Wednesday January 23, 2008

Overcoming Blog Inertia

The past two years have seen a great deal of change in my life, mostly centered on the arrival of my two children.  My son Timothy was born in 2005 and is now a very verbal two year old.  My daughter Kathryn was born just this November and has recently started to sleep through the night and smile.  There are so many cliche things to observe about becoming a parent, but they are so true.  Just when I think I could never be prouder, never be more tired or love them more; it turns out I am very wrong.

Monday April 04, 2005

Confessions of a Keyboard Snob

I love loud crunchy clicky keyboards. First keyboard I can remember using was an Apple ][ and it had a loud crunchy keyboard. You knew you were typing because you could hear the joyous cacaphony. Life has since provided a cavalcade of keyboards, some not as good as others. Recently I was forced to give up my favorite keyboard ( an IBM bazillion-key monstrosity manufactured in 1993 ) and embark on an epic tale of discovery, disappointment and technolust. And who said being a geek isn't saucy?

Ode To A Keyboard

In no particular order, my favorite keyboards down through the ages have been:

1. IBM RS/6000 105 Key keyboard
2. Apple Extended Keyboard II
3. NeXT second generation keyboard with the pipe in the right place.

OK, I fibbed about order. The IBM was really my favorite and I went to great lengths to keep using it. We first met as a co-op at IBM and it wasn't quite love at first touch. I had just come off a recent relationship with an Apple Extended Keyboard II ( the kind that shipped with the early generations of MacIntosh IIs ) and I was still pining for that beauty. The IBM quickly woo'ed me though with its springy keys and satisfying clickiness. As an employee, I bought several of these keyboards at the IBM Employee store ( alas, an era gone by ) for a couple of dollars a piece. When I joined Sun, I went to heroic efforts to keep my keyboard of choice. I wasn't kidding about heroic. The dongle for hooking up PS/2 style devices to Sun hardware was not cheap ( Thanks boss! ) and Stop-A was a hideous production involving an auxillary keyboard kept under the desk.

As I mentioned, I also had a fling with the Apple Extended Keyboard II. A fine keyboard with a somewhat softer touch than the IBM, but a satisfying type regardless. I often found myself thinking about this keyboard, but given it's strictly ADB implementation and my Apple sticker shock it seemed we would never meet again.

Through the Desert to An Oasis

Circumstances beyond my control required that I give up my trusty keyboard companion and find a new pointboard to ride the crystal wind with. I'm not sure how many cyberpunk metaphors I just fractured, but I do know that I hate Sun Type 6 keyboards with a hot seething undying hate which brooks no argument. They are too mushy and the layout is abominal. Apologists will point to the PC style Type 6 and I will laugh the laugh of the righteous. Sun Type 6 keyboards are icky and I don't want to use one. You can't make me.

So I tried to use the USB keyboard that came with my Sony Playstation 2 Linux kit. It was relatively crunchy but still the touch was not anywhere close to my beloved IBM. I tried to use the Sony for a couple of months, but my accuracy suffered from the poor feedback of it's mushy keys. I wanted my noisy clicky crunchy keyboard back.

With the help of Google, I began searching for my next keyboard love. Long story short, I found the Matias Tactile Pro keyboard. It is a revival of the Apple Extended Keyboard II updated for our modern times. You can google up several glowing reviews of the Tactile Pro which talk about it's style and manufacture. What you need to know is that it is clicky crunchy and glorious! These keyboards aren't cheap and it took alot of typing on crappy keyboards for me to gather my courage and order one sight unseen. I'm so glad I did, it was love at first type!

I'll miss you my old IBM friend. But I, for one, welcome our new keyboard overlords.

-ejo

(2005-04-04 12:46:48.0) Permalink Comments [3]

Monday January 10, 2005

LASIK Surgery

Two years ago, after a great deal of introspection and research, I decided to undergo LASIK surgery. I was 34 at the time and I had worn glasses for the vast majority of my life. My vision was 20/600, which means I could see at 20 feet what most people could see at 600 feet. I was very nearsighted. Without glasses I was unable to read anything further than about 5 inches from my face. Today, my vision is 20/20 in both eyes and the wonder of living life without glasses has not worn off.

Deciding On LASIK

My optometrist and I had spoken about LASIK and other vision correction surgeries for close to five years. At first his knowledge of the surgeries was superficial and his advice was to wait for a few years. Later he advised me to wait until my eyes settled down since most reputable surgeons require a candidate's prescription to be stable for two years. That was four years ago. I started to read up on the procedures available and talking to people who had the surgeries.

Most of the people I talked to had either PRK or LASIK surgeries. Most reported similar experiences, with LASIK seeming to have shorter recovery times. My optometrist started performing patient screening for a local franchise of The Laser Center and began learning a great deal about LASIK. I spent a great deal of time researching on the web; reading about the various positive and negative outcomes.

Two and half years ago, during a routine exam, my optometrist announced that my eyes had been stable for two years and he thought that I might be a good candidate for LASIK. He recommended The Laser Center in Austin, mostly due to the fact that only one surgeron was performing operations there and his success rate was extremely impressive. I contacted The Laser Center and scheduled a battery of test to determine if I was indeed a good candidate.

Elective Refractive Surgery

I arrived at The Laser Center armed with a checklist of questions and a paper entitled "Ten Reasons Why You Should Not Have Eye Surgery" ( or something very close ). I would be making a majority of my decision to trust my eyes to these people based on their reaction to my questions. They were delighted that I had brought so many questions with me and we proceeded to spend over an hour going through each question. The people at The Laser Center were very forth coming and provided as much historical data on previous surgeries' results as were available ( three years ). Before the first test to determine my suitability for surgery, I was ready to trust these people.

Next came a battery of tests, the purpose of most I forget. The one that stands out in my memory produced a topographic map of my eyes. It measured the thickness of my corneas and the amount of variation seemed alarming until I noticed the key. The apparant hills and valleys were absurdly small features on my corneas and completely normal. The final verdict, my corneas were thick enough to make me a good candidate for surgery. Thin corneas might tear during the procedure which increases the amount of time required to heal dramatically and increases the possibility of infection. Thick is definitely better.

LASIK or Maybe I Shouldn't Have Asked

Excerpted from http://www.fda.gov/cdrh/lasik:

LASIK stands for Laser-Assisted In Situ Keratomileusis and is a procedure that permanently changes the shape of the cornea, the clear covering of the front of the eye, using an excimer laser. A knife, called a microkeratome, is used to cut a flap in the cornea. A hinge is left at one end of this flap. The flap is folded back revealing the stroma, the middlesection of the cornea. Pulses from a computer-controlled laser vaporize a portion of the stroma and the flap is replaced.

You can imagine that reading about it and experiencing it might be two very different things. And you'd be right.

My surgery was scheduled for 11:15 am on January 9th. My wife and my optometrist accompanyed me to the clinic. My wife was going to drive me home afterwards and my optometrist just plain kicked ass (he's semi-retired now, otherwise I'd be shouting his name to the rooftops). We got there early and spent about 20 minutes in the (posh) waiting room before I was taken to prep. Preperation involved taking a sedative, a final check by the staff eye doctor and a brief visit from the surgeon. The surgeon was brief but positive and then I was lead into a darkened room to wait my turn. There was quiet classical music playing and three other people in the room mellowing out with their sedatives. One by one we lead away to the operating suite. My optometrist came and got me and it was my turn.

Blurred Impressions of Something Scary

The sedative administered before the procedure is important because three very unnatural things are about to happen. I entered the surgical suite and was situated on a padded table with a cluster of vaguely industrial equipment around the head. Vaguely because I wasn't wearing my glasses at the time. They don't waste alot of time, and in very short order they began prepping my eyes by placing numbing drops in them and cleaning around my eyes. Because blinking can be disruptive during the procedure, they then insert a lid speculum into your eye ( this is addition to taping your eyelids open ). That is the first unnatural thing. Next a suction cup is attached to your eye to hold the eye still while the microkeratome is used to cut a flap in the cornea. That is very unnatural, but didn't hurt. The flap is then lifted and folded over in preperation for the laser. At this point, my vision was very blurry and I was directed to look directly into a small red light directly above me ( the aperature for laser ). The laser used in my procedure incorporated an eye tracker which provides feedback to the laser and will also shut the laser off if your eye moves too far out of axis.

Staring at the red dot, the surgeon announced that the eye tracker had locked on and the laser would be firing it's preprogrammed sequence for some number of seconds. I don't recall the exact number, but it was less than 60 seconds. During that time, the laser buzzed but I didn't notice any visual artifacts. I was struggling to look at the red light, terrified that I'd wreck my eyes by moving at the wrong time. I also had a vague impression of a burnt smell, which of course was the ablated tissue from my eye. The third unnatural thing.

The surgeon counted down the last few seconds and the laser shut off. He then inspected the work done by the laser and spent a great deal of time folding over and smoothing out the flap in my corena.

The first eye ( the right ) was done.

I was shaking like I was caught in a blizzard without a jacket. I had no idea how I would endure the left eye. The discomfort of the ligature and the fear of loosing my sight due to moving during the procedure were overpowering.

And then the coolest thing happened. My optometrist, who had accompanied me into the suite and observed everything so far, reached out and patted my foot and murmured a few words of encouragement. That's all. I felt a sense of relief that just flooded me. I can't explain it since I was defintely under the influence of the sedative, but I stopped shaking as much and the team went to work on my left eye. While uncomfortable, the left eye was no where near the ordeal that the right eye was.

Less than ten minutes in the suite and I was being led out. My doctor and the staff doctor examined my cornea flaps and gave care directions to my wife since I was still pretty shook up. I had antibiotic eye drops and steroid drops and lubricant drops and a pair of clear eye shields that I would need to wear for weeks ( to prevent me from touching or rubbing my eyes and disrupting the healing of the flaps in my corneas ).

On the car ride home, I was blurrily reading the roadside signs.

Without glasses.

Recovery

The first two weeks I was certain that I'd had a bad outcome and my anxiety during the procedure was the cause. But in reality my eyes were healing and my expectations hadn't been realistic. My vision was blurry but already far better than it had been without glasses. After two weeks, my vision was 20/20 in the right eye and 20/15 in the left. I would have good seeing days and bad seeing days, but I think those might have been related to the muscles around my eyes re-learning a lifetime of movement to accomodate my new accuity. My doctor was unable to explain the descrepency between my right and left eyes. We think the difference might have been induced by my anxiety during the right eye, but it's only a theory. We recommended back to the clinic that they review the amount and type of sedative given since I might not have received enough.

The two biggest post-procedure complaints most people have are dry eyes and haloing at night. The dry eyes stems from the nerves in the cornea which are severed when the flap is cut. Those nerves provide feedback when the eye became dry and take time to grow back. For the first six months afterwards I used eye lubrication three or more times a day. Two years later I don't have any need for supplimental lubrication.

Haloing ( or flaring ) at night happens when viewing a bright light ( such as oncoming headlights in traffic ). For me, the haloing is no worse than what I had experienced with contacts. There is an interesting retouched photos on Surgical Eyes which attempt to show what it's like to experience haloing. The photos are not representative of how I see at night; the halos I see are much less pronounced.

Two Years Later

It's been just over two years and I could not be happier. I can wear cheap $5 sunglasses and not worry if I loose them. I can SCUBA dive without worring about loosing contacts during a dive. My pistol and rifle shooting improved. I can read the clock across the room when I wake up in the morning. Practically every aspect of my life improved, including my self-esteem.

As I grow older I'm told I will become farsighted and will require reading glasses. Until then I should enjoy 30 or more years of good vision. I think I can live with that.

-ejo

(2005-01-10 14:02:02.0) Permalink Comments [1]

Monday November 15, 2004

Demolition Man

When we moved into our house five years ago, there were certain things that needed changing right away. The pink carpet throughout the bottom floor had to go, as well as the baby blue carpet upstairs. The previous owners refused to give us a flooring allowance, I guess they loved it or were colorblind. As soon as possible, we repainted and refloored as much as we could afford at any one time. The only original flooring left in the house is in the upstairs bathrooms and the utility room. And the day of reckoning will soon be at hand for them as well. Two bathrooms retain their original wallpaper; wallpapering the kitchen was an experience not soon forgotten or forgiven. And only the stairwell has escaped the roller.

But this isn't a story about carpeting or painting...

The Shed (aka Rat Hilton)

Our backyard isn't gigantic by most measures, but the dogs like it and there are some nice trees with good shade (very important when you consider Texas summers). The previous owners left behind a shed that at first blush seemed perfectly servicable. And so it was. Gardening tools and supplies all fit handily in it. I was honestly excited about it. We could keep lawn stuff in it and not in the garage ( where presumably the cars would go, oh how wrong I was about that ). Well, the shed turned out to be the most swingingest place in all of Rat Town. My most vivid memories of "Yuck!" are finding out what happens when you store something in the shed that rats might think is yummy, in this case a bag of grass seed. The rats shredded the bag and then proceeded to poop everywhere ( is grass seed a laxative? ). So after the fine feast, the rats decided that it would be a fine place to live and raise their young. I imagine a little rat Moses leading his rat clan through some sort of rat desert, one day finding our shed and saying to his rat people "Lo! I deliver unto you the place that was foretold! The SHED of PLENTY!".

The Great Rat War

Wanting to be a responsible homeowner, I launched an early offensive to throw the rats off balance and begin winning the hearts and minds of my neighbors. I tried all sorts of different bait and poison. But the rats were eating so well on other stuff that I only managed to kill off the dumb ones. I tried live trapping them, but mostly I caught rabbits, opposums, racoons and the occasional cat. I combed the shelves of the local farmer's co-op, looking for something that would end the rat menance. Nothing worked. My favorite rat remedy was the big sheet of super sticky paper, essentially fly paper for rats. I put this down in the likely areas one evening and barely surpressed my anticipatory chuckles of glee. Those rats would get stuck in the paper and finally I would begin making in-roads in reclaiming my shed. The next day when I came home from work to inspect the mayhem I had wrought upon the rats, I found instead that my dogs had stumbled into it and managed to get their paws glued to their heads. Note to self: dogs not so smart, rats smart.

Rats Win

So, I gave up. The rats won and the shed became a premier rat resort destination and I stopped storing things in the shed that I cared about. The shed spiraled into decline; the paint flaked and it began to rot. Of course, the rats loved it even more.

Ratageddon

Unbeknownst to me, the neighbors had inadvertantly implemented their own anti-rat campaign. It seems that Mrs. Neighbor had a soft spot for kitty cats, and decided to feed one of the feral population. Cats can't seem to keep a good thing to themselves, and before you could say "Meow" Mrs. Neighbor was running a tuna kitchen for every down on their luck feral cat in town ( or so it seemed ). But the tuna ran out (as it inevitably always does ), and the mob of ravenous beasts tuned into their latent instincts. They heard that tiny cat voice inside themselves that said "Kill everything you can find that's smaller than you and eat it." It turns out that canabalism among felines isn't as rare as you might think. They also managed to deplete the neighborhood supply of birds, although for some reason we still have tons of big stupid morning doves. Maybe the doves are smarter than I thought, or the cats were more descriminating. After the inital orgy of cat carnage, the city moved in and "relocated" a great deal of these cats to "greener pastures". Apparantly some kill-joy alerted the authorities that there were far too many cats rampaging in myour neck of the woods. The remainder of cats moved on, like some great ravening herd of cat locust. And the shed? It looked like the morning after of a giant rat party.

The New Shed Style

Like the great Eye of Sauron, my wife turns her attention to various parts of the house and environs which she deems not up to par and this leads to a list of honey-do's which I must dutifully ignore for as long as humanly possible. It's her fault really, she insisted that we leave out the "Obey" clause in our wedding vows and I take that sort of thing very seriously. Last spring, the shed came under her baleful glare and she decreed that a New Shed must be found. And found it was. We put down some cash and set a tenative delivery date of September. It will be glorious! All metal construction with a pest proof 30 year warrantied fully treated wood platform base. Alaskalite translucent panels to transmit light into the spacious 10x12 foot interior graced with 2x4 studs, ready and willing to accept whatever sort of shelving or storage devices you might imagine. And tall! No more ducking to go in and out of the shed, I could stand tall and proud walking into my new shed. Of course there's a catch. The old shed must go.

Shed-Be-Gone

Last week, I received a phone call from the company supplying our new shed. The shed was ready for delivery and would Monday, November 15th at 10am be good for me? I paniced and said "Sure." What I really meant to say was, "I'd like to reschedule for next week to give me some time to get rid of the old shed." But you always think of those clever things just after you've hung up the phone. So this weekend, after procastinating more than half of a year, I tore down the shed. I had some help, my yard man offerred up his services as well as his very large trailer to move the ex-shed to the dump. We started promptly at 9am on Saturday morning, which was cold and grey. I fully expected the leaden skies to unleash a torrent of Noahianic proportions at any time.

We worked quickly, removing first the outer rotted skin of the shed. With the bones of the shed exposed, my yard man trotted out his secret demolition weapon: the Eight Pound Sledge. Now I'm not really up to speed on my demolition tools, so I did not understand the true wonder that is the Eight Pound Sledge until I took it up and swung it for the first time. Holy Crap! Four or five good swings at the four corners and the shed was ready to come down. IMPRESSIVE! With only part of the roof still intact, I pushed the shed over into a corner with little effort. It landed with a resounding "crash" and we swiftly dismembered the mouldering carcass. Ok, it took about 2 and half hours to get it all tore down and stowed on the trailer. A short drive to the nearest dump and another 20 minutes saw the shed stored for future generations of cultural anthropologists to find and dissect with stunning inaccuracy: "We think this structure was utilized by primative suburban dwellers in strange ritualistic events involving rats,cats and perhaps grass seed. Our best guess involves weekly fertility rites in the summer where the clan's primary acolyte would tend the lawn in hopes of gaining prestige in the community, conferring all manner of honor upon their clan."

Or it might be spot on.

Aftermath: Delivery Day

So today is November 15th, and yesterday I spent quality time in the backyard making sure that the chainlink fence facing the street ( we live on a corner ) was ready to be taken down. The plan was for the truck to drive up onto the lawn and drop the shed in-place. Of course the chainlink fence would impeed its' progress, so it had to come down. It turns out that it is pretty easy to disassemble a chainlink fence, as long as there isn't a giant array of creeping Morning Glory vines on it. Which ours did, past tense. I think they were an insideous plot by my wife, and not just "pretty" as she claims.

So, this morning I awake refreshed and rejuvanated with the sure knowledge that the new shed would be delivered today and thus begin a new era of prosperity in the backyard. That was, until I realized it was raining... still. Did I mention that it rained most of the weekend and all of the aforementioned toil occurred while being sodden? And cold?

The shed-angels call and say that they aren't going to deliver today since the truck will tear up my yard and possibly get stuck.

No shed today.

Maybe.. maybe. Maybe shed tomorrow. If the rain lets up.

-ejo

(2004-11-15 14:49:49.0) Permalink

Tuesday October 26, 2004

Underwater Salvage

This past weekend I helped my father-in-law's neighbors recover a couple of items lost in the (very) murky depths of Lake Buchanan. Lake Buchanan is just a few miles outside of Burnet, Texas and about an hour north and west of Austin. Buchanan is quite the fisherman's paradise, as long as said fisherman retains his favorite rod and reel.

Two weeks again, a fellow was night fishing in a boat just off a private dock which features an underwater light. By accident he managed to send his $250 Shimano reel overboard into about 14 feet of water. By all accounts, he spent the next couple of days dragging with a large treble hook and nets trying to recover his pricey bit of kit. No joy. By chance he ended up talking to my father-in-law about it, who mentioned that I dive and might be able to recover it for him. Who am I to disappoint my father-in-law?

The Afternoon Entertainment Arrives

The neighborhoods around Lake Buchanan are composed mostly of retired folks who know each other pretty well. Whether they like each other is a whole other post. So when I showed up in my frogman gear to recover a fishing pole, word spread quickly. Soon the shore was populated by people sitting in lawn chairs giving me a good natured ribbing ( something about "Sea Hunt" ). Speculation abounded on what I would encounter in the way of obstacles on the bottom, and there was considerable doubt that I would be able to locate the pole at all. For the most part, I was reasonably certain that I could find it given enough time. Since the water depth in the area of operation was relatively shallow ( less than 20 feet ), I would have over an hour of bottom time to get the job done.

Since I was diving solo, my main concern was entanglement. As mentioned above, Buchanan is a fisherman's paradise and I was worried about monofiliment, rope attached to anchors and tree limbs washed into the lake. I carried two knives ( a thigh sheathed 5 inch blunt tip and a short BC mounted chisel tip ) and a pair of EMT shears. Between the knives and the shears I was confident that I could hack my way out of most entanglements. If I did become entangled, plan A was to clear the entanglement with a knife or shear. Plan B was to take off my BC and clear the entanglement. Plan C was to ditch my gear and make for the surface doing a controlled emergency swimming assent (CESA) in the event that my gear entangled and I ran out of air. In general, I think that diving should be done with a buddy and solo diving should be avoided. In this particular case, I think a solo dive was appropriate ( clear goal, no overheads, shallow water, EMT trained personel on shore, lots of air and good gear ).

The hapless fisherman made an appearance to give me an idea of where his boat was when the incident occurred; approximately 20 feet off and 45 degrees to the left of the dock in question. He runs a business on the lake and wasn't able to stay and watch the operation, but promised a reward if I could recover the reel. Easy money, I thought.

Pea Soup

My confidence was significantly erroded when I got in the water ( which was a refreshing 78 degrees Farenheit ). When I stuck my face underwater I could barely see my fingers at arms length! And that was just at the surface without disturbing the bottom. This could very well be challenge. I took a compass heading off the corner of the dock, and swam out about 20 feet trailing a nylon rope that we'd tied to the dock. The idea was to use the rope as a reference underwater to help me quarter the search area.

I submerged and did a face first dive to the bottom. Most dive instructors won't encourage that sort of descent since a head down attitude makes it more difficult to equalize pressure in your sinuses, but my primary concern was to not hit the bottom and stir it up any more than necessary. Swimming down in that murk was pretty disorienting, and I was relieved when I finally saw the bottom at about 13 feet. The bottom was a jumble of small brush on top of a soft layer of leaves and mud. I worked on my bouancy for a couple of minutes to make sure I was as neutral as I could get and then started quartering.

Houston, We Have Murk.

Afterwards, my dive computer showed that I spent maybe 10 minutes underwater. But subjectively, it seemed to be forever. I had to stop and check my compass frequently since it was easy to become disoriented. The rope helped in guiding an arc thru the search area, but it is cumbersome to swim and hold on to a rope and check guages and check the compass. The bottom was covered in thickets of brush that had washed into the lake and collected around the limestone rocks which make up the shore. The pole had been submerged for two weeks, so it had plenty of time to take on the aspect of a algae covered tree branch. I spent alot of time inspecting brush piles looking for something metallic. On my second reverse in my quartering, I found it in a tangle of brush. I had been sort of combing through a pile with my hands ( gloves are good! ) when I noticed that one of the twigs I had just disturbed had an eyelet at the end! I worked the rod free of the brush and brought the reel up to my mask for inspection. I was worried that I'd just found somebody's Zebco 202 rather than the pricey Shimano I was after. Sure enough, the big open reel said Shimano on it!

Return the Conquering Hero

While You're Down There..

After proving my prowess at underwater salvage, the owner of the dock approached me and asked me if I would mind pulling something up for him. It seems that a two-seat gliding rocker had blown into the lake off the end of dock a couple of months ago. "Sure!" I said. Down I went, trailing my trusty 5-strand yellow nylon rope. I located it quickly in about 11 feet of water three feet off the end of the dock, and I secured the rope with a couple of half-hitches (about the only knot I can tie reliably anymore besides an axe knot). The crew on the dock waited until I surfaced and then hauled the thing up. The rocker was covered in algae, but surprisinginly it didn't seem to have rusted much at all. The owner of the rocker wasn't quite as generous as the fisherman, but I wasn't looking to make a buck off these folks either. It was fun for me and I was glad to help people at the same time.

I guess if this computer thing doesn't work out, I can always fall back on my mad underwater salvage skillz.

-ejo

(2004-10-26 12:55:27.0) Permalink Comments [1]

Tuesday October 05, 2004

Night Diving

Often times when I tell people we've been night diving in Lake Travis they respond with "how can you tell the difference?". Admittedly, visibility in Lake Travis is never on par with blue water which I'm told can be as great as 170 or more feet. Ok, nowhere near that. I think the best visibility I've experienced in Lake Travis has been somewhere around 15 to 20 feet. Still, diving in the daytime murk is somewhat different than diving in the same murk at night.

Vertigo Happens

Roy and I have been diving Windy Point on Wednesdays, nominally with the group from Scuba Land. We've been getting in the water around 7:30pm, which has been right around dusk. Decked out with green and red tank lights and an array of hand-held lights, we attempted dives similar in profile to our daytime dives.

Surprisingly, I didn't feel a great deal of anxiety of being in the water in the dark. I felt pretty confident in my equipment and my buddy, and just tried to enjoy the experience. Of course that all changed once the dive started. I was suprised to learn just how much I depended on visual cues that were either absent or far less prominent in the dark. Our percepetion of our current depth was always skewed too low ( we must be deep, it's dark ). And we also learned that navigation in the dark is somewhat difficult ( learned that a compass is not an optional piece of gear ), and that lights attached to your mask can become a dazzling hazard to your buddy.

So, vertigo. Experienced it for the first time on my first night dive. We were lost at 40 feet in a green haze of dusk, without a compass. Now we can normally navigate pretty well by following the contour of the shore, but we lost sight of the bottom whilst swimming about and got disoriented in the surrounding green. I didn't want to swim out into the lake since we'd heard some props earlier and boats are scary to divers. So our choices were surface or drop to the bottom or swim around lost some more. We went with c) swim around lost some more. I was looking down, hoping to see the bottom and get our bearings again when I started to notice the particulate in the water illuminated by my mask light. But I wasn't sure it was twack in the water, and thought it might be the bottom. And since I wanted it to be the bottom, I swam towards it to see if it was. And then I reached out to try to touch the bottom, and suddenly I'm in the grip of vertigo when my hand passes thru what I expect to be the bottom. As soon as it happened, I realized what happened and I remembered how to fix it. Find your buddy, hang on to him if you have to, and just look at him. Your brain sorts out what your middle ear and your eyes are telling you, and the vertigo subsides. So I find Roy, that was easy, and signal a problem and point to my head and give him hover signal. Sounds good, but I hadn't considered that by looking at Roy I would also blind him with my mask light and that about a third of my signals would get lost in the glare. Roy afterwards said he thought I was signaling a problem with his tank, and he kept reaching around his shoulder. We eventally got on the same page, and by that time the vertigo was under control. It then occurred to me to check my guages, and we had drifted up to about 20 feet from 40. Visual cues absent and the task load of the vertigo episode had kept us from keeping up with our depth. We dumped our BCs to get back to 40 feet and decided to swim off at a 90 degree to our previous imagined heading and eventually hit the shore contour and finished our dive.

Water temperatures are starting to drop, so there's no telling how many more night dives we'll get until spring ( or we shell out for better thermal protection ).

-ejo

(2004-10-05 12:08:19.0) Permalink

Tuesday September 14, 2004

Assault Weapon Ban Sunset

Despite what some media outlets are reporting, I can attest that I have yet to see one assault weapon toting maniac running unchecked in the streets ( and this is Texas! ).

For myself, I'm happy the ban has expired. Not because I want to run out and buy a AK-47, because the ban that expired did not prohibit me from owning an AK-47. Surprised? Yes, Joe and Jane American could still legally own any fully automatic gun they wanted if they were able to jump thru all the BATF's hoops, which involves a tax stamp and proving to the BATF's satisfaction that you are not a convicted criminal and are mentally competent to own a firearm.

So what did this "assault weapon" ban really prohibit? The text of HR.3355, Title XI gives the full details, but in summary it outlawed a combination of cosmetic features on rifles and shotguns and the possesion or sale of detatchable magazines with a capacity of more than 10 rounds manfactured after the date the ban went into effect. Personal ownership of specific firearms were banned because "they looked scary". A terrific basis for a law. Who was safer because these scary firearms were banned? I personally don't know.

I'm glad this ban has expired because it was a bad law that did not do what it was advertised to do.

-ejo

(2004-09-14 10:08:42.0) Permalink Comments [2]

Wednesday September 01, 2004

Windy Point Park

Setting The Scene

The parks grounds are clean and well kept, and overnight camping is available. The camp grounds are fairly unstructured, you seem to pretty much pitch your tent whereever strikes your fancy. There are firepits strewn about, but we found evidence of some brainiac building a fire between the boles of two live oaks. There are also a fair number of sturdy picnic tables on the grounds, as well as "facilities", a changing room and a non-potable water shower.

Off the western shore of the park, there is a very nice scuba park with alot of random sunk objects to find. This weekend we visited the Pinto in 82 feet of water and everything else on the map except the manatee and out-of-service platform.

New Gear

In a burst of unchecked consumerism, I invested in some new scuba gear: an Atomic Aquatics Z1 Regulator and SS1 Safe Second, a Aeris Atmos Elite hose-less air-integrated dive computer, a set of Force Fin Pro Force fins, and a new true color frameless mask ( I can't remember the manufacturer ).

Atomic Aquatics

The real reason I decided on an Atomic Aquatics Z1 first and second stage regulator was because I dove a borrowed M1 and fell in love with it. I bought the Z1 because it was in my budget and because I couldn't find anybody that would say anything bad about Atomic regulators (beyond that they were expensive). The best sources of opinions I found were on Scubaboard.com and ScubaToys.com. ScubaToys wasn't so much a source of opinions, but did have an excellent article which explained what a pneumatically balanced regulator is and why they are desireable.

I chose an Atomic SS1 Safe Second ( a power-inflator/regulator ) due to reviews and it seemed best to have matched regulators so I didn't have to take them to seperate shops to get serviced. The SS1 also allows me to reduce the number of hoses connected to my first stage regulator by one since it combines the my secondary reg with the power inflator for the BC. Maybe not the choice for technical diving or DIR folk, but a reasonable choice for a recreational diver like me.

Both the Z1 and the SS1 breathe like a dream. I've taken them to 87 feet so far, and they breathed the same at depth as they did at 10 feet. I was able to stop the Z1 once while swimming down hard, but I haven't been able to replicate that. Beyond that one glitch, the Z1 has delivered dry air in pretty much any orientation I could come up with ( summersaults, face up, head-down inverted, on my side). The SS1 breathes as well as the Z1 ( and would probably breath better than the Z1 if it wasn't detuned to prevent occasional free-flows on entry or current ). The buttons for the inflator and dump are large and easy to differentiate even when wearing gloves. Mine has yellow buttons and purge cover, and they come in red and blue as well.

The only thing that I'm vaguely dissappointed in is that neither the Z1 or the SS1 comes with the Atomic "Comfort" mouthpiece. You can purchase one for $12 seperately, but it just hadn't occurred to me that they would come without Atomic's signature mouthpiece. Speaking of accessories, I also added the Atomic comfort swivel and M1 exhaust tee to my Z1. The swivel reduces the tug from the hose and increases your mobility, while the exhaust tee directs your exhaled breath out and away from your mask and mostly out of your line of sight. I'm happy with these additions, although sometimes my exhaust would bubble past my ears.

Aeris Atmos Elite

My Atmos Elite came from the shop already linked up with it's transmitter, so I didn't have mess with that ( each transmitter has an individual code so that any number of Atmos Elites can operate in close proximity to each other without interfering ). All that remained was to read the manual and get it wet.

I'm pretty happy with the computer over all. The display is big and easy to read ( when your mask isn't fogged up ), and the buttons are big and accessible. I'm alittle disappointed with the backlight. It was dimmer than I hoped it would be. It would be readable in complete dark, but in the murky dark of 60 to 80 feet in Lake Travis it was not bright enough to read without external illumination. Other than that, it keeps track of a multitude of diving data and presents it well to the diver: depth, temperature, tank pressure, elapsed dive time, estimated air time remaining, automatic safety stop timer, ascent and descent speed, nitrogen loading graph, O2 loading graph, and date and time. The computer allows you to set several alarms: maximum depth, turn around tank pressure, and minimum tank pressure. When an alarm triggers, the computer gives an audio cue (it beeps) and flashes a red LED in time with the beep. The computer will also issue alarms for lots of other conditions which require the divers immediate attention, the most serious of which is entry into decompression mode where the diver will need to make a series of decompressions stops on their ascent in order to avoid decompression sickness (the "bends").

Post dive, it will display your current surface interval, your estimated nitrogen load, minimum elapsed time before you should fly, and access to logs for your previous dives. It will also give you a dive planner which can help you plan your next dive by inputing a depth. The computer gives you a bottom time that is calculated from your current surface interval and nitrogen load from previous dives. Some people claim that the algorithms used by this computer are "aggresive", which I take to mean differs from the US Navy dive tables for recreational divers. I suspect if you dive this computer to the hairy edge of it's estimates you could get yourself in trouble, but the same is true of the dive tables.

The computer stores 24 dives before it starts overwriting older logs, and you can buy a cable to connect your dive computer to a personal computer with USB ports. I'm still waiting on the cable, so I can't really comment on what data is available.

So far, I really like my Atmos Elite.

Pro Force Fins

There is nothing like the subject of fins to raise the hackles of veteran divers. And people seem to either love or hate Force Fin brand fins. Roy had a pair that he let me try, and I decided to give them a chance. My previous fins were Tusa straights which I liked well enough, but I liked the compactness of the Force Fins. I tried the Force Fins first in a local pool and found that without my gear on I didn't really like how they kicked on the surface. Below water though, they felt great! With my straight fins, you really could feel resistance of the water on your fins as you kicked. The Force Fins had far less drag so you feel almost like your kicking with a bare foot. Apparantly it's that feeling that drives some divers to distraction, but this weekend in the lake I adjusted to them within a couple of dives. After this weekend, I put my initials on them and put my straight fins in the closet.

New Mask

I'll write more about the mask when I can identify it by brand and model. I liked it after it stopped fogging up on me, and seemed much more comfortable than my previous Tusa mask.

UPDATE: My new mask is a SeaDive. FYI.

-ejo

(2004-09-01 14:07:13.0) Permalink

Tuesday August 24, 2004

Mansfield Dam Scuba Park

This previous Saturday I dove at the Mansfield Dam scuba park with Roy and his wife. I haven't found any linkage for the scuba park's map, I'll try to scan in the map we were given at the gate. The scuba park facilities are pretty nice ( from my vast experience ). There was a small parking lot and covered shelter that services the park, and a long paved side walk and stairs that leads directly into the water. There is also an elevator for handicapped access which requires a key or something ( I'm assuming you can get it from the park staff ). Last weekend the park was pretty crowded, what with a large group ( 30 odd people ) from Houston doing their PADI Open Water Diver class as well as car loads of random other people. For the most part dive folk were friendly, especially the Houston dive instructors. I had rented a regulator for the day, but the shop missed that the inflator on my Zeagle Concept BCD has a different fitting. Roy picked up the gear, so I didn't spot the problem till we were at the lake and hooking up our gear. I was faced with prospect of diving and controlling my bouancy with the oral inflator, or not diving at all. I approached the Houston folks, hoping they might have an adapter that I could borrow. They didn't have an adapter, but they did have a spare first and second stage that they were willing to let me borrow! I was impressed with their generosity, and if you are reading this Travis, Thanks!

We got our gear on at the car, up in the parking lot, and trekked down to the water ( less than 75 yards I would guess ). I recommend just putting on all your gear but your fins up at the car, it's much easier to carry the tank on your back. The stairs down into the water have a nice sturdy railing, and the stairs end in about five or six feet of water. The dive park itself is reasonablely large, maybe 150 yards deep by 300 yards across, but I'm pretty bad at guestimating distances over water. There were four sunk boats, several platforms, and a small Cessna airplane (sans wings ) sunk at about 60 feet ( lake level at the head was 679.6 MSL ). There were various lines strung along the bottom, so it was reasonably easy to find things once you found the lines. The dive area is well marked with a number of large orange bouys as well as dive flags. And as crowded as the park seemed up top, we only bumped into two groups during the course of our two dives ( one along a line at 40 feet and a class perched on a platform around 30 feet ). Surface water temperature was a nice 81 degrees up top and we enountered a prounced thermocline around 60 feet which dipped to 74 degrees.

All in all, I enjoyed my first visit to the Mansfield Dam scuba park and I'm looking forward to diving there in the future.

-ejo

(2004-08-24 11:34:48.0) Permalink

X10: 1 Erik: 0

So in a previous entry I mentioned my triumph over an X10 appliance module by cutting a trace on the circuit board to disable local control, thereby allowing the module to control a florescent light for a fish tank. I did my testing in the daylight, and thought everything was A-OK. Wrong. One late night last week while stumbling around the darkened house, I noticed a strange flash coming from the fish tank area. It was periodic, every couple of seconds. Further investigation revealed it was indeed the tank light and I'd just subjected the fish to a week of light torture. I mostly don't feel that bad for fish, but that periodic flashing all night for days on end couldn't be good for the light or the fish. So I gave up. I found a Christmas light timer to replace the appliance module, and now it just turns on and off on a mechanical switch. Phooey.

-ejo

(2004-08-24 08:19:52.0) Permalink

Tuesday August 17, 2004

Hey, You Got My Gear Wet!

This weekend I spent some quality time underwater SCUBA diving in Lake Travis, which is a man-made lake just west of Austin, Texas. I enjoyed four dives over two days, with a maximum depth of 58 ft and alittle over two hours of downtime. The dives were supervised by Thomas from Deep Blue Scuba. Both days, we loaded up at Emerald Point Marina on a pontoon-type dive boot and motored over to West Point on the north side of the lake. I had a lot of fun remembering how to dive again. My first dive I managed to lose a dive light tucked into my BC, but managed to find it again on my second dive. The first two dives were just getting comfortable with my gear again and hanging out in the murky waters of Lake Travis. The third dive, my first dive on Sunday, was more interesting.

Another diver (Vincent?) on the trip out told Roy and I about a wall that is near by the dive site. According to this guy, the wall bottoms out at 120 feet and they had dove it the night before. So Roy and I plan our dive; a swim out of the dive area which is just north of West Point, go around the point and descend to about 50 feet, swim out along the wall for about 10 minutes and return the way we came. Our main concern is to get around the point staying as deep as we can since boats are constantly cutting around the point. As you can imagine, surfacing in the path of an uncoming boat would be bad and to be avoided at all costs.

After some Abbot and Costello navigation, we made it to the point and I promptly got seperated from Roy. I was having a series of problems that contributed: my bouancy was positive and I wanted to be negative or neutral, I had a squeeze in my mask, and I had just gotten tangled in a quarter-inch line running from shore down into the lake (probably a trot line). So I cleared the squeeze, dumped my BC, and backed off of the line to get free. Roy hadn't seen me get caught and we got seperated. So I surfaced, got positive (bouancy) and lounged on surface watching Roy's bubble stream meander around me. He surfaced after a bit and we continued our dive together.

Coming out of the cove into the main lake was scary cool. We were swimming in about 25 feet of water, hugging the bottom since we could hear various props above us cutting around the point, when I look up from the bottom of the lake and see inky black ahead of me. The wall dropped off into the dark, and I could see maybe 10 feet down from the edge. I pushed off and dumped my BC and floated down the wall. I was thinking of the movie "The Abyss" at the time, and I was feeling muy macho! It was very cool. We dropped to about 50 feet and followed our plan for the rest of the dive. ( Ok, I made us turn back 7 minutes out due to having consumed too much air during the swim out, but it was close to the plan ).

On the map above, we dove just west of Starnes Island. I did my inital checkout dives at Bob Wentz Park, and next weekend Roy and I are thinking of trying to locate a Cessna airplane sunk somewhere in the vicinity of Mansfield Dam (the southern most flag).

-ejo

(2004-08-17 15:32:34.0) Permalink

Friday August 13, 2004

Perl+DTrace=Instruction Tracing

As promised, an ugly perl script that can be used to generate a custom DTrace script which will generate an instruction trace.

For instance:

trogdor:utrace -> ls
hello*      hello.c     utrace.pl*  utrace.txt* 
trogdor:utrace -> utrace.pl -i hello
trogdor:utrace -> sudo dtrace -Cs hello.t -c hello
...

For the interested, here is the text of the traced program, the DTrace script, and the output generated.

The perl script is no where near "feature complete", nor is it an example of good perl programming practice ( parts of it are legible ). But, say it with me, it scratched an itch :).

-ejo

(2004-08-13 12:54:05.0) Permalink

Second Wind

Dear Diary, been busy.

The Good

This weekend I'm diving in Lake Travis to finish up my PADI open water diver refresher course. I am not an experienced diver ( 7 dives with about 2 hours of bottom time ), but I looking forward to the check out dives and starting again. My friend and cow-orker Roy and his wife have just recently completed the PADI open water diver course and are taking the advanced open water course this weekend.

I'm almost all kitted out, just missing a regulator/first stage and a dive computer. I think I've made up my mind on both, but I'm easily swayed. For regulators, I've been considering the Aeris Sport Pro, the Atomic Z1, and the Mares Abyss. All are solid regs, but lacking an opportunity to try them all I have to fall back on recommendations and reviews. So far I'm leaning towards the Aeris Sport Pro.

The dive computer I've decided on is an Aeris Atmos Elite, which is a hose-less wrist mounted computer with a tank-mounted transmitter ( not a radio apparantly, but something that can wirelessly transmit tank data to the computer ). I considered other air-integrated comptuers as well as other wrist computers. The Aeris appears to give the biggest bang for the buck. The dive instructor I'll be with this weekend uses an Elite, so I'll get a chance to play with it (maybe). The wrist mount seems to be the most conservative place you could put your expensive computer, as well as putting it in a position where it can be checked more often. ( You can always find your wrist, sometimes it's hard to find your console if it's not clipped in. ). It's a lot of cash for an initial purchase, but I'm hoping to avoid having to re-buy gear in the future by going alittle overboard to begin with.

I transitioned from Redhat 7.1 (ancient) to Fedora Core 2 on my machine at home, so I had to spend alot of time migrating services that had I had setup long ago and forgot about. DNS and mail via postfix were the first things to be setup, followed by postfix and spamassassin. I only just now got around to setting up the cron jobs which control all the X-10 lighting around the house, and it feels good to not have to turn lights on and off now. I use a X10 Firecracker serial port dongle to send X10 commands wirelessly to a wall-plug mounted receiver. The Firecracker is pretty neat, but uni-directional so you can't query device status. I just ordered a bi-directional dongle from X10.com, but haven't had a chance to play with it yet.

My wife recently got our new fish tank set up, so I thought it would be convenient to plug the tank light into an X10 appliance module. After all, that worked pretty well with the last tank. Wrong. It turns out that run-of-the-mill X10 appliance modules have a feature called "local control" which monitors the draw of the plugged in device somehow (I'm not an electrical engineer and don't pretend to be ) to see if you are trying to turn it on when the module is off. When it sees a draw or whatever, it obliges you and turns power on. This is all well and good for regular appliances, but florescent lights are a whole different animal. You can turn them on and then turn them off, but after a 2 second pause they turn right back on again. It's like having a very annoying ghost. Well, on www.smarthome.com they have a convenient FAQ which addresses just this question. On the particular module I have, you can disable the local control circuitry by opening the module and cutting a trace on the backside of a small circuit board. I gave it a try, and what do you know, it worked. Of course I managed to damage my thumb while doing this, but I like to think that spilling my own blood somehow enhanced the probability that it would work on the first try.

The Bad

Luckily, this section is sparse. My dog Sam is still limping since getting accidently trampled over the 4th of July, but seems to be getting slowly better. She has always had trouble with her right rear leg, but she's not getting any younger and doesn't bounce back quite as fast. She is mostly a three-legged dog now, but every day she seems to be putting alittle more weight on it.

I cut the dickens out of my thumb cutting the aforementioned X10 circuit board trace. I knew I was tired, but I wanted to see if it would work. As I was digging into the board with my pocket knife, I remember thinking to myself "If the blade slips, I'm gonna cut the snot out of my thumb." And then the blade slipped. So the moral of this story is: If you are tired and it involves knives, wait until you aren't tired. And if you think you are going to cut yourself, you probably will. My previous serious injury with a chef knife started with me being tired and thinking that I was about to cut myself. Well, it seemed serious to me; the finger nail eventually grew back.

The Ugly

I can't put the instruction tracing thing away quite yet. DTrace is slower at instruction tracing than my user trap handler tracing tool, but the amount of effort that I had to invest using DTrace was significantly less. Since the DTrace pid provider allows you to specify probes by offsets into functions (rather than by pattern matching instructions or mnemonics), I thought it might be fun to write a perl script which takes a victim object and generates a DTrace script with probes for just the control transfer instructions (CTIs). It's not quite done yet, since I haven't written any perl in quite some time and have forgotten alot more than I expected :). Firing a DTrace probe every 5th instruction on average should go a long way towards reducing the DTrace impact on the program under test. Whether it's interesting to anybody is a whole 'nother question!

-ejo

(2004-08-13 10:58:40.0) Permalink Comments [1]

Thursday July 29, 2004

DTrace Instruction Tracing Continues..

Wow, this has me bugged. Using this script ( called itrc.d ):

pid$target:a.out::
{
        printf("%d %016llx",vtimestamp,uregs[R_PC]);
}

# dtrace -s itrc.d -c hello3 > rtrc.hello3

a custom SPARC disassembler, and a really awful perl script, I produced:

Delta NS Address          Instruction   (disassembled)
       0 0000000100000740 bc102000      or      %g0, 0x0, %fp
   12960 0000000100000744 e05ba87f      ldx     [%sp+0x87f], %l0
    7120 0000000100000748 1b000000      sethi   0x0, %o5
    5040 000000010000074c 9a136001      or      %o5, 0x1, %o5
    4960 0000000100000750 9b2b7020      sllx    %o5, 0x1020, %o5
    4640 0000000100000754 13000403      sethi   0x100c00, %o1
    3920 0000000100000758 9212400d      or      %o1, %o5, %o1
    4240 000000010000075c e0226208      stw     %l0, [%o1+ 0x208]
    4240 0000000100000760 a203a887      add     %sp, 0x887, %l1
 ...

I think I'm almost done.

-ejo

(2004-07-29 14:28:54.0) Permalink

DTrace Instruction Tracing

Adam Leventhal pointed out that the DTrace pid provider can instrument user-land instructions, so my interest was piqued enough to give it a whirl last night. The script I ended up with is just stupidly short, I feel like I'm cheating.

pid$target:a.out::
{
        printf("pc %p: %x",uregs[R_PC],*(uint )copyin(uregs[R_PC],4));
}

Using a new DTrace feature, I start the trace and get some output:

# dtrace -c ./hello2 -s itrc.d 
CPU     ID                    FUNCTION:NAME
  0  38695                     _start:entry pc 1000006a0: 91d02038
  0  38696                         _start:0 pc 1000006a0: 91d02038
  0  38697                         _start:4 pc 1000006a4: 91d02038
  0  38698                         _start:8 pc 1000006a8: 91d02038
...

That doesn't look right. The PC's look good, but those aren't the instructions at those addresses. Or are they? I was a bit foggy last night when I started messing with this, so I assumed that I wasn't using copyin() right. Somehow I was getting the address of the DTrace buffer that copyin returns or something. In the cold light of morning things look different. It occurs to me that 91d02038 looks familiar. Yes I know, it's numbers. The crawling itch in my lizard hacker brain was trying to tell me something:

91d02038 <=> ta      %icc, 0x38

What? Your lizard hacker brain doesn't tell you stuff like that? Lucky you. So I was using copyin correctly. I am fetching the instruction at the PC, just not the original instruction. As everybody knows, 0x38 is the DTRACE pid provider trap, so this instruction is the DTrace instrumentation that makes it all work.

I'm feeling moderately clever for having figured that out on only two cups of coffee. :)

-ejo

(2004-07-29 08:17:52.0) Permalink Comments [1]