test-drb June 2012

test-drb@ccmp.vtda.org

193 participants
237 discussions

by brian＠polibyte.com

Down in Macon, GA my dad has a DEC that we would like to send to a good home. He purchased this several years ago from a man in north Georgia who said it spend the 1990s answering the phone at a utility company. My dad kept it in his classroom while he was a high school technology teacher, but now that he's no longer teaching it's gathering dust on his carport. There's a VAXstation 3, DECvoice unit, two hard drives, and a tape drive in an enclosure on wheels. There's also a VT420 terminal. You'd need a truck, ramp, and at least two strong people to load and unload this. You can see some pictures of the equipment at http://www.flickr.com/photos/puerexmachina/sets/72157622981044137/ Please pass this on to anyone you think might be interested! -- All the best, Brian Pitts

12 years, 1 month

P800 boards

by tshoppa＠wmata.com

>> >> Seems excessive... I seem to recall you need log2(n) - 1 bits, which >> >> would be 3 bits (32-bit ECC needs 4 bits). >> > Doesn;t that assume the 'extra' bits are known to be correct. Those >> > can be in error too (even if the'real' data bits are correct), >> >> No, it doesn't. See Wikipedia's Hamming code page (asking for SECDED >> redirects to it) for a brief treatment of the subject, or any of many >> more detailed treatments of coding theory for more. > > I am missing something here... The OP says that adding 3 bits to a 16 bit > word is enough to be able to correct any single-bit error. > > Now, consider those 16 'real' data bits. If any single one is in error, > that generates a new 16 bit word, and each of these much give the same > output 16 bit word after error correction. So it would appear to me that > there have to at least 17 possible input words (the 'correct' one, and > the 16 wach with one bit fillped form the corrrect one) that give the > same 16 bit output -- that is what is meant by correcting single bit erorr. > And yet adding 3 bits only gives you 8 times as many possible data words, > which doesn't seem enough. The example I know, is the MK11 memory box. ECC there is done at the single-error correction, double-error detection level on 32-bit words. This takes 7 check bits. I find the most satisfying illustration to be the MK11B print set, there's a very nice 11x17 page in large type, illustrating how all this is done with XOR gates. I find this much more digestible than the usual mathematical equation stuff found in textbooks. That's a brilliant page. It shows how to, by eye, to read the XOR gate outputs to identify the error syndrome uniquely, with just a few words. Many fewer words than I used in this paragraph!!!! If you didn't want double-error detection it would take 6 check bits per 32 bit word. Maybe the implication that there is 3 check bits per 16 bit words, assumes single-bit correction and the actual ECC logic is working on 32 bit words. If the ECC was working on 16 bit words, it would take 5 check bits. Tim.

12 years, 1 month

BASIC rom compatibility

by rampaginggreenhulk＠yahoo.com

Ill wager they must have been very illegal clones Diane. Do you remember anymore specifics? And with her statement I dare anyone to tell me the real early even vanilla clones arent collectible.

12 years, 1 month

BASIC rom compatibility

by rampaginggreenhulk＠yahoo.com

assuming an empty socket (IBM mobos typically have empty sockets), chances are if you dropped IBM roms into a clone mobo, while it may not boot into BASIC in the absence of a floppy or hard drive, would it work if you jumped to so and so?

12 years, 1 month

A Teletype Model 43 and a 1938 Army dual teletype with paper tapes

by ard＠p850ug1.demon.co.uk

> > I was at a storage unit this evening, picking up yet another couple of > free DEC machines. The guy unloading the machines also had a couple of > teletypes. One was a pretty standard Model 43 (all plastic case). > It had a 300 baud interface, not serial port. He said he knows it works I am wondering jsut what a '300 baud interface' is if not a serial port. It sounds like it might be a current loop interface. I thought the Model 43 had both that and RS232 as standrd, but it does depened on the PCB at the very back, behind the PSU. I _think_ that standard Model 43s can do 110 or 300 baud. -tony

12 years, 1 month

interesting Quora post on Marklar

by lproven＠gmail.com

On 12 June 2012 16:54, Zane H. Healy <healyzh at aracnet.com> wrote: > > I rather wish they'd kill of HFS+, weren't there rumors of moving to ZFS a > few years back? I don't know what happened but I suspect it might have been something to do with the Oracle takeover. This has caused problems with Java use on Linux, for example. Oracle won't permit others to host the JVM in a repository any more, for instance. -- 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

12 years, 1 month

interesting Quora post on Marklar

by jon＠jonworld.com

On Tue, Jun 12, 2012 at 11:54 AM, Zane H. Healy <healyzh at aracnet.com> wrote: > I rather wish they'd kill of HFS+, weren't there rumors of moving to ZFS a > few years back? > > ZFS in OSX died due to SUNW->ORCL licensing changes, IIRC.

12 years, 1 month

A Teletype Model 43 and a 1938 Army dual teletype with paper tapes available.

by jimpdavis＠gorge.net

Oh no! Not another baud .vs.BPS.vs.data rate gentleman's argument! But, What is a 300 Baud interface? Current loop maybe? jim Scott M wrote: > I was at a storage unit this evening, picking up yet another couple of > free DEC machines. The guy unloading the machines also had a couple of > teletypes. One was a pretty standard Model 43 (all plastic case). > It had a 300 baud interface, not serial port. He said he knows it works > because he ran it to a computer at 300 baud that then converted the > signal to serial so that it could communicate "normally". He said the > 300 baud interface makes it more of a pain, but more cool at the same > time. He is looking to unload it right away. The other teletype was > all metal, built into a small table, had an Army Corps label, a tape > read/writer?, a box of blank "new" paper tapes on spools about 5/8 inch > wide. Also a second auxiliary? teletype unit was built into a very > small adjacent table. This one had several "new" rolls of paper approx > 12 inches wide. The secondary teletype had keys too, but I am thinking > the primary with the paper tape was used for input and the secondary > was used for output. The guy said it was used with the MARS system. > There was an interface box too, probably to connect to a ham radio, > but the radio was not present. The guy said he got it from a retired > Air Force General who had kept it as a souvenir. He said he has all the > original manuals that go with it at home. He said it is complete and > reportedly working. The only thing wrong was some of the plastic covers > on the individual keyboard keys had deteriorated and were loose. > However considering the year, 1938, it was in remarkably good shape. > The dry Colorado air is pretty easy on most equipment, and this was > yet another example of that. > He said cannot ship it because it is too heavy, but I know that places > like "The UPS Store" can pickup, package, and ship items like this. > There is a UPS Store nearby that might be able to do the job. (I had > a 100+ lb IBM machine shipped this way a few years ago for about $200). > Anyway, the guy is Matt. I am not going to post his email address, but > if you want to contact him, email me and I will forward your email to > him. I can also give you contact info for the nearby UPS Store. Matt > took some pictures with his smartphone for me, and once he emails those, > I will put them on a website. > > Scott > > > > >

12 years, 1 month

I am looking for a few MINDSET items, in particular a BASIC cartridge, s/w

by rampaginggreenhulk＠yahoo.com

no??? What about on disk? ------------------------------ On Sat, Jun 9, 2012 5:07 PM PDT Curt Vendel wrote: >Basic was never released on rom cartridge. Yes it was mentioned in marketing materials but was never developed onto rom > > > >Sent from my iPhone > >On Jun 9, 2012, at 5:50 PM, Chris Tofu <rampaginggreenhulk at yahoo.com> wrote: > >> >> turns out none of my units work anymore. Short of pulling the roms... I may have the service docs. I know I have the marketing guide. >

12 years, 1 month

A Teletype Model 43 and a 1938 Army dual teletype with paper tapes available.

by scott.m.18＠atsgate.com

I was at a storage unit this evening, picking up yet another couple of free DEC machines. The guy unloading the machines also had a couple of teletypes. One was a pretty standard Model 43 (all plastic case). It had a 300 baud interface, not serial port. He said he knows it works because he ran it to a computer at 300 baud that then converted the signal to serial so that it could communicate "normally". He said the 300 baud interface makes it more of a pain, but more cool at the same time. He is looking to unload it right away. The other teletype was all metal, built into a small table, had an Army Corps label, a tape read/writer?, a box of blank "new" paper tapes on spools about 5/8 inch wide. Also a second auxiliary? teletype unit was built into a very small adjacent table. This one had several "new" rolls of paper approx 12 inches wide. The secondary teletype had keys too, but I am thinking the primary with the paper tape was used for input and the secondary was used for output. The guy said it was used with the MARS system. There was an interface box too, probably to connect to a ham radio, but the radio was not present. The guy said he got it from a retired Air Force General who had kept it as a souvenir. He said he has all the original manuals that go with it at home. He said it is complete and reportedly working. The only thing wrong was some of the plastic covers on the individual keyboard keys had deteriorated and were loose. However considering the year, 1938, it was in remarkably good shape. The dry Colorado air is pretty easy on most equipment, and this was yet another example of that. He said cannot ship it because it is too heavy, but I know that places like "The UPS Store" can pickup, package, and ship items like this. There is a UPS Store nearby that might be able to do the job. (I had a 100+ lb IBM machine shipped this way a few years ago for about $200). Anyway, the guy is Matt. I am not going to post his email address, but if you want to contact him, email me and I will forward your email to him. I can also give you contact info for the nearby UPS Store. Matt took some pictures with his smartphone for me, and once he emails those, I will put them on a website. Scott

12 years, 1 month

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test-drb June 2012