test-drb January 2010

test-drb@ccmp.vtda.org

187 participants
240 discussions

by ard＠p850ug1.demon.co.uk

A week or so ago there were a few messages about the HP 'Medusa' HPIB chip. While looking for indormation on the custom chips in the HP printer I'm working on from time to time, I cam across some comments that might be applicable. The HPIB interface chip in the HP2531 printer is called 'Phi'. According to HP Jorunal July 1978, it is a silicon-on-saphire CMOS device. It's pacakaged in a 48 'pin' leadless ceramic package, and has the number 1AA6-6004 The Medusa, packaged in a 48 pin DIL package, seems to be a closely related device. The pinot is in the same order, for example. This probably explains the rather curious numbering of the data bus pins on the Medusa (D0, D1, and D8-D15, with D15 as the LSB). The best reference I've found so far on this is the reference manual for the HP12009A HPIB interface for HP1000 machines. It's on http://www.hpmusuem,net. THe earlier version of the manual there covers the Phi-based board, the later version the Medusa-based one. They are very similar.. -tony

14 years, 11 months

OT iPods etc (was Re: Museums)

by tshoppa＠wmata.com

Keith writes: > I'd like to just plug my ipod into my Windows PC, and copy my .mp3's to > it. It seems absurd to me that you can't do this. Forget the huge > bloated management application that is constantly advertising and trying > to sell you something. You can do that... you just don't use the Apple iTunes software to do it. I use GNUpod under linux, but I'm sure it'd work under Windows too. What's ironic is that I use a Microsoft VFAT file system under linux Gnupod to write To an apple device. When mish-mashes of hardware, filesystems, etc., occur Like that in fact it's hard to even think in terms of religious wars anymore. You just plug everything together and it's ugly but it works. It's not as ugly As the Apple iTunes software! There's a lot of generic music devices out there too that don't need the gnupod layer at all. Tim.

14 years, 11 months

General machine cleaning

by jfoust＠threedee.com

At 10:03 AM 1/25/2010, you wrote: >Not sure how it is about taking goo off, but for cleaning up old machines in >general, I like those Magic Erasers from Mr Clean. I haven't looked into >the ingredients, but whatever's in it, they hit the nail of the head. If >you have some machines that have marker writing in stead of an asset tag, >this might take it off. For me, it's worked in some cases and not others. >It will take those general hard to remove scuffs off also. I start cleaning >new machines by first scrubbing them with baby wipes, then a magic eraser. http://en.wikipedia.org/wiki/Melamine_foam "In the early 21st century it was discovered that melamine foam was an effective abrasive cleaner. The open cell foam is microporous and its polymeric substance is extremely hard, so that when used for cleaning it works like extremely fine sandpaper, getting into tiny grooves and pits in the object being cleaned." - John

14 years, 11 months

Large pdp-8/i on eBay

by v.slyngstad＠verizon.net

Tim put his 8/i up on eBay a couple of hours ago. It's worth a look. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=320475395861 Vince -- o< The ASCII Ribbon Campaign Against HTML Email!

14 years, 11 months

museums

by js＠cimmeri.com

> Keith M wrote > > My computer of choice is the Amiga. ... [entire essay] ... Once > something becomes obsolete, it's not often preserved because it seems > to have no value, and then you're posting on goofy forums and paying > $300 years later to get your hands on one. Extremely nice writeup, Keith. The more I think about the subject, the more complicated it is. There's just a lot of factors that go into something having meaning for us, and those factors are going to be different for every person, as well as changing as the person matures or learns more. For instance, I started out collecting machines I had as a young guy -- Apple II, S-100, Mac. But because of the internet, delving into those led by chance into learning about others... never imagined I'd end up with a PDP-11 in my house. You are so right about soul. I will never collect one of my Dell laptops, even though I love them as an appliance.. and I really can't tell you why. Maybe if my first machine ever had been a Dell laptop? For me, at some point machines evolve from being magical to commonplace. Computers when they first appeared in my life really did seem magical... Remember the feeling of your first car vs. buying cars now? Perhaps it is precisely that initial awe of something new is what inures us to certain machines and not to others... Machines that don't wow us now because our initial exposure has passed, might wow others. Or maybe, kids growing up with them will see them as like a toaster -- so ordinary as to be nothing more than a tool... who knows. More, it's being able to comprehend the machine. The machines I collect are ones I can service and fairly comprehend the entire picture of (even if not all the options and variations). Machines today.. whether they be cars or computers... are beyond my currently ability to service or fully understand the innards of... therefore, I'm forced to just accept them as tools that work. John Singleton

14 years, 11 months

Znner diode data

by ard＠p850ug1.demon.co.uk

The quick versions : Does anyone know of a book or website which gives brief characteristics of zemer diodes? The ones we use in Europe tend to have the zener voltage given as a suffix to the part number, but the US ones have 1Nxxxx numbers which tell me very little. The actual device I am looking for info on is a 1N5365 , but knowing where to look in future would be useful. The long version : I've got an HP2631 printer (wide carriage dot matrix with an HPIB interface). When I extracted it from my junk pile, it gave a power-on error (according to the service manual on hpmuseum.net) that was a RAM error. After pulling the case and CPU board, I was amused to see the RAMs were our old friends, 2114s. So I desoldered the RAM that the error code said had failed and fitted a new one. Next time I ppowered on, all hell broke loose. The carriage rammed into the right side plate and the carriage motor breaker tripped. Then the 2 fuses on the PSU board for the +/-20V rails blew, and the status LEDs for the +/-12V regulated supply rails went out. THe last is not too suprising, those rails are regualted down from the 20V ones. Replacement fuses blew at swtich-on Quick checks have indicated that both carriage motor drive transsitors (a 2N5844 and a 2N5886) are shorted all ways round. So is the overvoltage protection zneer between the -20V line and ground -- this is the 1N5365 I mentioned. I obviosuly need to replace these parts -- after finding out what caused the transistors to fail. -tony

14 years, 11 months

Catweasel support for Intel M2FM working!

by snhirsch＠gmail.com

I'm pleased to announce that the maintainer of Linux cwtool has implemented working support for reading and writing Intel M2FM "DD" diskettes as used with the Intellec development systems :-). Karsten did some analysis of raw bit images I sent him and produced a working driver within a week! As a "smoke" test (my MDS800 is not functional at the moment), I duplicated the ISIS-II system diskette and sent the copy to a person with a working system. It boots, catalogs and otherwise looks fine. I have about 20-25 original distribution diskettes for the MDS800 and will get busy imaging them ASAP. Who would be willing to host these? They are "cooked" images, so it would be possible to extract the files >from them with a bit of work. However, they're obviously of the most use to folks with access to a Catweasel board (and an Intellec system). Steve --

14 years, 11 months

General machine cleaning (was Re: Recurring subject: Goo removal)

by brianlanning＠gmail.com

Not sure how it is about taking goo off, but for cleaning up old machines in general, I like those Magic Erasers from Mr Clean. I haven't looked into the ingredients, but whatever's in it, they hit the nail of the head. If you have some machines that have marker writing in stead of an asset tag, this might take it off. For me, it's worked in some cases and not others. It will take those general hard to remove scuffs off also. I start cleaning new machines by first scrubbing them with baby wipes, then a magic eraser. brian

14 years, 11 months

Museums

by wdonzelli＠gmail.com

> Apparently the distinction is headed for the scrap heap. Interesting that "scrap heap" is mentioned. A real museum should have some formal mechanism so stuff does not end up in the scrap heap after the museum fails. Failure can be the loss of funding, loss of space, death of "the main guy", divorce, apathy, or a million other reasons. Recall about a week or so ago I had an informal survey concerning wills, and taking care of collections after the collectors have passed. Results were better than last time - barely. Two. I guess this means there are going to be a lot of Straight-8s and Apple Is scrapped in the next 20-30 years. -- Will

14 years, 11 months

Museum for sale

by js＠cimmeri.com

----- Rich Alderson wrote: I would consider Robert Krten's pdp12.org to be an on-line museum, ----- Dan Roganti wrote: Such a collection is quite admirable and valuable. But using the term "online museum" just *continues* to depreciate the meaning of a museum. Anyone can make a website, take photos, copy documentation, etc, etc, and then call it an online museum. Then who's to say that you ever have to own the equipment anymore in the first place ? =Dan -- mu?se?um (my?-z???m) n. Abbr. mus. 1. A building, place, or institution devoted to the acquisition, conservation, study, exhibition, and educational interpretation of objects having scientific, historical, or artistic value. {American Heritage} By this def, Robert's home (a "place") and website qualify collectively as a modest museum. I think it's better to argue over the aspects of his museum -- such as quality, size, rank amongst others, etc -- rather than what word Robert has likely casually ascribed to his purpose. Evan, when I invite others into my house, I often joke, "welcome to the museum" or if I don't, they call it that. There's casual usages of words, then there's serious ones. John Singleton

14 years, 11 months

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test-drb January 2010