The Smell of Molten Projects in the Morning

Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

Category: Home Ec

Things around the home & hearth

  • HP-48GX Calculator Disassembly: Case Rivets

    The keyboard on my trusty HP 48GX calculator finally deteriorated to the point of unusability, so I tore the thing apart following the useful instructions there. The warning about applying force to the rivets that hold the case halves together gives you not the faintest concept of how much force is actually required to pry the mumble thing apart at the battery compartment; I finally invoked force majeure with a chisel scraper…

    HP-48GX case rivets
    HP-48GX case rivets

    I expected the calculator would not survive this operation and I wasn’t disappointed.

    An HP 50g is now in hand. Here in late 2011 I’d expect HP’s top-of-the-line RPN calculator to sport a crisp high-resolution display, but noooo the low-contrast 131×80 LCD seems teleported directly from the latter part of the last millennium. The manuals are PDFs, which is OK, but their content is far inferior to the HP 48GX manuals. In particular, the editing / proofreading is terrible. I infer that the HP calculator division can barely fog a mirror and is on advanced life support; HP’s diverting all their money to, uh, executive buyouts or some other non-productive purpose.

    The fact that HP sells new-manufacture HP 15C calculators doesn’t crank my tractor, even though I lived and died by one for many years. A one-line 7-segment display doesn’t cut it any more, even if the new machinery inside allegedly runs like a bat out of hell.

    My HP 16C, now, that one you’ll pry out of my cold, dead hands. At one point in the dim past, I’d programmed the Mandelbrot iteration into it to provide bit-for-bit verification of the 8051 firmware for the Mandelbrot Engine array processor I did for Circuit Cellar: slow, but perfect. That calculator has a low duty cycle these days, but when I need it, I need it bad.

  • Apple Season

    Our neighbor’s back yard features an unkempt apple tree about 3 feet from the fence that must be 40 feet high by now. It grows Macintosh-style fruit and drops half of them into our yard. Most land in the garden, some land in the yard, a few bounce off his plastic storage shed with resounding bonks, and every critter out there loves them. Mary makes applesauce from the best of the harvest and tosses the rest far away to keep the wasps out of her veggies.

    The chipmunks and groundhogs have a belly-busting good time:

    Chipmunk with apple
    Chipmunk with apple

    The deer, of course, eat ’em like candy, another reason for clearing the garden.

  • The Embedded PC’s ISA Bus: Firmware, Gadgets, and Practical Tricks — Unleashed

    ISA Bus Book - Front Cover
    ISA Bus Book – Front Cover

    A long time ago, in a universe far away, I wrote a book that (barely) catapulted me into the ranks of the thousandaires. Time passes, companies get sold / fail / merge / get bought, and eventually the final owners decided to remainder the book; the last royalty check I recall was for $2.88.

    Anyhow, now that it’s discontinued and just as dead as the ISA bus, I own the copyright again and can do this:

    They’re both ZIP files, disguised as ODT files so WordPress will handle them. Just rename them to get rid of the ODT extension, unzip, and you’re good to go. Note, however, that I do retain the copyright, so if you (intend to) make money off them, be sure to tell me how that works for you.

    The big ZIP has the original pages laid out for printing, crop marks and all, so this is not as wonderful a deal as it might first appear. The little ZIP has the files from the diskette, which was unreadable right from the start.

    Words cannot begin to describe how ugly that front cover really is, but Steve’s encomium still makes me smile.

    The text and layout is firmly locked inside Adobe Framemaker files, where it may sleep soundly forever. The only way I can imagine to get it back into editable form would be to install Windows 98 in a VM, install Framemaker, load up the original files, and export them into some non-proprietary format. Yeah, like that would work, even if I had the motivation.

    If you prefer a dead-tree version, they’re dirt cheap from the usual used-book sources. Search for ISBN 1-57398-017-X (yes, X) and you’ll get pretty close.

    Or, seeing as how I just touched the carton of books I’ve been toting all these years, send me $25 (I’m easy to find; if all else fails, look up my amateur callsign in the FCC database) and get an autographed copy direct from the source. Who knows? It might be worth something some day…

    The back cover has some useful info:

    ISA Bus Book - Back Cover
    ISA Bus Book – Back Cover

  • Shower Faucet Handle Tightening

    Some years back I replaced the shower stall faucets; they’d lasted about half a century, which is good enough. The new faucets were American Standard Cadet/Colony (their choice of name, the current Colony valves seem similar) with a nice, smooth exterior. Of late, both handles had become slightly loose and I finally got around to tightening them.

    Shower faucet valve stem
    Shower faucet valve stem

    The handle setscrews accept a 5/64 inch hex key and pop easily off the stems, revealing the splined plastic (noncorrosive!) mount on the valve stem. The Philips screw in that is what’s loose and allows the whole handle to wiggle just a bit; tightening the setscrew doesn’t help.

    Of course, tightening the screw in the cold water stem tends to open the valve, so you must firmly wedge the splined mount. I’m sure there’s a special wrench for that, but I just held it tightly; next time I’ll try a strap wrench.

    One would ordinarily dose the screws with threadlocker, so as to never have to endure this dance again, but these screws have coarse threads that engage another plastic doodad that engages two wings on the splined mount. So I guess I must retighten them twice a decade or so.

    The handle interiors sport a bit of corrosion (which does not respond to vinegar, so it’s not hard water mineralization), but nothing terrible. The setscrew, mirabile dictu, seems to be stainless steel…

    Shower faucet handle - splines
    Shower faucet handle – splines

  • Corelle Fragments

    I fumble-fingered a plate, it fell between my tummy and the counter, and hit the floor edge-on. There’s a lot of energy stored in that stretched-glass ceramic layer! [Update: The glass is under compression.]

    Shattered Corelle plate on floor
    Shattered Corelle plate on floor

    The fragments tend to be slivers rather than chunks, all with better-than-razor-sharp edges:

    Corelle slivers
    Corelle slivers

    A bit more detail on Corelle in that post…

  • Toyota Sienna Bank 1 Oxygen Sensor: Replacement Thereof

    So there we were, on our way to the Dutchess County Fair when I noticed the Check Engine light glowing beyond my right hand on the dashboard. We decided to not stop at the fair, drove through Rhinebeck, and returned home without turning the engine off.

    The last time that light came on, my Shop Assistant and I were on our way to Cabin Fever in York PA one Friday afternoon in mid-January. The Mass Air Flow Sensor had just failed, rendering the car un-driveable: the engine ran so poorly we barely got off I-81 to drift into a parking lot. Although the local Toyota dealer was just across the road, I replaced that sensor on Monday morning in the Autozone parking lot, half a mile down the road, at 19 °F in a stiff wind with inadequate tools; said Toyota dealer being useless like tits on a bull during the entire weekend.

    After the obligatory research, I put the van up on jack stands, crawled underneath, and discovered that the Bank 1 Oxygen Sensor lies behind & below the transverse-and-rotated engine, directly above and front of the chassis cross-support strut, where it cannot be seen or touched from any position. That’s why there are no pictures: there was no room for a camera and nothing to see.

    I had to buy a 3/8 inch breaker bar, as the sensor position lacked clearance for a socket wrench, a U-joint, a T-handle, or a step-down adapter from my 1/2 breaker bar behind the special 22 mm Oxygen Sensor Socket. I eventually got the sensor loose and unscrewed it one painful eighth of a turn at a time, with the exhaust pipe preventing a full 1/4 turn, removing and reseating the breaker bar with my fingertips for every single one of those increments.

    I deleted all over Toyota’s censored for quite some time thereafter…

    It’s been a couple of weeks, the Check Engine light remains off, and I hereby declare victory.

  • Silica Gel Drying

    So it’s time for the whole pile of silica gel to go into the oven. The various packages suggested something around 12 hours at about 250 °F, so I set the oven timer for 11:59 and let it cook overnight:

    Assorted Silica Gels
    Assorted Silica Gels

    The granules in the trays go into sealed glass jars, where they will remain dry until needed. The assorted beads & kibble in the plates get bagged up and go in the fireproof safe along with the big bag in the front, where they ought to be good for maybe half a year. It’s a new safe, so we’ll see how that works out; I tucked a note with the weights inside the safe.

    I found a “sealed” plastic bucket of assorted packages that I’d dried and weighed a decade ago and then lost in the back of the shelf. It had gained 2 ounces, but the packages have rotted out and the beads weren’t in good shape; they were the consumer-grade bags that aren’t intended to be dried and reused.