test-drb

test-drb@ccmp.vtda.org

101090 discussions

by mark＠markesystems.com

>> least.. but yeah.. might be impossible to ever really know. I'm just >> wondering why the price jumped to $40+ each all of a sudden! > a very large number of schlock IC sellers all communicate with each > other. They all have a continuous stream of wants or needs that they > exchange. but they make their own prices. The probability is that you > may have hit the original stocking guy with your first query. Querying > any others will result in them looking at the wants that others shared, > or buys, and he saw someone else had it and quoted you the same info. It takes surprisingly little to trigger this effect/behavior. I did a bulk buy of some 1960's era miniature vacuum tubes (500 pcs) for around 50 cents each; the next time I looked, the price from all vendors who had them had jumped to around $3, and it's up to $6 now. (Fortunately the vendor I purchased from originally extended approximately his original pricing to me again.) I think I was - and still am - virtually the only volume buyer of these parts, but the price remains high. I've also had the same experience with other vintage new-old-stock parts. ~~ Mark Moulding

8 years, 4 months

FTGH: HP 100/150 Series Memory Boards (45632, 45631)

by hugh＠blemings.org

Hi, I've been assisting a friend with the deceased estate of a local ham radio operator. In among the myriad RF related items were the following; Qty 5 HP 45632-60001 384kB Memory Module 150 Qty 1 HP 45631-60001 256kB Memory Module 150 http://www.hpmuseum.net/display_item.php?hw=383 We have no way to test, but given the condition we would assume they are working ok. Free for the cost of postage to anyone who wants them provided you cover freight (From Belconnen, ACT, Australia 2616) Happy to ship overseas - contact me off list and I can give dimensions and weight etc. They will be off to generic computer recycling two weeks from now. Cheers, Hugh

8 years, 4 months

Looking for small quantity of grip rings for Boxer fans

by ethan.dicks＠gmail.com

Hi, All, I'm refurbing some of my DEC equipment and I found some dirty/sticky Boxer fans, no surprise. I managed to get one apart, cleaned and lubed and spinning freely, then one of the grip rings shot off into space. I found this reference... http://www.cirteq.com/pdfs/cirteq_technical_manual.pdf The style in question covered on pages 85-86 (metric then standard) One of the comments is next to a diagram of the correct type... "Lug design for sizes 7-9-11-19-23-27" Based on that, it's probably an NG023, since the shaft looks to be 0.250 or slightly smaller not slightly larger. d1 == 0.236" (shaft diameter) d3 == 0.224" (clip ID) s == 0.039" (clip thickness) Has anyone had to buy grip rings for their fan refurbs before? Do these numbers sound right? -ethan

8 years, 4 months

Double Buffer RK11-C

by jnc＠mercury.lcs.mit.edu

> From: Fritz Mueller > But then over at bisavers, I see this: Yes, that's the panel I found the picture of in the RSTS-11 brochure a while back: http://www.classiccmp.org/pipermail/cctalk/2016-November/029104.html The picture in the brochure is not very very hi-res, but Al Kossow recently located some original photos in the DEC section of the archive, and the image you sent the URL for is one of them. I've been puzzling over what this thing is. It looks 'kinda-sorta' like an RK11-C panel (the registers it shows are sort of the RK11 registers), but if you look at the print for the "RK11-C Indicator Connectors: RK11-C-23" (page 34 of the RK11-C Engineering Drawings PDF), you can see the pinout, and it doesn't match. E.g. look at the lower right line of lights on the panel: 4 bits of Bit Counter, a blank, 8 bits of Internal Word Counter, a blank, and three bits of Major State; now look at the RK11-C prints, connector B32: 4 bits of Bit Counter, 8 bits of Internal Word Counter, a blank, Postamble, Checksum, Data, Header, Preamble. Close, but different. One thing I have been wondering about is that "RK11-C" - that implies that there was a -B, etc. I wonder if this panel goes with one of them? (Or perhaps it is a custom prototype?) I have never been able to find out anything about an earlier version of the RK11: the earliest Peripherals Handbook that I have is the 1972 Red/White one, and it only talks about the -C. Also, the Spare Module Handbook (a fantastic resource, it lists the boards in almost every PDP-8/10/11 option) mentions the -C and -D, but no other ones. However, given the example of the KT11-B, which was totally unknown until the documentation for one showed up with the -11/20 in Arizona, thereby proving that there _was_ a KT11-B before the KT11-C (the -11/45's MMU), I would guess that there likely _was_ an RK11-B, and perhaps this panel goes with that (or an earlier one). Any further information would be most welcome. Noel

8 years, 4 months

Double Buffer RK11-C

by jnc＠mercury.lcs.mit.edu

> I'm working on the prints now. OK, done and uploaded: http://ana-3.lcs.mit.edu/~jnc/tech/pdp11/RK11-C-DB_EngrDrws_Dec72.pdf I haven't had the time to pore over them to figure out exactly what the changes do, but they add two buffer registers (ABUF and BBUF), so they probably offer greater resilience to DMA contention on the UNIBUS. I don't yet know if they are used for write as well as read (the RK11-C-DB block diagram in the prints suggests not, as it doesn't show a path from any RK registers to the ABUF, just from the UNIBUS - i.e. only usable on reads), or if there are any user-visible programming changes (I suspect not). For those with an RK11-C, these prints are somewhat clearer than the prints for the 'basic' RK11-C which are online, so although there are a number of changes (see: http://gunkies.org/wiki/RK11-C_disk_controller#Engineering_drawings for info on which sheets have changes), use of these can help decipher some of the hard-to-read pages of the 'basic' RK11-C drawings. Also, the prints for the 'basic' RK11-C are missing a couple of pages: 18 - Disk Cable and Termination 19 - Bus "D" Drvrs and Rcvrs which are present (albeit perhaps modified, for the second one) in this set. Noel

8 years, 4 months

Black anti-static foam corrosion

by COURYHOUSE＠aol.com

let me know if you have a 90 mm summacron f2(?) a nice working one is great! I not good inside but looks ok on the outside let me know... we need it to go on an M2 in a display. Ed# _www.smecc.org_ (http://www.smecc.org) In a message dated 12/3/2016 8:24:48 P.M. US Mountain Standard Time, cisin at xenosoft.com writes: On Sat, 3 Dec 2016, drlegendre . wrote: > Interesting find, thanks for posting this. I've seen this as well. with a > batch of old ICs which had been stored (in black foam) for some 20-30 > years. The leads kind of just stayed behind in the foam.. > My assumption was that the foam was simply hygroscopic, and held enough > atmospheric moisture & pollutants to foster corrosion. There are numerous black foam formulations. I inherited some lenses (including a Leitz Tele-Elmarit 180mm (<250 made)) that had been stored for a few decades in an essentially airtight case with black foam. When I first opened the case, it seemed as though there was liquid in the case, with an intense vinegar? smell. Second time that I opened the case, a few hours later, it was dry and crumbly, and the outer painted surfaces of the lenses were badly pitted and had to scrape bits of the foam off, but NOT at all like water damage. It turned that lens from mint condition and a major rarity, into usable but POOR cosmetic condition (a loss of more than a thousand dollars in value!). (Three other cases had simply disappeared between the time my buddy died and the time that the county let us go through the house.)

8 years, 4 months

DMMCheck (Now a word from a non-sponsor)

by drlegendre＠gmail.com

Quick FYI for the bench-techs in the group. A few months back, I became aware of this device, as well as the others produced by the same fellow: http://www.voltagestandard.com/DMMCheck_Plus.html He's producing several types of low-cost, precision voltage / current / frequency references. Prices are reasonable, especially when you consider the re-cal program. Any of these should be more than adequate for the vast majority of our reference / cal requirements. (I have no connection to the mfr. But I do like the product, and wanted to pass it along.)

8 years, 4 months

Black anti-static foam corrosion

by COURYHOUSE＠aol.com

a loss indeed... Well we have the M2 body and light meter to go on top. All we just need the lens so if you ever find another please let us know! Thanks ! Ed# In a message dated 12/3/2016 8:46:15 P.M. US Mountain Standard Time, cisin at xenosoft.com writes: > > (Three other cases had simply disappeared between the time my buddy > > died and the time that the county let us go through the house.) On Sat, 3 Dec 2016, COURYHOUSE at aol.com wrote: > let me know if you have a 90 mm summacron f2(?) > a nice working one is great! I not good inside but looks ok on the > outside let me know... we need it to go on an M2 in a display. The Summicrons (I know there was a 50mm and a 90mm, but I don't know about 35mm) and the M series bodies, had been in those three cases. And his two PBM-1000's (Micropro computer) were dumpstered.

8 years, 4 months

ISO Tekelec Chameleon 32 mfm disk

by aek＠bitsavers.org

Slim chance, but does anyone have a working Chameleon that I could clone the software off of? They are 40mb MFM drives, I just bought two, and both units are missing the drives, making them boat anchors. Or, slimmer yet, if someone has the software on floppy

8 years, 4 months

Growing the hobby

by cctalk＠snarc.net

Hello cctalk'ers, We at the Vintage Computer Federation would like to thank everyone for making 2016 an incredible year. Most of you know us by now, but just in case you don't -- we're a 501(c)3 non-profit created a year ago to organize the Vintage Computer Forum, VCF East, VCF West, and the official VCF Museum (at our NJ headquarters). Our goals are simple -- to empower collectors and spread awareness of computer history. We accomplished great things in 2016. We doubled the size of our museum, hosted the 11th edition of Vintage Computer Festival East, resurrected the former Vintage Computer Festival West, and joined forces with the Vintage Computer Forum. Now we?re asking for your help to keep the momentum going. Can you make a tax-deductible gift to us this holiday season? Over at our contributions page you?ll find four options ? Binary ($10.00), Phreaker ($26.00), 555 Timer ($55.50), S-100 ($100), and Variable (enter your own amount). If you?d like to do something truly awesome, and you happen to live in or will be traveling to the San Francisco / Silicon Valley area, then bid on lunch with Lee Felsenstein through our friends at CharityBuzz (https://www.charitybuzz.com/catalog_items/lunch-for-3-with-personal-computi…). Lee is a technical and social media legend ? he was a spark behind Community Memory, moderator of the Homebrew Computer Club, and a top engineer for both the Processor Tech Sol-20 and Osborne-1. Bring a few friends, have lunch with Lee at your mutual convenience, and we?ll pay the bill! Where will your money go? We are planning even more things for 2017 and beyond. Vintage Computer Festival East XII will be held March 31 through April 2 at our museum. We are currently planning Vintage Computer Festival West XII and will announce the dates soon. We?re considering expansion of the Festival to other cities, we?re looking to incubate additional regional chapters, we are planning to offer more resources online, and we?re preparing a slew of improvements to the physical museum. If you thought we were active this year, then 2017 is going to exhaust us ? but we love every minute of it! If you want even your news even more frequent and granular, then you?ve got options! Read our blog at vcfed.org, join the discussion forum there, like us at facebook.com/vcfederation, and follow us through twitter.com/vcfederation. Finally, if you have questions or comments, then please feel free to contact me directly. Thank you, Evan Koblentz Director, Vintage Computer Federation Evan at vcfed.org

8 years, 5 months

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