test-drb

test-drb@ccmp.vtda.org

101090 discussions

by roger.holmes＠microspot.co.uk

>>> In hindsight, could the DEC-20 or RISC version of it >>> had marketing and other bad luck changed ,and >>> today replaced the PC in many applications? >> >> Six bit based architectures all died with the rise of the IBM S/360 >> family. DEC, CDC, Univac. >> >> It also did not help that many of these old line mainframe >> architectures were getting hard to extend. For the DEC 36 bitters - >> what does one do after the 18 bit address pointer, with two neatly >> stuffed into a 36 bit word? A kludge. What does one do after the 36 >> bit address pointer? A worse kludge. > > I kind of suspected that was the case. Did anyone make a large 48 bit > machine? > If you mean physically large, then yes. However on the 1301, addresses range only from 0 to 3999 (decimal). Probably not what you meant really.

16 years, 4 months

[Fwd: [Mandrakeot] Hey Gene - Amiga stuff]

by woyciesjes＠sbcglobal.net

FYI, for the Amiga developers around here.... -------- Original Message -------- Subject: [Mandrakeot] Hey Gene - Amiga stuff Date: Mon, 21 Dec 2009 21:54:21 -0500 From: Ric Moore Reply-To: mandrakeot at mdw1982.com To: mandrakeot at mdw1982.com http://feeds.arstechnica.com/~r/arstechnica/open-source/~3/KX0p_xQ7x7g/know… Thought you'd get a kick outa this one. Ric -- --- Dave Woyciesjes --- ICQ# 905818 --- AIM - woyciesjes --- CompTIA A+ Certified IT Tech - http://certification.comptia.org/ --- HDI Certified Support Center Analyst - http://www.ThinkHDI.com/ "From there to here, From here to there, Funny things are everywhere." --- Dr. Seuss

16 years, 4 months

HP 3000 micro GX with MPE/V OS. need tape

by ss＠allegro.com

Hi, Where are you located? Can you use DDS (DAT) media? I'm one of the "too busy" people, but perhaps I can get some time in between now and the New Year. On Dec 17, 2009, at 9:45 PM, g-wright at att.net wrote: > I'm back to try this again. I need a boot tape for a HP 3000 > Micro GX machine. Does anyone have a working machine > or a tape. I can use almost any media. I had 2 list members > say they would help but they seem to be too busy and its > been 6 months. I would really like to get this going. > > Thanks, Jerry > g-wright at att.net >

16 years, 4 months

MDS Series IV schematics on line

by aek＠bitsavers.org

under http://bitsavers.org/pdf/intel/MDS4 thanks to Bob R. for the loan of the originals still looking for a couple of other multibus hardware manuals isbc286/10, 386, 486S, 214, 215, 221 disk, 550,552 ethernet nj

16 years, 4 months

Hackable DVD players (was Re: Amiga Demo's)

by ethan.dicks＠gmail.com

On 12/14/09, Alexandre Souza - Listas <pu1bzz.listas at gmail.com> wrote: > Tony Duell wrote: >> I suspect such players are too expenice _new_ for me even to consider >> buying, and contain suffieicently complex custom ICs that it's a bad idea >> to buy one for which manufacuters spares are no longer available. > > Want something hackable? Look for an AP660 from Apex. No service manual > but full listing of the ROM :oD I have one of those. Unlike most cheap-o consumer devices, there _is_ detailed internals data available - detailed enough to retool the firmware. It's not full circuit diagrams and datasheets, but from the software side of things, much, much better than most devices. It also has a bog-standard IDE DVD transport, unlike less expensive devices. That's the model I was contemplating mounting the IDE-CF rig on for the Click! experiment (since I already have some 3.5"-drive-bay-PCMCIA adapter frames on hand). My main AP660 is on the fritz right now, but it's probably PSU issues. Fortunately, I have a parts unit I can use to verify that everything else is good with. I've had one since it was new and been very happy with it. -ethan

16 years, 4 months

Burroughs B5500 and successors (Was: Happy DEC-20 Day!)

by alanp＠snowmoose.com

> > From: Ben <bfranchuk at jetnet.ab.ca> > >> Because the Burroughs B5500 and B6700 computers used a word >> containing 48 bits of data, but also extra bits that described the >> type of the data which played an important role in programming the >> machine, I would consider that series sufficiently out-of-the- >> ordinary to attempt to discuss here; This also included the Burroughs/Unisys A-series systems that were made into the early 90s. The A-series systems used a 52-bit, tagged word. 1 bit of parity, 3 bits of tag and 48 bits of data. I don't recall how the addressing worked and Al has my papers on the architecture, so I can't look it up ... alan

16 years, 4 months

Running Computers Cold

by ethan.dicks＠gmail.com

On 12/9/09, Zane H. Healy <healyzh at aracnet.com> wrote: > At 9:55 PM -0800 12/8/09, Chuck Guzis wrote: >>On 8 Dec 2009 at 21:19, Zane H. Healy wrote: >> >>> Okay, this is the first time I've ever had to worry about this. When >>> is it to cold to run a computer? It's 35F out in the garage, and it >>> is supposed to get a lot colder tonight. I just shut the dehumidifier >>> down (to cold to run it) and setup a heater near the computers (and >>> other stuff I don't want to freeze). >> >>It seems to me that Ethan would be the perfect one to answer this. >>35F is probably a heat wave at the South Pole. > > Except I don't think they run their computers outdoors! :-) But we do use outside air to cool them. It's free except for the power to push it around. (Oh... and +35F is never seen at the Pole - the record is +7.5F, and I've personally been around for +7.0F). As for the extreme case, we've had computers malfunction when outside access doors were left open and -80F air came in directly, bypassing the blowers and the louvers. On a day-to-day basis, the room with the 14 racks that was AMANDA (it was shut down earlier this year after a 10+ year run) shed about 35-40kW of heat with indirect access to outside air with some measure of automatic and manual thermal controls (covering up open cable panels and stuffing blankets in hatches in addition to thermostatic controls on air blowers). If we let the room get over about +55F, the high-voltage supplies for the photomultipler tubes would go into thermal shutdown (ultra-dry air at 650millibars doesn't have much heat capacity). OTOH, and more to the point, if we let the room get much colder than about +35F (say +25F or colder), a specific rack of digital hardware that was adjacent to the floor vents feeding cold air to the high voltage supplies would malfunction until the temp came up to the high thirties to low forties. In another location entirely, central Ohio, I used to rent the basement of my mother's typing and typesetting shop. The building was a late 19th C/early 20th C brick "shotgun" commercial space with a former storm-cellar-type access to the basement. As such, cold air poured from the modern back door, down the basement stairs, and into the space I ran PDP-8s, PDP-11s and a VAX-11/730. One of my jobs at the time was hacking PDP-11 assembler on an 11/23. The basement would routinely get to +40F, and sometimes colder if the wind was from the right direction (the water pipes had electric wraps). I couldn't personally stand to work in that environment without a heater pointed at me, but the computers ran fine. The lone device that had problems was an LA-180 printer I used for listings. It worked down to about +45F, but colder than that, I speculate that the rail lubricant got too viscous, because it would blow carriage motor fuses until it warmed up. I quickly learned not to print on cold nights. I'd say that if you keep things at or above freezing, you are probably perfectly fine. Magnetic media is a lot more sensitive than ICs in terms of cold soaking. One thing to watch for is to not power up cold-soaked electronics. The current inrush is likely to blow ICs (the internal bonded wires between the die and the frame, mostly). I've thawed machines that were left in unheated buildings over the winter at McMurdo - ordinary temps around -45F or so. Specifically in that case (ultra cold, powered off), there are known and published "max rates of rise" of temps to minimize the risk of permanent damage >from thermal expansion. A good rule of thumb is about 2-3 degrees per hour. What I did with the cold-soaked computers was to throw them into a lab freezer at -40F for a few hours, then into a lab environmental chamber at -30F that I would tweak up about 5 degrees every couple of hours. When the chamber was up to about +20F, I threw the equipment in a lab refrigerator. The thaw process took two workdays, but 100% of what I treated that way survived (no hard disk - these were floppy-booting diskless PCs that ran from a Novell server). If it gets really cold (+0F, say), I'd bring the disks in the house and leave the CPUs powered off until the garage temps are back around +32F. ICs can be stored down to -40 typically, but not operated at those temps (and especially not put through a power-on cycle at those temps). So that's my experience and observations of cold and computers. Take away from it what you will. -ethan

16 years, 4 months

Happy DEC-20 Day!

by RichA＠vulcan.com

Long live the system that is a major improvement on its successors! Rich Alderson Vintage Computing Server Engineer Vulcan, Inc. 505 5th Avenue S, Suite 900 Seattle, WA 98104 mailto:RichA at vulcan.com mailto:RichA at livingcomputermuseum.org http://www.pdpplanet.org/ http://www.livingcomputermuseum.org/

16 years, 4 months

paper tapes

by aek＠bitsavers.org

did anyone on the list buy these http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=220526045578 i'm curious what the interest was

16 years, 4 months

need specs for mag DJ920

by brianlanning＠gmail.com

I just got the monitor for free from craigs list. (and a lead on possible other equipment) Does anyone have the specs for this monitor? Google searches have been fruitless.

16 years, 4 months

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