Re: Flip-Chip selloff (Al Kossow)
On 2021-02-03 5:36 p.m., Chris Zach via cctalk wrote: > Why don't we just use bitcoin? Thanks for the belly laugh
Re: OT: pints, pounds (Was: APL\360
On Mon, 1 Feb 2021 at 21:07, Fred Cisin via cctalk wrote: > > That is what it MEANS. > But, it's not quite right. It's off by about 4%. > A US pint of water weighs 1.043 pounds. > One "fluid ounce" (volume) of water weighs 1.043 ounces (weight)! Close enough for government work. With all the off-hand mental approximations people use to convert units, including some I think mentioned here, 4% is pretty good. I may use metric when I am measuring things myself, but I got my motorbike licence in 1991 and my car licence in 2005. I was solely taught and tested in MPH. For estimating stopping distances by eye, a metre is a yard, near enough -- and of course "car lengths" and seconds aren't affected. Keep 2 car lengths back under 30mph, and over that, maintain 2 seconds' braking distance, is metric-independent. > How much do you suppose a "pint" of ice cream weighs? Wouldn't know. I have never in my life seen such a unit on sale, I think. > And, not all beer has the same specific gravity. Alcohol is less dense > than water. > And, of course, further variation with temperature and atmospheric > pressure. Indeed so. It does get worse. When I emigrated, I had no problem adapting to buying half litres of beer -- or even, just once in a brewery in Slovakia, a litre of beer. But the strengths...! Czech beer comes in 10º, 11º, or 12º, and very occasionally 13º, 14º or even 17º-18º. I have almost never seen anything stronger. But what the heck is a ten-degree beer?! I'd never heard of degrees in beer before. Degrees proof, yes, but just halve that for %ABV, which is far more meaningful for me. But while a 10º beer being 5% alcohol by volume was just about believable, a 15% ABV beer seems unlikely. Well, it is. The system is "degrees Plato", a system so obscure there isn't even a Wikipedia page for it. And all I knew about Plato's drinking habits was: « Plato, they say, could stick it away Half a crate of whiskey every day » It's horribly complicated in use: http://8degreesplato.com/2017/05/31/so-what-is-degrees-plato/ No wonder nobody much outside Central Europe uses it. But this country is the world capital of beer -- they consume more per capita than anyone else. There are good reasons I like it here, and it's not the language. https://news.expats.cz/czech-food-drink/the-czech-republic-leads-all-nations-in-beer-consumption-per-capita-by-a-whopping-78/ The USA drinks 12x as much in total -- but has nearly 40x as many people. > And, if you are in England, > "A pint of water weighs a pound and a quarter." I believe I have heard that. Maybe this is why it is meaningless to me -- it doesn't work with UK Imperial units, only with American Imperial units. Yet more reason to burn imperial measurements in a fire and throw the ashes in the sea. > Despite very minor variances in gravity, Earth is MOSTLY HARMLESS. ;-) Did you know that the Central African Republic covers one of the largest magnetic anomalies in the world? It's so big it's named after the capital of the CAR, which will of course make it trivial for you all to look it up. > Instead, it just means that British pubs are not as stingy with their > beer. And, it doesn't need to be chilled to almost frozen to make it > drinkable. Very true. British beer is often served with very little foam on top, so the capacity of the glass is measured to the brim. A Czech beer without at least a few centimetres of foam is considered defective and most drinkers would send it back -- so Czech beer glasses are lined instead, to leave plenty of space for the froth on top. > I wish that there were a pub open. Oh gods, me too. > But, "The Albatross" (pub in Berkeley) > has closed down. forever. Can't stay in business with a lockdown. Sorry to hear that. > I can get beer delivered! Coincidentally, it is Corona beer! Oh my word. My deepest condolences. -- Liam Proven – Profile: https://about.me/liamproven Email: lpro...@cix.co.uk – gMail/gTalk/gHangouts: lpro...@gmail.com Twitter/Facebook/LinkedIn/Flickr: lproven – Skype: liamproven UK: +44 7939-087884 – ČR (+ WhatsApp/Telegram/Signal): +420 702 829 053
Re: PDP-11/70 debugging advice
> On Feb 3, 2021, at 8:07 PM, Josh Dersch wrote: > Sure enough, TIGB XTAL H was a flat line. Nothing happening at the crystal > itself either. The crystal's casing was fairly corroded (which is > interesting, since nothing else on the board is) and after a tiny bit of > prodding one of the legs fell off, so I'm hoping that's the culprit. Ah. One of the switches on the KM11 should enable the machine to run off the separate RC maintenance clock on the TIG, if you want to keep going before your new crystal shows up.
Re: HP Journal back issues
Thanks! The radio site aside from using low bit rate scan also I think compresses the pdf files. Ed# On Wednesday, February 3, 2021 J. David Bryan via cctech wrote: On Wednesday, February 3, 2021 at 9:25, ED SHARPE via cctech wrote: > Indeed this site is great for reference but alas are too lo-res for good > museum display images. They appear to be scanned at 150 dpi. The ones here are scanned at 300 dpi: http://hparchive.com/hp_journals -- Dave
ebay Payments WAS RE: Flip-Chip selloff (Al Kossow)
> I remember how annoying it was when Ebay required all payments through > paypal. I preferred checks and getting all the money. I am sure as a seller you liked it. As a buyer I wasn't about to send you a check for more than a couple of bucks without assurances (and no the FB system did not provide that). Let's be honest more stuff is selling, and for higher amounts, because of the ebay changes (CC only, money back guarantee, etc.). You can still get paid in cash or check by selling locally if you really prefer that. > Why don't we just use bitcoin? Because then inflation would go through the roof. Imagine you had paid one bitcoin ten years ago for a system. That would have been $2 (11/2011 price) Now with the change in price of bitcoin that coin is worth $37,046. Are you willing to sell your system to another buyer for $2 or even a $100? After all that system just cost you $37,044. Some people will not see it that way but most people will and want their money back plus interest -Ali
R: Winchester SA1004 file recovering
I wish apologize me. the work was done by a dear friend and I had mistakenly understood that he had used the Fluxengine card instead he used this card http://www.pdp8online.com/mfm/ with add-on daughter card interfacing with the SASI controller SA-1403. Since, despite repeated readings, we are not able to correctly extract the data from the second Winchester Hard Disk, we will probably operate by trying to rely on someone able to intervene on the platters of the SA-1004 Hard Disk, hoping to be able to recover as much as possible. Enrico -Messaggio originale- Da: cctech [mailto:cctech-boun...@classiccmp.org] Per conto di David Gesswein via cctech Inviato: giovedì 4 febbraio 2021 01:45 A: cct...@classiccmp.org Oggetto: Re: Winchester SA1004 file recovering On Wed, Feb 03, 2021 at 10:43:48AM +0100, Enrico email.it wrote: > > > A very dear friend first read in raw mode a 10MB Winchester hard disk model > Shugard SA1004 from which the files were correctly extracted and then set up > a test bench from which you can see in this video the complete system > operating with the HD ed il controller Shugart SASI SA1403: > https://www.dropbox.com/s/d9iacfgrnexso3o/GP%20T20%20con%20HD%20banco%20prov > a.mp4?dl=0 > > Despite we having attempted different readings (even using cards from the > first hard disk), using the same FLUXengine card > (http://cowlark.com/fluxengine/doc/building.html) the raw file still does > not present the Hard Disk directory, instead we read the information of the > files present but there may be bad bytes in these files and in the rest of > the disk as well. > I have only heard of FLUXengine being used for floppies. Can it handle hard drives? I hadn't heard of other boards that can read MFM hard drives other than mine http://www.pdp8online.com/mfm/. Other than the drive being faulty the biggest reason reading fails is the heads are no longer on track. You can tell that by looking at a histogram of the flux transition timing for a track. If they show peaks with good nulls between them the data is likely recoverable. If they don't you have to do something to shift the head position. Example histogram from by unit for ST506 type drive. https://groups.google.com/g/mfm-discuss/c/kjKez8vfapU/m/4XamyQJgCAAJ The SA1004 is a stepper drive. Some people have had success on other stepper drives with putting some rotation force or drag on the stepper to shift the heads. Creating a microstepper driver would give better control. May be able to say more if you provide more information on what you have done and checked to try to recover the contents.
Re: PDP-11/70 debugging advice
On Thu, Feb 4, 2021 at 10:19 AM Fritz Mueller via cctalk < cctalk@classiccmp.org> wrote: > > > > On Feb 3, 2021, at 8:07 PM, Josh Dersch wrote: > > Sure enough, TIGB XTAL H was a flat line. Nothing happening at the > crystal itself either. The crystal's casing was fairly corroded (which is > interesting, since nothing else on the board is) and after a tiny bit of > prodding one of the legs fell off, so I'm hoping that's the culprit. > > Ah. One of the switches on the KM11 should enable the machine to run off > the separate RC maintenance clock on the TIG, if you want to keep going > before your new crystal shows up. Yeah, you'd think... but it doesn't work :). I mentioned earlier in this thread that it's stuck in single-step mode. From the schematics it looks like the crystal clock needs to be running to clock some of the flip flops used in the "Source Synchronizer" to select the proper clock source. My guess is that since the clock isn't running, the flip flops are left in a weird state. Or there's another problem here unrelated to the crystal clock. I guess I'll see in a day or so. - Josh
Re: PDP-11/70 debugging advice
> On Feb 4, 2021, at 1:51 PM, Josh Dersch wrote: > [RC maintenance clock] Yeah, you'd think... but it doesn't work :). I > mentioned earlier in this thread that it's stuck in single-step mode. From > the schematics it looks like the crystal clock needs to be running to clock > some of the flip flops used in the "Source Synchronizer" to select the proper > clock source. My guess is that since the clock isn't running, the flip flops > are left in a weird state. Oh, interesting! Noted for future reference. The TIG is not exactly straightforward...
PRIVATE: OT: pints, pounds (Was: APL\360
I may use metric when I am measuring things myself, but I got my motorbike licence in 1991 and my car licence in 2005. I was solely taught and tested in MPH. For estimating stopping distances by eye, a metre is a yard, near enough -- and of course "car lengths" and seconds aren't affected. Keep 2 car lengths back under 30mph, and over that, maintain 2 seconds' braking distance, is metric-independent. But, none of those are accurate for the physics. Can an Isetta follow much closer than a Cadillac? I don't have an Isetta. I'd like one. I'd love to get the Micro-Lino (a current Swiss electric replica of an Isetta), but they don't plan to export to USA. Stopping distance is also certainly not a constant of 2 seconds, even if talking about both vehicles making a panic stop. My current car (a Prius "Prime") can stop in significantly less distance than my early VWs did. In a panic stop, a VW 2 seconds behind me would plow right into me. How much do you suppose a "pint" of ice cream weighs? Wouldn't know. I have never in my life seen such a unit on sale, I think. Ice Cream used to be sold in 1/2 gallon. The half gallon container has been reduced to "1.5 quarts/1.41L". "The reduction in size is to avoid raising the price" (which went up ALSO) Half gallon carton of milk (64 fluid oz) is now a 54 oz carton. Tiny cartons of ice cream exit, and used to be called "Pints": 16 fluid oz/473ml DELIVERY of ice cream is pretty risky; good if you are one of the first stops of the delivery, . . . Yet more reason to burn imperial measurements in a fire and throw the ashes in the sea. YES Despite very minor variances in gravity, Earth is MOSTLY HARMLESS. ;-) DNA once told aspiring writers, "Never blow up the planet in the first chapter; you are likely to find that you need it later." Did you know that the Central African Republic covers one of the largest magnetic anomalies in the world? It's so big it's named after the capital of the CAR, which will of course make it trivial for you all to look it up. Interesting. And never noticed until 1950? I can get beer delivered! Coincidentally, it is Corona beer! Oh my word. My deepest condolences. It's a Mexican American beer. I drink very little. If I were a drnker, I'd have to find something else. -- Grumpy Ol' Fred ci...@xenosoft.com
APOLOGIES; was not meant to be to the list (Was: PRIVATE: OT: pints, pounds (Was: APL\360
Sorry about that. I didn't pay close enough attention to my outgoing header.
UDS EIA module for ASR33
Recently acquired an ASR33 with an old EIA (RS-232) Interface convertor module. It came with a two page spec and cable pinout sheet that is more hole than it is paper. Manufacturer is United Data Services (UDS) in Phoenix. Model seems to be 312 A 0568 (might be 0563) Google hasn't been much help and Bitsavers is silent as well.. Herb Johnson of Retrocomputing.com has 312 A 0567 which appears similar but not close enough to be useful. Anyone familiar with this unit who could share docs? (willing to scan and share if desired) Steve
Re: PDP-11/70 debugging advice
On Thu, Feb 4, 2021 at 2:42 PM Fritz Mueller via cctalk < cctalk@classiccmp.org> wrote: > > > On Feb 4, 2021, at 1:51 PM, Josh Dersch wrote: > > [RC maintenance clock] Yeah, you'd think... but it doesn't work :). I > mentioned earlier in this thread that it's stuck in single-step mode. From > the schematics it looks like the crystal clock needs to be running to clock > some of the flip flops used in the "Source Synchronizer" to select the > proper clock source. My guess is that since the clock isn't running, the > flip flops are left in a weird state. > > Oh, interesting! Noted for future reference. The TIG is not exactly > straightforward... So I realized today that, hey, I have a burned-out 11/45 in the garage, and it has a TIG (albeit an M8109), and it also has a 33.33Mhz crystal on it. And because I'm impatient and can't wait for my Digi-Key order to come in, I went out and borrowed the crystal from the 11/45's TIG and installed it in the 11/70's. The 11/70 is now somewhat operable. I can examine and deposit memory, at least for a short while -- after the system warms up for 30 seconds or so the Load Address switch stops functioning. (Happens gradually, too... for 10 seconds or so it works every other time you toggle it, then it stops entirely.) Everything else seems to work properly after this happens, so I'm kind of curious if there's an IC on the front panel that's gone bad, though I suppose it's still completely possible it's something on the CPU end. I'll have to do some debugging, but it'll have to wait until this weekend. As an aside... The M8109 is very similar looking to the M8139... any ideas what the functional differences are? There seems to be an extra IC and some ECO wiring on the M8139. I'll have to take a closer look someday. - Josh
