test-drb April 2019

test-drb@ccmp.vtda.org

134 participants
129 discussions

by dj.taylor4＠comcast.net

This I didn't know. I bought a Tektronix 4207 color graphics terminal without a keyboard recently.? Finding the correct keyboard part number seemed to be a process with great uncertainty, the VintageTEK folks said the correct one was a 2468.? One of these was for sale on ebay for $300 - no way was I paying that much! So I tried one that looked like the keyboard in the TEK catalog of that period, but with a different part number. The connector looked like the right one though.? I got one off ebay, and I thought it was kind of expensive, but it did work with the 4207 terminal. What I didn't understand was a fascination with the black mechanical Cherry switches the keyboard used.? These turn out to be extremely popular with the 'gaming' community.? I don't know if the tektronix keyboard can be used with a modern PC, I haven't looked at the interface signals yet.? The modern PS/2 keyboard has a clock and data line, the DEC LK201 used rs232, so what Tektronix used is anybody's guess.

5 years, 8 months

%20 nonsense

by jlw＠jlw.com

> whats with the weird tag on this thread? Oops, sorry. Clicking on an address in the mailing list viewed as a web page via http://www.classiccmp.org/pipermail/cctech/2019-April tries to fire up MacOS X Mail, which I don't want because I use Thunderbird.? So I "Copy Email Address" and paste it into a Thunderbird compose window To: field, and it has cctech at classiccmp.org?Subject=Re:%20'd_subject_line_mess&otherjunk.? I copied that into the Subject: line, and thought something would do the right thing with them upon receipt.? Oh well, there I go overestimating the intelligence of software again. -- Jeff Woolsey {{woolsey,jlw}@jlw,first.last@{gmail,jlw}}.com Nature abhors straight antennas, clean lenses, and empty storage. "Delete! Delete! OK!" -Dr. Bronner on disk space management Card-sorting, Joel. -Crow on solitaire

5 years, 8 months

Re: Storage for 1/2" open reel tape

by jlw＠jlw.com

> I've noted earlier that the vinyl "hanger strips" for 1/2" magnetic tape > have been degrading, becoming brittle and simply breaking away, > sometimes in small particles. I have about a hundred tapes from various contributors, and have noticed no age-related [1] deterioration of the seals, probably because mine don't get handled very much.? About 1/3 of mine have the vinyl hanger strips, another third the autoload seals, and the remainder are in the bulky canisters (with several different closures).? I also have a couple of tape racks (think "dish rack") that hold maybe thirty tapes, but the canisters are too thick to fit in. The tapes hang pretty well from the front lip of the wall-mounted wire shelves (that you can get at most big-box-home-stores) I installed not for that purpose. The thing is, I've read and photographed most of them, so I don't need [2] them anymore.? Their owners, like me, only wanted the data online, not the media back. Most museums have more than they want or can use, as well.? Some tapes have common-sense restrictions on redistribution (Personally Identifiable Information, I think they call it nowadays). I've even got some new, never-written ones.? But it pains me to trash them, so I'm open to suggestions. = [1] I have dropped and broken a couple of them, but that was due to insufficient age of the handler...? Some did not survive the reading process due to oxide-binder aging, but the seals are fine. [2] In many cases, usually by repurposing extra copies of software distribution tapes, the most recent data is shorter than the original, so the tails of older things past the EOF1 label and double tapemark can be read without much difficulty.? The thing is, I didn't figure this out until I'd been reading tapes a while, so the earlier ones may yield to re-examining. -- Jeff Woolsey {{woolsey,jlw}@jlw,first.last@{gmail,jlw}}.com Nature abhors straight antennas, clean lenses, and empty storage. "Delete! Delete! OK!" -Dr. Bronner on disk space management Card-sorting, Joel. -Crow on solitaire

5 years, 8 months

Sticking RL02 positioner

by charlesmorris800＠centurytel.net

One of my RL02 drives (that sat for a long time) has developed what appears to be a sticky head positioner. But it's only a problem going from the full-retracted position to loading track 0. Once it's loaded, the drive will pass all seek and read/write tests. It takes a surprising (to me) amount of force to pull the heads out into the disk area (power off, no pack). When they're out there, the arm slides back and forth easily. Sometimes it won't load at all - push the load button, light goes out, disk spins up to what sounds like normal speed, but the heads never move and the Ready light doesn't come on. There's supposed to be a Fault after 40 secs but that doesn't happen - it'll sit there forever spinning but not ready. If I turn off the power and remove the pack, and pull the positioner out just enough to avoid opening the Heads Home microswitch (which causes a Fault light), then it'll spin up, load track 0, and work fine the rest of the day. The manual (as usual) only recommends replacing the bad assembly for ease in field servicing, which is deliberate. But I don't have a DEC repairman and a warehouse full of parts handy... Is there some kind of adjustment or lubrication I can do? If I replace the positioner then I have to realign the heads (not too bad a job on this drive, though). Any ideas? thanks Charles

5 years, 8 months

Storage for 1/2" open reel tape

by cclist＠sydex.com

I've noted earlier that the vinyl "hanger strips" for 1/2" magnetic tape have been degrading, becoming brittle and simply breaking away, sometimes in small particles. So I set off looking for a low-cost substitute--any hangers that I could rustle up would probably be on their last legs at this late date. I hit on the idea of using 16mm move film plastic "cans". Much to my surprise, I found that there is still an active market for these things. After getting a few samples, I've discovered that the 800' cans fit a 10.5" reel (virtually all of the tape that I get) quite well. I'm not yet finished evaluating samples, but here's a photo of a can from Tuscan Corporation holding a reel of tape: https://i.imgur.com/KPKg75s.jpg The cans are vented, so not hermetically sealed. In the case of film, this is apparently done intentionally, as the acetate base of older film outgasses acetic acid, which only hastens degradation. If anyone's interested, I'll continue to post updates. I've got some >from Larry Urbanski coming in Monday. Larry seems to have the lowest price on these--about $5.75 each. --Chuck

5 years, 8 months

Game of Life for PDP-8

by kylevowen＠gmail.com

Back at VCF PNW, the subject of the Game of Life came up among some peers. I recall messing with the BASIC version that supported 32 by 32 cells, and there's also a FOCAL version that can do a whopping 11 by 11 cells. This was simply not enough. So, I wrote my own implementation and came to the realization of why more cells may not actually be better...it's freaking slow! https://github.com/drovak/pdp8life I've improved the performance a bit using some caching and other tricks to skip extraneous processing and twiddling of bits, but running in SimH for lots of cellular life still takes a while. I haven't been able yet to try it on the real hardware, and I can't say I'm looking forward to the speed of the real machine either! I'm working on a few new versions, which may get wrapped up into some conditional assembly soon. One version will support both storage and non-storage oscilloscopes with a VC8E. Another version may work to actually reduce the size of the bitmap to increase speed; it's all a tradeoff, I suppose. Would love to hear some comments if anyone plays with this. And, if someone significantly speeds things up while keeping the large playing field, I'll be very happy to hear how! Kyle

5 years, 8 months

IBM 360? on eBay.de

by u.tagge＠gmx.de

I'm not affiliated with the seller. https://www.ebay.de/itm/seltene-Anlage-Puma-Computer-IBM-2020/202646831828?…

5 years, 8 months

More stuff looking for a good home

by bill.gunshannon＠hotmail.com

Here's a list of some more stuff if anyone is interested in making reasonable offers. Probably the last I will have before my demise when my wife will likely send everything that's left to the skip. MODULE Description QTY NUMBER M9202 UNIBUS connector 3 M9302 UNIBUS TERM 2 ADAC 1632TTL 3 ADAC 1616/32HCO 1 Plessey Peripherals 703185-100C & 701877-100 with Cable 1 Data Translation DT2769/EP057 REV F 1 Data Translation DT2769/EP057 REV J 1 Data Translation DT15150/EP075 Dual D/A Converter Module M3106 4 Line Async Mux 1 M3106 4 Line Async Mux (w/broken handle) 1 M9060 LOAD MODULE 1 M8017-AA Async Line Interface 1 M8017 Async Line Interface (w/broken handle and berg socket) 1 G7273 NPG AND BUS GRANT CONTINUITY 5 RL Disk Drive Terminators 4 MV-II Function Select / SLU Module 1 A few modules that I ecpect are rare but of limited interest. Terak 8510 Memory and Video module w/bulkhead connector 1 Terak 8510 Floppy Module w/bulkhead connector 2 Terak 8510 Floppy Module wo/bulkhead connector 2 Terak 8510 RS-232 Serial Module w/bulkhead connector 4 Terak 8510 RS-232 bulkhead connectors 3 Terak 8510 Video bulkhead connectors 2 Condition of the Terak Modules can not be verified. They were functional at the time they were removed but I no longer have any functional Teraks to test them. Shipping would be the smallest size USPS "If it fits it ships" box so you can plan accordingly. bill

5 years, 8 months

VCF PNW 2019: Photos and Survey. Please?

by couryhouse＠aol.com

a pity there are not? name? captions? ? ?for? those of? us that? do? not? travel? well to be? these in person. Great photo? collection though!? Ed# In a message dated 3/31/2019 8:46:29 AM US Mountain Standard Time, cctalk at classiccmp.org writes: One last spam from VCF PNW 2019 ... Send us your Photos!? We want to put together a shared photo album so thatpeople can see the event from different perspectives.? It's a Google Photosalbum, so if you are a Google Photos user sharing is easy.? If you are nota Google Photos user or you have concerns/questions please let me know andI'll work out an alternative. The shared album can be found at:https://photos.app.goo.gl/e2rzk4iT4aHrQUoy6 Help us make VCF events better!? If you were at the event last weekend Ihave a quick survey that I'd like you to fill out.? The survey will help usshape future events.? The survey is anonymous; we are not collecting emailaddresses unless you want to get a chance at a free t-shirt.? (And eventhen, we are only using the email address for that single purpose.) The survey link is: https://goo.gl/forms/V3DiyxwkpbIOCKn73 Direct feedback by email also works well. Thanks,Mikemichael at vcfed.org or mbbrutman at brutman.com

5 years, 8 months

Yes there is a PDP 10 front panel and Kenbak on Ebay

by jnc＠mercury.lcs.mit.edu

> From: Guy Dunphy > What I want to know is, how do front panels of historic computers so > often get separated from the rest of the computer? I suspect it probably happened a while back, before the start of the vintage computer movement; you need to look at the decisions from the perspective of back then. (As an example, back then, I was offered the complete PDP-11/45 of my old group. I was up to my neck in contemporary, important, alligators - I was on the IESG of the IETF at the time - and didn't have the time to deal with saving it and moving it to my house; so I let it go - a loss I regret terribly now.) Here's what probably happened: the machines were about to be scrapped, and saving the whole machine wasn't practical - often, in part, because those machines were _huge_. (The CPU _alone_ of a KA10 would fill an entire room of a normal house.) So, one has a limit to what one can do. So the choice is to save the front panel alone... or to save nothing. Noel

5 years, 8 months

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test-drb April 2019