test-drb January 2011

test-drb@ccmp.vtda.org

130 participants
209 discussions

by wbblair3＠yahoo.com

Did a little research myself and it appears that the Nook has a micro-SD slot whereas the latest Kindles no longer have SD slots.

13 years, 11 months

Kindle and bitsavers

by tshoppa＠wmata.com

> how much of the archive would fit onto one of these devices? Bitsavers is well over 120 Gbytes last time I checked, most of it PDF's. Depending on generation of Kindle you get 1.4 to 3.3 Gbytes of user storage. Last time I made a DVD-R set of bitsavers content it filled circa 28 DVD's. > how much of an advantage would one of these devices hold over a laptop? The Kindle screen is smaller than most laptops but the portrait orientation is a better match to typical printed text than a laptop's landscape orientation so the screen real estate is way better utilized. Kindle displays by do not include ornamentation and all that other crap around the edge of the window and that's a true win for screen real estate usage too. I can't believe it's 2011 and most typical laptop and desktop display usage is devoted to crap like borders and icons and buttons. Toolbars are the crappiest idea in the world. When I see someone who has installed so many toolbars in their browser that half of the screen is taken up with them I just want to scream. Pixels per inch on the kindle is on the high end of current consumer displays but the same is true for many laptop displays too. Power consumption is way lower on the kindle. ("digital paper" vs LCD technology) Tim.

13 years, 11 months

No subject

by tshoppa＠wmata.com

> how much of the archive would fit onto one of these devices? Bitsavers is well over 120 Gbytes last time I checked, most of it PDF's. Depending on generation of Kindle you get 1.4 to 4 Gbytes of user storage. Last time I made a DVD-R set of bitsavers content it filled circa 28 DVD's. Tim.

13 years, 11 months

Favor to ask ....

by evan＠snarc.net

If anyone in the Silicon Valley area is going to Jane Smiley's lecture @ CHM tonight, and if you * AGREE * with my recent posts about ABC vs. ENIAC, then please e-mail me privately. I have a favor to ask. Thanks.

13 years, 11 months

ENIAC ....

by jonas＠otter.se

Definition of "computer" from the Oxford Dictionaries Online: an electronic device which is capable of receiving information (data) in a particular form and of performing a sequence of operations in accordance with a predetermined but variable set of procedural instructions (program) to produce a result in the form of information or signals. a person who makes calculations, especially with a calculating machine. I suppose that would make ENIAC a computer, since the program is variable, even if only by moving lots of wires. /Jonas

13 years, 11 months

Passing of Bill Mayberry, Terak co-founder

by jfoust＠threedee.com

Today I learned that William Mayberry, one of the cofounders of Terak, passed away in August 2010. He started as an EE at University of Illinois where he worked on the ILLIAC. He worked at Sperry Flight Systems. He designed the Space Shuttle MDM system, then went to Boeing and worked on the electronics of the 747, then the flight control and weapon systems of the Apache helicopter. In 1975, he cofounded Terak Computer and became its CEO. He'd always kept me in mind to help preserve his Terak history, and I'm glad to say his family is helping with that. I'm working with his widow to help preserve the materials she has. One of his nephews has an interest in preserving the Terak. Contact me if you could assist with physical rescue in the Phoenix area. - John

13 years, 11 months

Need RL02 Controller for PDP-11/44 Restoration

by michael.99.thompson＠gmail.com

> I read through the blog - if the motors start spinning as you describe > (I envision you mean for a few seconds; please correct me if this is > wrong) _then_ the drive stops spinning, I doubt it's the capacitors. > If the motors _don't_ start moving when you put the drive online, then > that is one component to examine. The motors start to spin up, accelerate for a few seconds and then stop. A few years ago I fixed and RA81 that had the same symptoms by replacing the starting capacitor. > RA81s were at one point, exceedingly susceptible to HDA failure. ?I > don't recall the specific ECO levels, but some version after "E" used > a different glue than its predecessors leading to particulate > contamination leading to catastrophic failure. ?ISTR looking for "H2" > or "K2" drives after that disaster. Two RA81s have tan colored HDAs, one has a black HDA. I think that the black HDAs are the new design that doesn't crash so often. > RA81 drives have a DB25 inside. ?You can plug a terminal in and run > on-board diagnostics and monitor operations. ?You can run with the lid > up or lid down (snaking a ribbon cable out of the drive). ?The molex > connector next to the data connector is to power a small hand-held LED > terminal (I saw one once, used with a high voltage chassis for > particle physics, but the terminal was the same). > > Try plugging in a working VT220 and letting the drive tell you what it > thinks is going on. ?You might find that it's starting to spin up then > not liking what it sees and spinning down. I forgot that I have a DEC Termiflex that plugs into the RA80/81 and the TU81 diagnostic port. I will connect it to the drives this weekend and see if I can get more details on the problem. > Oh... just a detail - you mention locked heads - you _did_ pull the > cord to retension the drive belt, right? ?(for safe transport, the > RA81 has you locking the heads _and_ disengaging the motor from the > HDA by removing belt tension). ?If you didn't do this step, what I > think may happen is the onboard processor will start to spin the > motor, sense no rotation from the HDA, then spin the motor down and > emit a fault code. ?Maybe this is what you are seeing? I saw the pull cable on the right side of the drive. I have used those in the past to replace HDAs or motors. I will make sure that it was not in a position to release tension on the drive. > >> https://sites.google.com/site/ricmwarehouse/Home/equipment/dec-pdp-1144 > > Reading through your blog, I don't think you will have success with > booting 2.11BSD on your 11/44 with a TU81+ unless you have install > media that knows about that tape controller. ?The 2.9BSD tapes I have > require an "MS" device (older OSes might or might not require an "MT" > device). ?Back in the day, there were several incompatible tape > controller types, with different boot ROMs, and your install media had > to match your controller and ROMs (or you had to toggle in the > bootstrap). ?You can install 2.11BSD using vtserver and a virtual tape > drive though. ?Also, if you do get real 2.11BSD install tapes, you'd > probably want to be looking for a TU80 and, IIRC, an M7454 controller > card. > > -ethan I looked at the 2.11BSD setup document and it says that the TU81+ is a supported tape drive. There are two of those drives at RICM, but no TU80. The M8739 KLESI-UA interface for the TU81+ doesn't seem to be common or inexpensive. I think that the RCS/RI guys have one that I could borrow for an installation. It might be simpler to just use vtserver. Thanks for all of the comments. -- Michael Thompson

13 years, 11 months

SCSI hard drives of large form factors

by ian_primus＠yahoo.com

Here's something I was thinking about the other day. I *know* for a fact that SCSI interface hard drives existed with 8" platters. I've never seen one, however. Does anyone know of any specific model numbers, or have any product information or pictures of such devices? Along the same lines, did SCSI interface devices exist with 14" platters? An option for the venerable Fujitsu Eagle, perhaps? I know that Adaptec made a standalone SCSI-SMD bridge board. I have one, although I've never been able to get it to work. I got as far as hand-crafting SCSI commands to try to get it to format the drive, and it would sit there, device active, but the drive never stepped or seeked off the first cylinder. -Ian

13 years, 11 months

Need RL02 Controller for PDP-11/44 Restoration

by bqt＠softjar.se

On 01/26/11 15:00, Michael Thompson<michael.99.thompson at gmail.com> wrote: > I am reassembling a PDP-11/44 from parts for the Rhode Island Computer > Museum. I would like to try an RL01 or RL02 drive on the system, but > we don't have another RL02 controller. > > Do any of you have a M7762 RL11 disk controller board that you could > donate or sell inexpensively for this project? Can't help on that one... > The RA81s won't spin up, so I suspect that I need to replace the > starting capacitors. > > Do any of you know where to get replacement starting capacitors for > the RA80 or RA81 drives? I assume you *are* aware of the power sequence bus of the RA8x drives. Without that one properly terminated, the drives will never spin up. Johnny

13 years, 11 months

OT: DRAM memory controllers within FPGAs

by keithvz＠verizon.net

I was hoping to share my pain with others as a coping mechanism. :) Has anyone else worked with DRAM memory controller implementations within FPGAs? I have been struggling for a couple years to find a workable solution in a hobby environment, first on Xilinx and then on Altera. Both companies seem to push the embedded microprocessor solution, MicroBlaze and Nios II, respectively, as an answer. They both offer a built-in memory controller which makes access to the DRAM much much easier, as it's memory mapped to an address region. But the problem is that there is a certain amount of overhead associated with using the processor both in terms of speed and logic utilization. The processors have a maximum speed and making a "gateway" out of the processor doesn't work for any real application. Many people push "opencores" and say there are 30 or 40 open source memory controllers without realizing that all of the limitations eliminate 99% of what's out there, including: Controllers designed for a particular memory architecture/chip type/ bus width Custom busses that aren't documented Some just don't work Require a specific vendor + FGPA because they use proprietary built-in hardware and so on. There are commercial solutions which cost way too much $$$ and often have advanced features which complicate use for the average hobbyist. I need something that has a FIFO-like(or maybe sram-like) interface on it, and that supports single data rate SDRAM. Something simple. Anyone else run into problems with getting a working memory controller for your projects? Thanks Keith

13 years, 11 months

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test-drb January 2011