test-drb June 2013

test-drb@ccmp.vtda.org

216 participants
271 discussions

stupid programmers, was Re: Old UNIX Systems

by elson＠pico-systems.com

Most never accepted the validity of the concept. "Just get an adequate computer. That's management's problem." OK, another story. A friend of mine was a Physics student at Rolla (University of MO sub-campus) and also very good at programming/analysis. He had a roommate who was an ME student, and just learning programming. He saw his professor fiddling with one of those 15-tile puzzles, and said "Hey, I could write a program to solve those". His prof said it would be a good exercise, and gave him an account on the 370/168 at the main campus. He wrote it, and tried it, but it kept running out of time. He assumed an infinite loop, and eventually mentioned it to the Physics student. My friend sensed a teachable moment and said, Hmm, you have 16 nested do loops >from 1 to 16. Do you know how many total iterations that is? The guy whips out his trusty HP45 and starts calculating. My friend smiles, as he already knows that 16^^16 will not be computable on the calculator. So, they trudge over to the comp. Sci. building and he shows the guy the System/360 storage and timing estimates book, and they work out that JUST the loops, themselves, will take something like 10 billion years to complete. He eventually chopped out useless iterations and got a program that ran in a minute or so. So, the moral is that there are relatively modest problems that can become TOTALLY un-computable with a poor algorithm. No computer ever made could have finished his poorly thought out program. Jon

10 years, 12 months

large qty of early Apple/Mac needs to leave my warehouse

by sales＠elecplus.com

I have a large qty (1 entire 20x20 foot room) of early Apple/Mac stuff that needs to leave the warehouse. We really don't deal in Apple products, and I have sat on these for the past 16 years, hoping someone would appreciate them. The are a few Apple II, LCII and LCIII, PowerPro, Mac Classic, Mac 128, Mac 256, lsome newer towers (still 16+ years old), lots of monitors (from the old tilt-screen to 17" multimedia and tall word processing screens) and all-in one machines, some lasers, some extra cards for the Apple IIs, floppy drives (single and double), a little bit of game software, some manuals, some boot disks, some utilities and word processing, Claris, over 70 keyboards, etc. Also lots of modems, adapters, cables, etc. We are bringing in laptops by the truckload, and I REALLY need the space. The first person to offer $2000 will receive nicely boxed and palletized merchandise. Some of the all-in-ones have cracked housings; if you don't want those, I will take them the recycle center. If nobody claims these this week, the whole lot is likely to get recycled. Cindy Croxton Electronics Plus 1613 Water Street Kerrville, TX 78028 (830)792-3400 phone (830)792-3404 fax AOL IM elcpls _____ No virus found in this message. Checked by AVG - www.avg.com Version: 2013.0.3345 / Virus Database: 3204/6450 - Release Date: 06/29/13

10 years, 12 months

Speaking of NeXT - mono video to VGA?

by toby＠telegraphics.com.au

I seem to recall having a conversation on the list not too long ago about the difficulty of converting NeXT mono video to VGA. At first I had thought this might need something as sophisticated as digital conversion, but somebody said it was only an electrical matter. What's the deal? What needs to be done - anyone know? I have a Cube with the fading type of NeXT monitor, you see... thanks, --Toby

11 years

Battleship terminal BB61

by jws＠jwsss.com

When the sailor gets into a battle station situation he could take the terminal with him for either armor, or to use the keyboard to bash someones brains out, or strangle them with the cable. Looks appropriate for the USS Iowa, or any of the 4 Iowa class ships. http://www.navsource.org/archives/01/0161020.jpg page of photos is at if you want to see more BB-61 http://www.navsource.org/archives/01/61g.htm Thanks Jim

11 years

C64 Power Supply Replacement Options

by brain＠jbrain.com

Since I support the CBM crowd, I've had more than a few people send me comments over the past few years, asking when I might consider offering a replacement power supply for the home computing machines (VIC-20, 64, 128, +4) Initially, I resisted for liability reasons and certification costs. But, I decided earlier this year to put off those questions for a bit and just see what might be technically and economically possible. I've chased a few ultimately fruitless options, and I thought I'd see if some fellow soul on this list might have some ideas. Obviously, the first thought was a complete custom supply. My interest was never in power design, so I am ill-equipped (and uncertain of my abilities) to design such an item myself. Thus, I started looking for a manufacturer that could design one. Absolute requirements: 5VDC at 4.3A. 9VAC at 9VA unregulated To this I added my requirements: The 5VDC be a switching PSU output ISO C13 input power jack (so I can support many areas without building custom power cords 115/230 switchable design (or two very similar designs that can handle the 2 voltages) My cost under USD$30.00 per unit. Enclosed finished case, or be able to fit in a commonly available case design. Someone put me in touch with Stontronics overseas, which worked on an initial quote. But, I think the C13 and 115/230 requirements scared them off. I solicited information from Bear Power Supplies in the US, but they did not seem too keen on continuing the discussion, so I have nothing from them. I've also tried overseas suppliers, but I have not yielded fruit yet. I've asked all the PSU suppliers on globalsources.com and alibaba.com I have struggled to find a custom PSU manufacturer that can handle a suitable design. Being frustrated with the direct approach, I thought I'd try a different path, and find a 9VAC or 5VDC single output power supply. I found a single output large amperage 5VDC supply, but then I got stumped on finding a way to synthesize a 9VAC isolated output from the 5VDC. A simplistic approach would involve creating a harsh +-9V square wave, but it needs to be at least .5A (to run the cassette deck on the 64/128), and I worry that the noise on a square wave @ 1A would wreck the audio and video noise level in the machine, which is not the best to start with. Even ignoring that, I need to double or quadruple the voltage to get the 18V rail to rail voltages I need. On the 9VAC front, I had little luck finding a suitable 9VAC supply that is 45VA or 63VA to support a 5VDC at 5A draw while leaving enough for the 5A 5VDC output. As well, I am not sure I am equipped to design a switching 5V PSU from a 9VAC source. With the old power bricks getting more brittle and prone to failure each day, I feel some sense of urgency to find some solution for folks. For liability reasons and because 5VDC is the more important voltage in the units, I myself lean towards a small box that turns 5VDC into 5VDC and 9VAC, but designing a voltage doubler/sine wave generator/isolation transformer solution is far beyond my comfort zone. If this is not a complicated task, I am wondering if someone on-list is up for a small freelancing effort to design such a unit. It needs to contend with the issues outlined in this PDF (http://www.ide64.org/power_des.pdf) in that the noted design won't work as is since I think people need to be free to use the power switch on their machine. There might not be a reasonable solution, but I thought I'd share in case I am missing an option. Jim -- Jim Brain brain at jbrain.com www.jbrain.com

11 years

Next MO question

by ball.of.john＠gmail.com

I dismantled my MO drive years ago and photographed it. After you take it apart for the first time you learn that the top and bottom covers can pivot and the drive becomes more easier to work on. I have it all in my Photobucket Album (http://s11.photobucket.com/user/ballsandy/library/Computer%20related/NeXT%2 0MO?sort=3&page=1) I was /one of/ the first to notice the leaking caps. It stemmed from my drive spinning uncontrollably and was assumed that the caps on the motor control had gone. This was just before we began to realize that the reason that systems like the Macintosh Portable and the IIci weere dropping like flies was because the surface mount capacitors and reached a point in their life where they had begun to leak. We now know that just because one might of failed, they all probably have and they will do some REALLY weird things as they die. The small radials that are used on the motor control are present elsewhere on the drive as well. I have plenty of reason and speculation that these are what has caused the massive 99% failure rate of the MO drives and that a full replacement will bring back the drives. As Mr. Strickland said the SCSI bridge causes translation problems but other than that, the Canofile and the two OEM variants made by Mass Microsystems and some other company for the Mac market are otherwise identical.

11 years

laser printers headed for recycle

by sales＠elecplus.com

DEC LNO3, qty 2 Genicom 7170 HPII HPIII HPIV HPVI Okidata 810 and similar Brother HL10h Various others Probably 3-4 pallets total. None tested recently, some may be missing parts, all will probably need new pickup rollers after sitting so long. Somebody make offer, or by Thurday these go to scrapper. Cindy Croxton Electronics Plus 1613 Water Street Kerrville, TX 78028 (830)792-3400 phone (830)792-3404 fax AOL IM elcpls _____ No virus found in this message. Checked by AVG - www.avg.com Version: 2013.0.3345 / Virus Database: 3204/6450 - Release Date: 06/29/13

11 years

Next MO question

by cclist＠sydex.com

Was the MO drive used on the NeXT cubes a standard 650MB unit, or was there something special about it? (e.g. sector size, encoding, format, etc.)? Anyone have an extra to spare? --Chuck

11 years

Understanding the bin, sbin, usr/bin , usr/sbin split

by lproven＠gmail.com

Fun with PDP-7s and other early Unix hosts... http://lists.busybox.net/pipermail/busybox/2010-December/074114.html -- Liam Proven ? Profile: http://lproven.livejournal.com/profile Email: lproven at cix.co.uk ? GMail/G+/Twitter/Flickr/Facebook: lproven MSN: lproven at hotmail.com ? Skype/AIM/Yahoo/LinkedIn: liamproven Tel: +44 20-8685-0498 ? Cell: +44 7939-087884

11 years

G4 update

by sales＠elecplus.com

On Cory's suggestion, I tried just one stick of memory. Still no video. Tried the other 2 sticks, and it boots to question mark on either stick, but not both together. Pulled 2 sticks 265MB PC100 with same specs from drawer, it now boots to ?. Still will not boot the Live Debian 3.0.6 i386CD. Somebody give this guy a new home? Cindy Croxton Electronics Plus 1613 Water Street Kerrville, TX 78028 (830)792-3400 phone (830)792-3404 fax AOL IM elcpls _____ No virus found in this message. Checked by AVG - www.avg.com Version: 2013.0.3345 / Virus Database: 3204/6450 - Release Date: 06/29/13

11 years

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test-drb June 2013