test-drb November 2014

test-drb@ccmp.vtda.org

200 participants
279 discussions

by brain＠jbrain.com

I know this is not an electrical forum, but I thought perhaps someone has seen what I am looking for. For an application, I am looking for a relay that is connected to 12V through a switch, with the switch voltage also going to the middle of a SPDT relay contacts. * If I energize the latch once, for the time the button in pressed, the relay flips "on" and the middle relay contact sends power to the NO contact * If the energize the latch a second time, for the time the button is pressed, the relay flips "off" and the middle relay contact sends power to the NC contact. The circuit works with an open relay of the kind they used to use in garage doors (push button once, and door goes up, second press makes it go down...) But, we need a sealed relay to beat the weather (it's for a lineman's bucket truck we own). Simulating this with some electronics and two relays won't work (well, it would work, but it's for my father, and he really wants a electrical/mechanical relay solution, like he has, but weathertight). I thought for sure there was such a thing as a D-type FF in relay format, but all of the magnetic and mechanical latching relays I see online use two separate coils to operate, which means two switches, and that won't work (no more signal paths available in this application). I must not know what to call what I am looking for, and was hoping someone had a better name for this type of thing or a suggestion of where to look... Jim -- Jim Brain brain at jbrain.com www.jbrain.com

10 years

Facit 4046/4047 Reader-Punch Manual Available

by kylevowen＠gmail.com

I scanned in my two manuals for the Facit 4046/4047 that I have and gave them to Al at bitsavers. He got them uploaded the other day (thanks again, Al!), so feel free to check them out. Setting up this reader-punch without it is a big pain (I've tried). http://bitsavers.trailing-edge.com/pdf/facit/ Enjoy, Kyle W4GNU

10 years

KL-10B in DEC-20 [was RE: Who's rewired their house for this hobby?]

by jnc＠mercury.lcs.mit.edu

> From: Rich Alderson > We have a non-running 1090 here at the museum Oh, good, then you have a machine to run ITS on (along with ones for WAITS and Tops-10! :-) Just kidding (mostly); ITS did run on a KL (without hardware mods), but I'm not sure which model it was; it was a pretty early one. I know it had the external memory bus, and I _think_ it had the RH20s (I know it had RP's of some kind, I think MassBus, because one of them was dual-ported and the console 11 booted off of it, and I don't think it had whatever PDP-10 disk controller the KA's had). I guess it was a KL-B, then? Whichever one it was, anyone who wanted to run ITS on a KL would probably want the same model - I know ITS had custom microcode (in part to emulate the MIT pager, which had a different page size from the BBN/DEC one, and also because ITS used some custom instructions which had been added to the KA's), and although one could probably get that to run on a different model KL, it might be (an unknown amount of) work. But, completely seriously, ITS is an amazing system, and although there are a few running on simulators, I'm not sure anyone has it running on real hardware. That would be Very Cool. Noel

10 years

Apple Network Server, Anyone seen one?

by alexmcwhirter＠mojovapes.net

This were produced by apple in the mid 90?s. The ran AIX and were pretty large machines. I?ve been looking for one for a couple of months to no avail. Considering they were only produced for a year should i assume that they have all be crushed?

10 years

IBM RT - AOS / SAUTIL

by jonathan.chote＠gmail.com

Hey everyone, I've seen a few topics on here in the past regarding the IBM RT, so thought I'd ask around here. I'm installing a new ESDI drive in my 6150 Model 135. I've mostly been researching the old Usenet group and the FAQ to work bits out but now I've become stuck. It seems the fail-safe trick to getting non-IBM ESDI units working is to perform a blind format using the AOS SAUTIL disk. Does anybody have access to this disk or disk image or know where I can find one? My AIX 2.2.1 / VRM disk returns "I/O error writing configuration record" during format which I believe is because the drive needs to be cleared. IBM PC RT Diagnostics won't recognize a drive and format until it has the configuration record. Any help tracking down that SAUTIL disk or assistance would be much appreciated. Thanks! Jonathan

10 years

Cyber ECL Wiring

by bpettitx＠comcast.net

Eric Smith wrote: "Another approach is to use single-ended on a module, but only differential between modules. To do it properly, the differential signals between modules need to be twisted pairs." You are correct. Eric, have you seen a Cyber 170 chassis? There is no back plane. Every signal uses twisted pair wire wrap from module to module. It was horrible to build, wire mats inches thick. We used to allow field engineers 10 minutes per signal line for engineering change orders. Provided, the line did not need to be tuned. Tuning was done by changing wire length. It was not elegant by later standards but was very very fast for the era. One of the downsides to using differential wiring throughout the system was the manufacturing time measured in months. Of course, they sold for millions or tens of millions of dollars so it was worth this approach. At the time, early 1970's, there was not a lot LSI available in ECL. So most of the Cyber series, and early Crays used SSI. Chip count was never as important as speed. The one MSI that I remember being critical was the 10181, an ALU chip. To use it and keep signal lengths short, the arithemetic chassis was laid out with the ALUs in the middle and the registers around them in a circle. The carry tree was at the center of design. Internally, word size was a bastard mix of 60 and 64 bits. The higher performance models were a mixture of discrete modules from the 7600 and ECL modules from the Cyber 173. It's hard to visualise with today's technology. The multiply unit took an entire chassis! Memory took multiple chassis. All I/O cables and interchassis cables were differential tuned cables. All I/O had to use the same length cables. As Chuck mentioned, 400 Hz MGs provided the power. It was distributed to the chassis where the diodes were mounted in alunimum bars, cooled by freon. If you get a chance sometime, look at the Cray-1. The part where you sit is all power components. The circular logic chassis was primarily to keep wire length short. Seymour tried to build it using an absolute minimum of chip types, only two for much of the logic. He felt that MSI and LSI stole speed from his design. Billy Pettit

10 years

Apple IIe/GBBSPro v1.3/MSS100 help

by tpresence＠hotmail.com

Hey guys,I've been working on trying to get an internet based BBS setup on my apple IIe.I have GBBSPro 1.3 running on the IIe using a super serial card in slot 2, switched to run at 2400BPS. I have the modem set to external, and the modem type is "Hayes Smartmodem 2400".I am using a straight through 25M-25F between the MSS100 and the super serial card. The ssc selector block is pointing to "terminal". There is no null modem in the setup.The MSS100 is accepting remote connections, and the serial port is also at 2400BPS N81. The settings for Access: remote, DSR logout, DTR wait, and Modem Emulation are checked. I have tried all flow control options and none.When I telnet to the remote access port (2001 or 3001) it connects but immediately disconnects. Once in a while I see an modem initialization string on the terminal before it closes. The string is "ATX3S0=1&C1&D2S2=128". I understand what the init string does, but I'm not sure if its coming from the MSS100 or from the BBS. During this period, the bbs is just sitting at the "waiting for call" screen.If I turn off DSR logout, I do not get disconnected, but I'm not connected to the bbs.Anyone have any experience with this? Are there any settings that must be changed?Thanks in advance,Kevin? 2014 MicrosoftTermsPrivacy & cookiesDevelopersEnglish (United States)

10 years

SMD replacement options?

by tshoppa＠wmata.com

http://www.mbiusa.com/mbi_000010.htm

10 years

Who's rewired their house for this hobby?

by bpettitx＠comcast.net

Will wrote: "On the other hand, ECL does not suffer from the spikes, burps and farts TTL tends to make. Late model Cybers tend to have very little in the way of filtering, simply because the ECL load is "nice"." ECL, if done properly, uses a terminator on every signal line. On MECL it is usually it's 560 ohms to -5.2v or 220 ohms to -2.2 volts. Because most circuits have two ouputs, signal and not signal, termination gives you almost a steady load. This termination and balanced lines gave the Cybers very fast signal propagation with little noise like Will mentions. And it requres a lot less regulation and filtering requiremets for the power supplies. It was a joy to design with ECL, if you ignored the horrendous power required. We could weld with the Cyber power supplies! And if the freon cooling failed, you got some interesting smoke within seconds. Billy

10 years

Vince Briel computers

by gkaufman＠the-planet.org

I have to admit I'm getting very frustrated with the situation. I ordered from Vince in August, and paid $218 in advance. His website is still accepting payment via Paypal, and it appears that others have also not received shipment of their Superboard III orders. I guess he's in San Diego, anyone have any direct contact information other than his email address? - Gary On 11/10/2014 2:38 AM, cctech-request at classiccmp.org wrote: He seems to come and go. I ordered a mini-altair from him in September of 2013 and got it around a year later.

10 years

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test-drb November 2014