was taken. Then further simplification was done until only a fluff manual was done. Billy

19 years, 5 months

5.25 Floppy Application Notes

by Billy.Pettit＠wdc.com

For those of you who are working with old 5.25 floppies and trying to build your own data recovery circuits, I loaned Al two old MPI Application notes. He has posted them: http://www.bitsavers.org/pdf/cdc/discs/77653447_5inchPrecomp_Aug83.pdf and http://www.bitsavers.org/pdf/cdc/discs/75897469_5inchFDD_Fmt_Jan80.pdf There's a lot of information here that might be useful in understanding some of the early formats and data recovery techniques. The first one also includes circuits and wave shapes using the WD1691, WD 179X and NEC 765.) Billy

19 years, 5 months

Humor - Kludge Komputer

by Billy.Pettit＠wdc.com

I also gave Al several humorous articles from the early 1960's. Originally they ran in Datamation. If you've never read about the Kludge Komputer Kompany, you might enjoy a laugh. http://www.bitsavers.org/pdf/datamation/

19 years, 5 months

Bell 103 Datasets

by Billy.Pettit＠wdc.com

Jules Richardson wrote: Tony Duell wrote: > I can't help with dates, but I do have a few old ex-GPO modems in the > collection. > > The Modem 2B is a large box (about 16" square and 7" high from memory. > It's 300 baud, original and answer. The front panel opens by undoing 2 > captice screws at the bottom and then hinging it up (there's a little > 'stay' to keep it open). Insider are 4 plug-in modules -- PSU, > Demodulator, Control, Modulator, with testpoints, fuses, and adjustments > on the front panels. Hmm yes, we have one of those at the museum; it's a wonderful bit of construction! I've been unable to work out if the 2B was the UK's first foray into modems or not though - was there ever an official 2A, or maybe a 1B or 1A that were even earlier? (I'm off over to the museum tomorrow, but I don't think any of the ex-GPO lot will be in to ask) There are some really good UK telecomms websites out there, but unfortunately whilst they cover phones and exchanges and test equipment, none of them seem to provide any details on the GPO modems... cheers Jules ------------------------------- I asked a friend who is a historian on British telegraphy if he had any data or dates. Here is his reply: Billy Pettit wrote: > > > Bill the question is: what are the first UK modems and when did they > come out? Can you help establish a time line? Billy: Nothing in any of my reference books. Might be worth an inquiry to the BT Archives: http://www.btplc.com/Thegroup/BTsHistory/BTgrouparchives/index.htm Bill Billy

19 years, 5 months

HP 2000F'

by rickb＠bensene.com

> Rick wrote.... > > Z999 was also an interesting account --- it was the "system > >overhead" account. > I'm not so sure about this (and I have the source). There are > no "default" > accounts present when a 2000/Access system is loaded. There > isn't even an A000 account. All accounts must be manually > created and none are supplied on initial distribution tapes. > There were general conventions put forth like some accounts > were not to be created because they were reserved for HP > products, but that wasn't coded into the OS anywhere that I > am aware of. I have never heard of a "system overhead" > account. If there is, I've certainly learned something new. I > will go back and dig for confirmation on this. Off the top of > my head, I think the Z999 account was reserved for containing > the text files of the source of the operating system (if you > had purchased the source), or maybe for the BASIC system > diagnostics (initial system confidence test). Of course, I'm > much more familiar with 2000/Access than 2000F, so perhaps > this is something that only existed on F and no others. I > dunno. Wierd. I believe that the NAM-, and Z999 thing were part of 2000C and 2000C'. I may have accidentally implied that this existed in 2000F and beyond. It didn't. We tried. > > > In TSB, data files had to be pre-allocated to a given size, > and all of > > the blocks were "claimed" as part of the creation process. For > > example, doing a "CRE-FILE,10000" would create a 10,000 block file. > Generally true, but that depends on the file type ;) Again, this likely was under 2000C or C', which I believe only supported text file types. > > > Normal user accounts were limited to perhaps 100 to 200 > blocks of storage. > "Normal" user accounts were limited to whatever the system > administrator typed in as the account block limit when > creating the account in question. > It could be anything. The limit you could specify for each > account had a maximum of 65535 blocks. You could not issue a > CRE command for a file larger than that as a result. When the NAM-, trick was pulled, the 64K block size limit seemed to be removed. The system would try to create a file of any size specified. My recollection is that in normal cases, the space on disk had to be contiguous, so if there wasn't enough contiguous space to create the file, the create would fail. But, in the case of the "overhead" account, it appears that this restriction was lifted, and it'd hunt all over the disk for unused blocks and claim them, which really slowed the system down, and, if too large a filesize was specified would cause the system to crash, as it'd run out disk space. When we did the NAM-, trick, then did a "CATalog" command, the account was listed as Z999, and not the account we were logged into originally. There seemed to be no way to "escape" back to the original login account without logging off, and dialing back in. Interestingly enough, if we did a big file CREation, we could just shut off the teletype, and the CREate would continue to run (as evidenced by the other teletypes stopping I/O activity) until complete, then the login would be terminated. It appeared that the carrier loss interrupt on the IOP, or the communications between the IOP and executive were "tied up" during the CREate process. Whatever the case, it's clear that the "CREate" operation was a blocking operation. The installation we had at our high school (actually, the system was owned by what was called the Multnomah County (Oregon) Intermediate Education District, which served a number of middle schools and high schools in East Multomah County. Since the system served a lot of users, disk space was limited to 100 or 200 blocks. Usually Freshman and Sophomore students got 100 blocks, and Junior and Senior students got 200, because the projects were larger. A local community college (Mt. Hood Community College) had their own 2000/Access system, and user accounts were given significantly more disk blocks than we were allowed. As you said, it's all site-dependent in terms of the amount of disk space allocated for each account. I visited the data center at MCIED at one point in time. At the time, I believe that they were running 2000C. There were two CPU's, one that ran the TSB executive, and another that did I/O. The machine had a multi-platter "washing machine" style disk drive (top load), and an HP 9-track tape drive. I believe it had 32 phone lines attached to it. The modem bank was in a back room, and consisted of a bunch of Bell 103 datasets (later upgraded to 1200-baud datasets, I think once 2000F came around). The CPUs I believe were 2100's, and there was a paper tape reader/punch unit. There was also the "fixed head" disk, and one could use the SANctify (as A000) command to make a program resident on the fixed head disk for much faster access. Swapping activities also occurred on the fixed head disk. I know that it existed, because the fixed disk "crashed" a few times, resulting in multi-day outages. Once 2000F came around, the fixed head disk wasn't needed, and reliability increased quite a bit. At first we had only ASR-33 teletypes, but once 2000F rolled around we started getting some DECWriter II's that could do 1200 baud. What a difference that made. Downside was that the DECWriters didn't have paper tape, so we had to resort to loading programs pre-punched on tape (we had a bunch of offline ASR33's for tape preparation) on one of the online ASR-33's to load new programs, then migrate to the DECWriters for test/debugging. > You can pretty much forget trying to get up 2000A or 2000B. > They required fixed head disks which just aren't to be found. Seems to me that it might be possible to build a pretty simple emulator for the fixed head disk device using either Battery-Backed static RAM, or perhaps fast flash memory. The tough part would be emulating the DMA cycles. > For 2000E, you need just one cpu, paper tape reader, and 7900 > disc drive. > Neither firmware nor mag tape required. Need that 12920/21 mux though. We never had 2000E, nor 2000A/B. On 2000/E, without a tape drive, how were backups done? The service bureau started with 2000C, and upgraded along the line to C', F, then added a second system that was running 2000F', then both systems were upgraded to 2000/Access over a period of time. Sometime in the early '80's, with the advent of microcomputers, schools started building up their own systems with BASIC (our high school built an IMSAI kit, and a Sol-20 while I was there), and started using these with 8K-BASIC to supplement the timeshare systems. I believe sometime around '84 or '85, the TSB systems were decommissioned, and offered for sale. Some acquaintences I know tried to pool financial resources to acquire them, but the IED wanted a LOT of money for them, even though they were quite antiquated by that time. To my knowledge, they sat for quite some time, and then were sold to a scrapper, who mercilessly destroyed the systems to reclaim the gold. I kept in touch with my teacher for a period of time after I graduated, and they had started using Apple II's as the primary teaching machines. Last I saw him, they had a Corvus shared disk drive connected to "networked" Apple II's. I then lost touch with him after the school district re-organized, and I've tried many times to try to find him, but to no avail. > For 2000/Access, you need two cpus, 7900/7905/7906/7920 > drive, 7970 tape, firmware, and 12920/21 mux. If your cpus > are 2100's, then you also must have a paper tape reader. > > The IOP firmware has been located for 2100, 21MX/M, and > 21MX/E. These can be copied, so that isn't the huge deal it > used to be. The 12920 muxes are still hard to find, the > 7900's are somewhat hard to find. The rest is fairly easily > obtainable these days. I'd love to find the pieces to put a system together, but given the scarcity of parts, and the costs involved, it's probably way beyond my means. Worse yet, as time goes by, the stuff becomes more and more scarce. Probably have to settle with memories of those fun times. -Rick

19 years, 5 months

WPS Files into Modern Wordprocessor

by compoobah＠valleyimplants.com

Wasn't there something for DECwrite that would open these? Can't recall if it shipped as standard or not, and I'm still in the process of moving my VMS from my Multia to a 3000/300X so DECwrite isn't up yet. Perhaps someone else could check. DECwrite is included in the VMS Hobbyist layered product PAK

19 years, 5 months

I8008 / Scelbal - Mark 8

by Billy.Pettit＠wdc.com

Jos Dreesen / Marian Capel wrote: It is an emulation of a 8008 machine I might build, (Time Permitting) -------------------------- This reminds of something I wanted to post to the list. I found my original Mark 8 PCBs. I've been preparing them to sell on Ebay, or someplace. These are from the original run made for the magazine article. They are still in the plastic bags, in the original box, have all the purchase order and shipping papers. Hard to get much more provenance on an item this old. Before I sell them, I scanned them into the computer. I don't think they can be posted - copyright problems? So those interested in the scans, let me know. If someone wants to take a chance and post them, let me know too. In the same box, I found most of the documentation, parts and PCB for the EBKA Familiarizer. I've been scanning that in, including the monitor listing, schematics and assembly manual. I didn't know I had it but the package includes some product mailers, a catalog of options, some advertising flyers and so on. I'm haven't scanned them in yet. I've written a small article on the EBKA and what I can remember of the designer. Been trying to contact him - lost touch with him 25 years ago. There are two other pieces I need to find before putting the EBKA on the market - the 1702 programmer and the master I/O PCB. I know the box number they are in and will try to reach them over the Christmas holiday. Now if I can just find my PAIA 8700. I bought it from the writer of the RE magazine article, so it is the one in the photographs. These three items will, I hope, generate some interest. And bids. Billy

19 years, 5 months

RTL - was Build your own Apollo Guidance Computer

by Billy.Pettit＠wdc.com

James B. DiGriz wrote: I believe the prolific Mr. Lancaster wrote an RTL Cookbook. <http://en.wikipedia.org/wiki/Resistor-transistor-logic> Unfortunately I don't have a copy. jbdigriz -------------------------- I think I have a copy of that book at home in Pleasanton. I'll be flying up Saturday morning and will have a look in the book case. If so, I should be able to get some scans of the pertinent sections for you. Do you live in the Bay area? I know copies of it have shown up on eBay in last 18 months, usually going for less than $10. Billy

19 years, 5 months

early IC ident: Sperry 1M4

by hilpert＠cs.ubc.ca

(Speaking of early ICs...) Slim chance, but I'll ask: I have a small plastic box of (what we now call) integrated circuits. Inside are twenty-five (unused,NOS) 10-pin flat-pak ICs, but with pin 6 absent. (Very cute, there is a cardboard holder with each IC nestled in it's own cutout in the cardboard.) The ICs are stamped: SSI <-- logo (Sperry Semiconductor Incorporated?) 1M4 <-- type 6546 <-- date code On the box is a label with: MICRONETS from SPERRY SEMICONDUCTOR (SPERRY RAND CORPORATION) TYPE: 1M4 S.O.#: 20613 <-- Shipping Order # ? CUST.P.O.#: 17762 <-- Purchase Order # ? I like the term MicroNets, from a time when it was not universally agreed upon to call them ICs. Obviously I'm curious as to what they are - can't be too complex with 10 pins and given the period - but before I sit down with an ohmmeter and power supply figured I might as well ask if anybody might know. (Sperry made a lot of stuff, so it's too much to presume they were used in UNIVACs, but when did UNIVACs move to ICs?)

19 years, 5 months

Advice for tape drive repair / maintenance

by Billy.Pettit＠wdc.com

Chuck Guzis wrote: Remember "Madman Muntz"? :) Ahh - there's a flood of bad memories. What a bunch of utter crap he turned out. Two or three functions on one vacuum tube. Remove parts one at a time until the set doesn't work. Then add the last one back in. Sheet metal >from tin cans. High voltage wires with poor shielding. You've brought back a lot of memories, but not pleasant ones. He was one of the true characters to come out of our field. Billy

19 years, 5 months

Targa/TIGA/??? was Re: TMS340x0

by kelly＠catcorner.org

> -----Original Message----- > On Behalf Of Chris M > Sent: Monday, December 11, 2006 3:33 PM > > I remember there being a product by AT & T which was > capable of manipulationg "microdots" (micropels?, > thereby creating screen resolutions much greater then > was common in those days. It was a boardset and may > have been built around the 34010 (not sure about that > though - I think the product was called Targa, and I > could have confused Targa and TIGA). I remeber the AT&T TARGA. Output was to a RGB monitor. Input via tablet with a puck and a wand. They had it running on a Wyse PC/286. I wrote a converter to the Amiga IFF and PC GIF, but I can't find the source any more. I worked at the video lab for the County College of Morris (in New Jersey) back in 90-92. They also had some SGI stuff and some film printers for the PC. All networked via ethernet. Pretty advanced for a community college. Kelly

19 years, 6 months

Build your own Apollo Guidance Computer

by Billy.Pettit＠wdc.com

William Donzelli wrote: > I think a bigger factor here was the consistentcy of switching time. All of > Seymour's design are incredibly tight on switching time. He liked to line > up signals so they would reach the next gate at the same time without > requiring a clock. Having only one gate switch time would ease design. In > all of his designs that I have worked on, he made flip flops and adders out > of individual gates. Again to have exact control of the switching time. This makes no sense. In every ECL family I have seen, when gates are assembled onto one die to make a logic function, the sum is always faster (often by a good amount) than if the same design was done using individual gates. Even if the individual gates are hand picked for speed, the complete logic function will be faster. And there is nothing to keep anyone from hand picking the complex logic functions for speed, as well. ---------------------------------- Seymour Cray did not like to use clocks. For example, his designs call for all the outputs of an adder to be perfectly aligned. He also did not like carry propagation, and wanted all the carrys out at the same time as the data. I've never seen LSI that could achieve this on 64 bit operands. Compare the speeds of some of his arithemetic units, especially the parallel multipliers, to LSI contemporary to his design. --------------------------------- There is also the speed gain of having more computing logic per board. For example in an individual gate design, the extra 2 inches of microstrip traces on the board, plus all the extras involved with getting the signal on and off each chip package, can add up to a significant part of a propagation delay of a gate. And, with more complex boards, the machine could get smaller, with a speed increase gained there as well, as the backplane (backnest?) would get smaller. ---------------------------------- But the switching time of even one gate is longer than the 2 inches of foil. His designs actually use the layout to deskew circuits. And he was big on cordwood packaging to eliminate the length of signal runs. Signals going off a module in all of his designs, are carefully timed and include the foil length and the board interconnects, be they wire or coaxial. All of what you say was true and carefully considered during design. Even where the modules were placed in a chassis was taken into account. I remember one chassis was completely re-laid out, to put the carry circuits in the center of the chassis because they had the longest propgation paths. ----------------------------------------------- > And to eliminate any un-necessary logic. There are no unused gates in any > of his computers. This is certainly a valid reason, and for some of his later designs I can see where an ECL ALU (100181, for example) may have too many extra things. Ok, perhaps a bad example, as I do not think Cray designs use ALUs, or 100K, but it is what springs to mind. But, with something like an and-or-invert gate, or even a multiplexer or demultiplexor, the off the shelf designs are basically minimized. I know the Cray-1s ECL was something like MECL III or 100K, and certainly whoever the chip maker was could have supplied some basic logic functions beyond a gate or two. I think the extra effort to use them would have been minimal, with a great payoff. --------------------------------- When he left CDC, he looked at commercial logic families. And I believe he did do a design with MECL III. CDC proper moved on to MECL 10K for the Cyber 170s and MECL 100K for the STARs and ETA systems. Some CDC designs also used proprietory logic designs. But by then commercial logic suppliers were able to do a better job than in-house designers could and they were cheaper. Most of the in-house foundries were sold. CDC's was, and so was DEC's and Data General's. IBM moved on to be the power house foundry it is today. Makes you wonder who was right. Meanwhile, Seymour moved into more exotic logic trying to get more speed. I think he was working on a weird gallium-arsenide wafer scale design at the time of his death. At the time of the 6600, 7600 and Cray 1, there was no commercial family that could equal the speed of the Cray designs. Some came along (10K/100K) but they were real power hogs. Every gate had complimentary outputs. Every signal had to be terminated. The heat generated was so great that every IC had a heat sink under it, and the heat sink went to a freon cooled cold plate. I spent 4 year designing with MECL 10K. The experience was enough to convince to get out of design and go back to the field. It was a miserable family to work with. And I can assure you that there was skew on the outputs of any of the LSI blocks, but really bad on the 10181. Even with the special carry circuits, it took weeks of wire tuning to get the 96 bit floating point adder to work. We used to go back to the source (Seymour's design in the 7600) and marvel at it. 5 years after he designed it using transistors, we were still trying to equal his performance with MECL. ------------------------------- > Miserable servicing? As someone who spent literally years tuning wires in > Seymour's designs, I have to agree. His machines were very demanding to > impossible to maintain. Just before it died, I spent a few hours on the > 8600. None of us on that machine believed it could be maintained! And the > math models all gave the MTBF as a negative number! I once heard that one of the big boxes in a computer room that hosted a Cray would have a fancy tag like "Disk Control" or something, but that was actually where the field engineer lived. --------------------------------- On my last field site, my office was called "Spares." -------------------------------------- Billy

19 years, 6 months

Advice for tape drive repair / maintenance (silicon)

by jtp＠chinalake.com

>Silicone is pretty mushy stuff. I wonder if a polyurethane elastomer such as Lexel might work a bit better? >I use it for caulking around water and it's very sticky and sets to a fairly firm texture. >Cheers, >Chuck Oh, it's 'mushy'; used it to feed very fine paper w/o deforming it. It gets a bit of paper dust on it and feeds very nicely. It doesn't work for a pinch-pickup. I had access to fun industrial stuff in the long ago, but I've since used a number of 3M, Loctite silicon/poly/ure electronic encapsulants and consumer/commercial sealants (RTV and heat). I am sure there is stuff that takes to high density and speed better, but my expertise in this area is finite. Cheer, jp

19 years, 6 months

Cottonwood BBS is operational!

by drewbrasil＠yahoo.com.br

Cottonwood BBS is back online and operational! After much trial and error, I've got all the right pieces put together... So dust off your old modem, and give Cottonwood BBS a call. It's presently the only known Commodore dial-up BBS in existence! I apologize to anyone who tried to call before... The VoIP line I tried to use didn't work out... So I'm back with a new number, a regular phone line, and NO line noise! Call now at +1 (951)242-3593 For detailed information on the BBS, and tips on connecting, check out the Cottonwood BBS informational website: http://www.wiskow.hpg.ig.com.br/index.htm -Andrew aka Balzabaar (SysOp) _______________________________________________________ Voc? quer respostas para suas perguntas? Ou voc? sabe muito e quer compartilhar seu conhecimento? Experimente o Yahoo! Respostas ! http://br.answers.yahoo.com/ Message was sent through the cbm-hackers mailing list

19 years, 6 months

EXAByte EXB-8500 tape drive available

by vax9000＠gmail.com

It's condition is unknown. It is taken out from a external SCSI case, and the HD from the same case works. The face panel is lost, but other parts look good. If you want it, you pay actual shipping from Ohio, US. Otherwise I will dispose it to the city computer recycling program (not to reuse, but to recycle the metal and plastic I guess). vax, 9000

19 years, 6 months

Build your own Apollo Guidance Computer

by Billy.Pettit＠wdc.com

William Donzelli wrote: Adding just ten more chip types will not significantly increase manufacturing overhead. How many parts total were on the Cray-1 BOM? 10,000? 20,000? making it 10,010 or 20,010 is not going to strain the inventory folks. Also, by adding just ten more chip type, the total number of chips in the system will have gone down - perhaps by ten percent. That will greatly increase yield. Back in those hand-placed hand-soldered surface mount days, board errors were far more likely to be bad solder joints (using that old fashioned solder! horrors!) than misplaced parts. One of the Cray-1s faults was the somewhat miserable servicing requirements, and the crummy downtime that forced it. Fewer parts would have increased uptime (although many of the issues with the machines were not chip related). -- Will -------------------------- I think a bigger factor here was the consistentcy of switching time. All of Seymour's design are incredibly tight on switching time. He liked to line up signals so they would reach the next gate at the same time without requiring a clock. Having only one gate switch time would ease design. In all of his designs that I have worked on, he made flip flops and adders out of individual gates. Again to have exact control of the switching time. And to eliminate any un-necessary logic. There are no unused gates in any of his computers. So I don't think inventory count was a factor. It was just his design phiilosophy - minimum logic, exact timing. There is a great book on this: "Design of a Computer: 6600". Al has it on his site; well worth downloading and reading. Miserable servicing? As someone who spent literally years tuning wires in Seymour's designs, I have to agree. His machines were very demanding to impossible to maintain. Just before it died, I spent a few hours on the 8600. None of us on that machine believed it could be maintained! And the math models all gave the MTBF as a negative number! Billy

19 years, 6 months

Other Bazaar Boards

by wsj＠garlic.com

HI, I saw your post about, what ever happened to John Bell. We were friends in high school, but I lost touch with him. Yesterday I learned he passed away. He is listed as deceased on our high school web site. Do you know any other information about John? Thanks, Wayne http://classreport.org/main/classdirectory.asp?dname=/usa/ca/san_mateo/smhs… The John Bell 6502 board used to be advertised in the back pages of pre-1980 Byte magazines, along with a selection of other JB cards. I seem to recall the 6502 card was minimal-chip system essentially aimed at "embedded processor" type applications. So I don't think it came with a preprogrammed EPROM; you were expected to develop your own firmware for it. They had another bare board for a video display terminal based on an Intel 8085 (basically an implementation of the circuit in an Intel application note) and they also sold some low-cost interface cards for Apple II parallel interfacing using the 6522 VIA chips that were then popular in Commodore Pets. I remember building a couple of those JB interfaces for lab experiments. I wonder who "John Bell" was and whatever happened to him? Arlen Michaels

19 years, 6 months

HP 3000 update and apology to list

by jwstephens＠msm.umr.edu

Apologize in that I found out the system was not an HP 3000, and I raised expectation of several list members about a system. The good news is that it is a nice HP 9000 900, which is nice and fast and has a good copy of HP/UX loaded, and will be visiting my house on a permanent basis when I get back after the new year. I have several of the visualize hp 9000's if anyone is into those, and wants some. I won't discard them but would be willing to share them if someone wants to come get them. Jim

19 years, 6 months

Mag Tapes

by kth＠srv.net

Anyone out there with a 800 BPI magtape drive that could read some RSTS/E DecWord install tapes? Prefer a USA address, due to shipping costs. Would like to make these images available, but don't really want to spend $100 in shipping costs. (5 tapes, about 6 lbs, from 83401)

19 years, 6 months

RTL Cookbook

by Billy.Pettit＠wdc.com

Amazon has several used ones - try http://www.amazon.com/exec/obidos/ISBN=067220715X/donlancastersgurA/ And Don's web page is always fun to visit : http://www.tinaja.com/ Billy

19 years, 6 months

Bell 103 Datasets (was: HP 2000F')

by Billy.Pettit＠wdc.com

Richard asked: Speak of Bell modems, does anyone have a timeline or reference for modem equipment before the phone system was broken up and anyone was allowed to make them? Wikipedia has an entry for the Bell 103 300bps modem, which they say was released in 1962. There is also an entry for the Bell 202 1200bps modem with no date reference. Does anyone else have more complete information about modems before the diversity of manufacturers entered the scene? -- Can't help you on the official time line. But I can put dates to my first contacts with them. I helped build a system for the IRS that used the Bell 101. This was in the fall of 1963. We had both Bell 301's and 103's in the lab. And retrofitted the 101's to 301's early in 1964. All of these units were transistor based. The first remote terminal systems we shipped to DARPA used racks of 101's driving teletypes. This was also late 1963. The first non-Bell data set I worked on was in 1967. It was a mature design, IC based, high volume, so probably started in 1966. Billy

19 years, 6 months

RTL - was Build your own Apollo Guidance Computer

by Billy.Pettit＠wdc.com

Chuck Guzis wrote: On 20 Dec 2006 at 11:21, James B. DiGriz wrote: > Now that is something I didn't know and find very much worth looking > into. Any quick pointers to info on RTL operating in this mode? I'll dig through my old literature. I recall that Motorola offered an "Experimenter's Kit" of about 6 of their TO-99 packaged milliwatt RTL circuits with some non-digital application notes. Anyone still have the little booklet that came with this kit? Cheers, Chuck ---------------------------------------------------- I know that RCA also had a nice set of Application Notes for introducing RTL. I'm not certain I still have them - came out in 1962. Some of the early RCA data books still had them inside. Maybe one of our data book collectors has copies. If so, I'll be glad to scan them. Al, does your data book collection have an RTL book? And I have seen an RTL CookBook-like manual with a bunch of circuits in it. Would have been in 1969-70. I believe I bought it England. Had a green cover, paper boards. I want to say Plessey published it, but the synapses aren't firing on this one. Maybe one of our English members remembers it? Any one have a copy? Billy

19 years, 6 months

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