Archive for the ‘Misc Stuff’ Category

Vintage Humor

Friday, April 18th, 2014

I found this in Volume 1 – Issue IV of the SCELBI Computer Digest, which can be found online at



skinned knuckles

Sunday, April 13th, 2014

Last night, a little after midnight, I finished replacing a power window regulator in my wive’s mini-van. I’ve done motors before, but not the regulator. I expected the job to come with a few obstacles to overcome and I wasn’t disappointed. I’d like to know how they connect the lock rods and lock actuator in manufacturing – what a pain. It also took some time and effort to get the window properly seated in the regulator guides, but I think that might have been an issue with the aftermarket regulator that I bought.

The reason why I do this is cost – my cost was $70. The last time I had one repaired by a shop, it was over $400.

Proposed PS/2 Keyboard Adapter Stretched Strobe Change

Friday, April 11th, 2014

As I mentioned in a previous post, my PS/2 keyboard adapter requires some strobe stretching in order to work with some kinds of early microcomputers, such as some OSI models.

I think I have come up with a convent way to accomplish this, with only a small firmware change.

Here is what I have in mind.

As before, when the CR jumper is inserted, it disables recognition of the CNTRL-RST and CNTRL-CLR keyboard/RS232 sequences, which assert the reset or clear screen outputs, as appropriate. With my new design, in addition to disabling the aformentioned reset and clear sequences, inserting the jumper will change the clear screen output to an input. Now here is the key part of the change; whenever a character is typed and strobe is asserted (high true), if the CR jumper is inserted, strobe will remain asserted until:

  • minimum of 125 useconds have elapsed AND
  • the input to the clear I/O port is asserted (also high true)
  • To maintain current behavior (a 125uSec long pulse), you just need to tie the strobe output directly to the clear input.

    In order to stretch strobe out a bit, you have a few options:

  • Tie strobe output to clear input through an RC timing network in order to slow down the response to the clear input. For example – connect strobe and clear together with a 10K resistor. Then connect the clear input side of the resistor to a 1 uF capacitor and connect ground to the other side of the capacitor. Doing a basic RC timing equation shows that this should yield a delay of approximately 10 milliseconds. Change the values to attain a strobe length that meets your requirements. You do have to be careful to limit current through the resistor, so you don’t blow the strobe transmitter, though.
  • Use external logic of your choice to assert the clear signal to the PS/2 adapter
  • Behavior with the CR jumper disconnected is exactly the same as with the previous version of firmware.

    The main assumption behind this change is that the clear output, is only required for the Apple 1. I have found little to no need to disable CNTRL-RST and CNTRL-CLR on the Apple 1 (or Apple II) and those features are probably of little value to other platforms. In any case, the PS/2 keyboard sequence of CNTRL-ALT-DEL will still assert reset no matter whether the CR jumper is in place or not. In fact, using the CNTRL-ALT-DEL combination from a PS/2 keyboard will be the only way to assert reset if a system needs both reset AND a stretched strobe output. Said another way, you will not be able to assert reset from a device connected with the RS232 port, if your system also needs a stretched strobe.

    I’ll do some trials over the weekend and assuming that it works ok and I get no better input or ideas, I’ll have a new version of the firmware available very soon, possibly as soon as next week.

    Old Barndoor Telescope Sky Tracker

    Wednesday, March 5th, 2014

    Barndoor Tracker Movie (click on this link to see movie)

    I recently pulled this old 2006 project out of mothballs and it still works. You mount a small camera or telescope on it. You point the axis at the celestial north. Turn it on and it follows the rotation of the earth, so you can take long exposure pictures of the night sky. I only took one roll of film using it and before I was able to take a good look at the results, the negatives disappeared, so I don’t really know how good it worked.

    It features speed, direction controls and a clock for timing the exposure.

    Visiting Arlington National Cemetery, August, 1964

    Friday, November 22nd, 2013
    Arlington National Cemetery Aug, 1964

    Arlington National Cemetery Aug, 1964

    Arlington Nation Cemetery, second picture

    Arlington Nation Cemetery, second picture

    People in History with Narcissistic Behavior that Acheived Great Things

    Friday, October 25th, 2013

    I finally read Isaacson’s book on Steve Jobs and got to thinking about his narcissistic behavior. Though living around this sort of person is extremely difficult, he achieved great things. The question I have, was his narcissistic behavior part of what made him so successful or was this behavior something he had to overcome to achieve success?

    Here are some other examples of narcissistic people that achieved great things.

    Greek King Alexander the Great
    Roman Emperor Caesar Augustus
    French Emperor Napoleon Bonaparte
    United States General Stonewall Jackson
    United States Entrepreneur Henry Ford
    United States General George Patton
    United States Entrepreneur Steve Jobs

    I’m omitting people that had narcissistic behavior that caused great harm to society, that will be another list.

    Can you think of others? – interesting facts

    Sunday, September 29th, 2013 was created in March of 1999.

    During the entire first year, the server counted about 5000 “page views”. I can plainly remember how happy I was when the count reached 10,000 after over 2 years of existence.

    During the first 9 months of 2013, the server counted between 53000 and 150000 “pages” downloaded per month for a total of 802,000 “pages” downloaded. Over the last 12 months almost a million “page” downloads have occurred.

    Believe it or not, my page on breeding Jack Dempsey tropical fish is my most popular page. I believe the reason for this, is that this fish is readily available in most retailers here in the US, even though it is a terrible choice for most fish keepers.

    It seems like the hit count on my retro computer pages, specifically the Apple 1 registry, are closing in and could knock the Jack Dempsey off the top spot in the next year or two.

    Can you figure out what this person is requesting?

    Thursday, September 19th, 2013

    Occasionally I get emails with cryptic requests, most often from folks from non-English speaking countries. Some are SPAM, some not. This is one of the most cryptic that I have ever seen. Do you think I should reply and ask for more information?

    Subject: Prom provramming
    Date: September 19, 2013 9:01:34 AM EDT

    First of all i admire people like you that release that what they know to the people in the word
    I search the prom code that can programming into the ptom that started the screen monitior opporation.
    If you tell me when if it possible to get this i will thank you

    Have is nice day
    name removed
    If it is cost mony tell me

    How Much Should 20 SCELBI Faceplates Weigh?

    Friday, August 16th, 2013

    THis question came to mind when determining why shipping cost from all the way across the country was only $4.95, which seemed low.

    I calculated this three different ways using the measurements of .1″ x 11″ X 12.75″ for the aluminum faceplate.

    1) Use this online calculator result was 1.4 pounds per piece for a total of 28 pounds. Actual weight should be a little less, because of the holes in the pieces.

    2) I looked up the mass of aluminum which is 2700 KG/M3. Then calculated the volume of 20 faceplates at 0.000226209 cubic meters. Multiplying the two results in 1.34 pounds per plate times 20 plates equals 27.87 pounds. Actual weight should be a little less, because of the holes in the pieces.

    3) Then I realized I should have just looked it up in the tracking information. Sure enough the weight of the package is 26.1 pounds, which is about what the calculations minus the holes showed it should be.

    I still don’t know exactly how the shipping was so low, but I’ll take it, knowing I have over 25 pounds of faceplates on the way.

    On Arron Hernandez and the Patriots…

    Wednesday, July 10th, 2013

    This is one of my rare (I think) rants.

    In case you didn’t know, New England Patriot football star Arron Hernandez was recently arrested for murdering an acquaintance.

    On sports radio and in other media outlets around the Boston area, there is steady stream of analysis about what happened and could it have been prevented, or at least did the Patriots knowingly, or should they have known that they hired a thug in order to better their football team.

    In my mind, this is an open and shut case – anyone in a major business doing any hiring, besides doing interviews, will be required to do background checks, before the hiring takes place. This should include reference checks with credible individuals familiar with the candidate. I’m sure that in the top ranks of pro and college football, the Patriots, with a little do-diligence could have determined that Arron was not a good person. This should have been enough to steer them away from this thug. In fact, other teams did determine this, and passed on him. That the Patriots have a track record of bringing in problem players such as Corey Dillon, Randy Moss, Albert Haynesworth, should only go to show that their hiring practices are very suspect.

    Winning is important in the NFL, so important that hiring decisions are routinely made that would never happen in a “normal” business. Think about it, if you were a Patriot employee, would you want to be around such characters as Corey Dillon, Randy Moss, Albert Haynesworth and Arron Hernandez on a daily basis. The Patriots are not the only ones at fault here, many, if not most teams have hired thugs over the years. One example, being recent Superbowl MVP, Ray Lewis. I personally think the NFL should smarten up and try to hire only people with outstanding character. Sure, they might miss out on some talent, and make some mistakes along the way, but if everyone is doing their best to weed out the bad apples, then it shouldn’t be a big issue. Anyway, if you were running a unbelievably successful business, would you hire a thug, if he potentially might earn you a few more dollars. Or would you do the right thing for the community and your employees, who have to work with this person on a daily basis and stay away?

    I’m all for giving people the chances that they merit, but there is no excuse for a top notch organization knowingly and repeatedly hiring bad apples and then acting surprised when something goes wrong.