Archive for the Computers Category

Oceanic Cable Internet Outage 28may17

Posted in Computers, Networks with tags , , on May 29, 2017 by marksun

Oceanic Cable lost internet service, among other things on Sunday night … came up at 0900 Monday, down at 0930, back up finally 1120.   It could well have been a problem caused as a side effect of work on restoring  local TV feeds, apparently still down 24 hours later, but no idea really what the issue was.

Notes on this event.  I guess the main think is that when the internet comes back, all devices start working by themselves.  User need not do anything but wait, so no action at all is required.

Indications on my SURFboard SB6144 DOCSIS 3.0 cable modem were only two blue LEDS lit.  Normally we get two solid blues ( receive and send) and a flashing blue ( router connection)

Failure mode:

  • Blue receive data,
  • Blue Gig E mode light ( indicator that the router is connected).

 

 

 

Canon MP640R Printer B200 Error

Posted in Computers with tags on March 22, 2017 by marksun

Looks like the end of the line for the Canon MP640R printer.  Out of the blue, we get this B200 error  with the onscreen message to “remove the power connector and call the service center.”

b200.JPG

Following some googled info, I could recovery to apparent “normality” by  power off,  lift cover and platen up to expose the printhead, power on, closing cover quickly before printhead moved to the left rail.  Couple of times, the printer booted to its normal menu without error.  In this state I was able to print – once. The output is showing alignment errors and there was an immediate return to the B200 Error.  If I could get it to print consistently I’d at least use it until the ink ran out, but it’s not going to make it.

There are some posts from people who say they have recovered from this error.   Hard to know because it’s the Internet – but one amusing if disturbed YouTubed fix is really a video of the “final solution” approach.   There are videos that show that cleaning this part can fix the B200 error.  I’m curious,  but not enough to go down that road.  This is not a glitch, it’s a hardware failure. This printer is seven year old.

The culprit: probably the printhead.  A serious repair approach would be to replace the printhead, which is the carrier which holds the print cartridges, and easily lifts out of the carriage. This is a $30 to $50 ebay/Amazon part.  I’m tempted but this time, I’ll scrap the printer. Seven years is enough.

To make things complete, it appears that the Canon 220 and 221 printer cartridges are obsolete.  I’ve maintained a one-deep inventory of these things so I’m out about $60 or $80  in now useless cartridge inventory – about half the cost of a new printer!  Anybody want to make a deal?  Venmo me $50 and I’ll priority mail them to you – all the partly used cartridges – including a new CYAN,  new backups including two yellows, 3 small black, and a big black. ( Mar 22 2017).

Overall this printer when it worked has been the least aggravating of the home printers I’ve owned.  I’ll probably stick to a Canon Pixma inkjet.  We’ll see if the BuyMore down the street has something in stock at a reasonably competitive price to Amazon…

  • small footprint
  • 5 cartridge
  • wifi
  • scanner
  • print duplexer
  • rear photo paper tray
  • don’t care
    • ethernet
    • SD print
    • USB / Blutooth

DVD player in Windows 10

Posted in Computers, software, technology with tags , on June 12, 2016 by marksun

Recently learned that Windows 10 does not ship with a DVD player and that an upgrade to Windows 10 kills DVD playback.

 

Microsoft stopped DVD support in Windows 8 and continues in Windows 10. The reason are patent protections for key software components:

  1. MPEG-2 decoder.  A manufacturer must pay $2 per copy of this software.
  2. Dobly digitial audio:

You can get around this by using VLC as a player.  This may also be the case with apple whose video players do not carry a license for Microsofts old .msi format.  VLC is a free open source cross platform that circumvents patents by an interestering assertion:

Patents and codec licenses Neither French law nor European conventions recognize software as patentable (see French section below).

Therefore, software patents licenses do not apply on VideoLAN software.

VLC contains the following:
libdvdcss – find and guess keys from DVD to decrypt it
libaacs – advanced access content system

References

Ed Bots article: http://www.zdnet.com/article/if-vlc-can-ship-a-free-dvd-player-why-cant-microsoft/

Wiki: https://en.wikipedia.org/wiki/Advanced_Access_Content_System

This link is somewhat self explanatory.  It describes hacks to copy library and a keys database files to VLC’s production directory to enable Blu-Ray playback.

https://www.quora.com/How-do-you-get-your-VLC-2-0-to-play-encrypted-Blu-Ray-discs

 

Tweakbit Malware

Posted in Computers with tags on May 17, 2016 by marksun

Addware called Tweakbit showed up on an Asus laptop.  Tweakbit is nominally a system cleanup utility but in reality it is Addware.  It just showed up on bootup front and center on the screen. If you see it, you need to get rid of it.

Uninstall cannot remove it.

The Fix.  HitManPro-  For current and future reference, this is legitimate and effective software.

  1. download “hitmanPro”
  2. run a “one time only” malware scan
  3. to clean the system, proceed – you will need the temporary license
  4. let HitmanPro run
  5. reboot
  6. go to Control Panel > Programs and Features
    • uninstall Tweakbit

Step 6 turned out to be necessary to get rid of the last trace of Tweakbit.  HitmanPro did not affect the link in the Uninstall utility.  Uninstall reports that Tweakbit has already been uninstalled.  That’s OK and go ahead an remove Tweakbit.

HitmanPro does not appear in the list of installed software.  It may be that the one-time scan is just that and HitmanPro leaves no obvious trace of itself afterward.  Interesting to see software with good manners for a change.

If there are any after-shocks I’ll update.

windows 8.1 cannot connect to this network

Posted in Computers, house tech with tags on May 16, 2016 by marksun

One day this  Asus SonicMaster Core i3 Win 8.1 laptop got turned on and the wifi was down with the error “Cannot connect to this network.”   No amount of troubleshooting on the laptop fixed it.

The last thing I did – logged into the router admin menu with a browser and checked the router security config.

Post-script – I didn’t reset the router by unplugging at this point.   In retrospect, you should try this first!

Cause – the router security configurations changed from WPA2 Personal, to WPA2/WPA Mixed Mode Personal.  Why? I don’t recall.  No doubt however that it was me that changed it – probably several days ago because I am working on this network a lot – certainly by mistake since we’re using WPA2 Personal .  Did not catch it because no other device was affected including the Amazon Fire box (which would have brought the house down).

Fix – change router security to WPA2 Personal

Outcome: Windows 8.1 box regained network connectivity.

 

SMTC – for the Hawaiian Islands

Posted in Computers, weather with tags , , , , on February 23, 2016 by marksun

Sun Moon and Tide Calendar for the Hawaiian Islands

Way back when, I wrote this sun moon and tide calendar program in C. There were a number of critical information sources to make this possible.  In a way the foundation for me was based on a little booklet of  astronomical calculations (Astronomical Formulae for Calculators, Jean Meus 1979) which provided detailed methods to calculate all kinds of astronomical numbers like rise and set times, azimuths, altitudes, you name it.  The scientific calculator had arrived and now the average guy could do some serious calculation relatively quickly.  Tide calculation is a bit rougher, but I found somewhere in Hamilton Library at the UH  from the Government called Numerical Tide Prediction which opened the door to doing it yourself.  There was a Fortran program and I got a copy.

SMTC  required building a C library from Meus’ equations, and translating the government fortran to C, and a few other odds and ends involving the Hawaiian lunar calendar, a primitive map system, and innumerable computing problems that had to be solved to make this work on pre-Windows PC.   For all that, it’s remarkable how well the system held up. The last  release of SMTC was in March 1995.   Some of the code goes back to 1989 and earlier, so this project started  in the 80’s – when my kids were born. Now SMTC lives again on a VM on this Windows 8.1 machine which won’t even run an EXE file that old.  It’s satisfying to see this primitive program is still producing accurate and useable results – good enough for “Hawaiian” time.  I have the source code still and I would seriously like to port it to a modern language that would allow it to run on Windows, Linux and web platforms.

smtc

Figure 1. SMTC main tide display.  Harbor, lat/long, Date, Sunrise, Sunset, Moonrise and Moonset calculated for the harbor in HST, Lunar night in the old Hawaiian system, graphical tide chart computed for each hour using Honolulu Harbors harmonic tidal constants.

In the 70’s  and 80’s I became interested in the traditional and the nearly lost Hawaiian Lunar (Mahina) Calendar. At that time there were already a couple published calendars, one a large wall calendar by the Hawaiian Civic Club – really the groundbreaking compilation of information from the very few authoritative sources – David Malo’s Hawaiian Antiquities, and writing by Kepilino (Kepelino’s Traditions of Hawaii).  The Hawaiians and other Polynesians certainly were in possession of an extensive body of knowledge of the moon’s phases, and how the mahina, or nights of the moon, related to tides, fishing, agriculture, and the many rhythmic cycles of day to day life.  I had a go at publishing Hawaiian Sun Moon and Tide Calendars for a few years myself but as a business venture it was a disaster!  SMTC the computer program came as a next step and for me fused Hawaiian traditional knowledge with the mathematics based knowledge of the Western world – calendar math, well known and painstakingly derived astronomical formula relating to the sun, moon, major planets.

Tides  have been the subject of scientific scrutiny  for hundreds of years and the flow of water has long been known to respond to lunar and solar gravitational influences, local ocean currents and heights, wind, etc.   At some point some genius subjected tide observations to  harmonic analysis, the theory being that the tide height at any point was the sum of multiple separate simple harmonic fluctuations that varied in wavelength, height, and phase.  In Hawaii, 38 separate components have been discovered to explain most of the variation in the height of the tides in.  In the late 80’s I found this method in a paper called Numerical Tide Prediction, which also mentioned the existence of a Fortran program.  I was able to get a copy, must have been sent to me by mail on floppy disk, and I got it working using a tiny Borland Fortran compiler.  The program implemented the numerical method in a way that can only be understood in the computer language Fortran. In other words it was terrible.  To make it usable, I rewrote the core of NTP in C and incorporated this code in  in SMTC.  This program written in the late 80’s and early 90’s is still accurate in 2016 with no input or adjustment at all.  The validity of the method has certainly stood the test of time, while at another level illustrates the importance and short term, at least, constancy of rhythms in nature.  Based on math alone, tides can be predicted with an amazing degree of precision, give or take the deviations caused by another fundamental force in nature – the noise of day to day randomness of our environment, weather, wind, storm waves and so on.

In SMTP, the Hawaiian lunar phase name are computed by calculating the age of the moon since the  astronomical new moon.  The first night is Hilo, the first sliver of the moon appearing like a twisted strand of silver fiber in the twilight of  the western sky after sunset.  It’s real easy to waffle around with the full moon, and quarters, but the sky tells the story when it comes to the new moon when the moons orbit brings its face to the point where it is directly opposite the sun, dark,  from the perspective of we earthlings.  In virtually all folk-lore, the new moon is the dark night with no moon, and the next night the moon’s light reappears in the western horizon.  The ancients would have had to deal with the realities of nature and the fact that the lunar month is never in exact synchrony with the solar day.  The astronomical lunar or synodic month varies from about 29.18 to 29.93 days with a long-term average duration of 29.530587981  (see Wikipedia – lunar month). Malo and Kepilino both say the ancients dealt with this by alternating 29 and 30 night months, with the result of some months ending in either Mauli or Muku, adding an intercalenary night every so often, etc. etc.  My guess is that in the old days there was no need to calculate out a new moon or full moon for anything like years in the future.  Errors would creep into a simple integer accounting system for the moon. Those in the know who observed the sky were probably practical observers and called the nights as they saw them. In any case they were fully capable of predicting lunar phases accurately months in advance if needed.

To render the individual moon, I did the spherical math to project the terminator out from the lunar phase angle more or less for the heck of it.  Who cares eh? Next time around I’d use a jpeg icon.  Back then jpeg had not been invented yet.

smtcWk

Figure 3 – tides for a seven day period

Sadly, SMTC program is hard-coded to have a lifetime from 1940 to 2025.   It depends on a binary database file called ntp4025.db which must be in the same directory as smtc.exe.  So after 2025 – the original SMTP will cease to work.  I think that the tide harmonics were thought to have a finite useful life and would not be valid beyond 2025 so I figured, we’ll just go with that.  I may have thought that there would be replacement by then.  Or that nobody would care. Shucks.

smtcMap

Figure 3. Harbor selection screen.  As you page through the harbors, the location is plotted on the map.  These are hand-digitized lat/long baseline maps.  Crazy.

So while SMTC shows its age and has a primitive patina, it is not trivial. To this day nothing comes close to packing the functionality of this little program into a single bundle.  So I think it’s worth revisiting but it will probably take another labor of love to pull off.  The target platform this time is the Raspberry π.

ntp4025.db and notes to self.  I apologize in advance for this paragraph but if I don’t write this down I’ll forget.  It should be edited out in due time.  This 25.6kb binary  data file was generated in 1989 and I don’t see the source that created it but most likely a dump of structs.  ntplib.c calls init_tables with a callto loadannv(yr,lastyr,npdb_file) — there is some kind of annual data lookup.   For some time I preferred binary data files, probably to hide and keep it to myself… ego!  Ah youth!  Well, actually back then with 10MB hard drives and 360K floppy disks, small was beautiful.  But would an ascii data set really have been smaller than 25K?  These days I vastly prefer clear text ascii data.  We take it to extremes of course.  People think that XML is god’s gift to programmers, but markup language is a back to the future thing isn’t it?  Remember “Wordstar”?  Probably not!  Anyway were it not for ntp4025.db SMTC could live forever or at least as long XP lives – somewhere?

Bad idea.  But waaayyy too late now … we’d have to reverse engineer it, but more than likely, we’ll know how to work around it.

– the harmonic constants for Honolulu are online here.

https://tidesandcurrents.noaa.gov/harcon.html?id=1612340

https://tidesandcurrents.noaa.gov/stationhome.html?id=1612340

These NOAA pages are a remarkable instance of full disclosure of valuable and hard-won information and totally define information that should remain in the public domain.  Great service NOAA!  Impressive.

Just in case…  printing out the Honolulu harmonic components which enable the computation of tide charts.  These are likely to be the latest and most accurate set of constants.

Just for fun I ran a check of the SMTC source code to see how much drift there may be in the harmonic constants for Honolulu after 20+ years. In ntplib.c , the  array float amp[38]  corresponds to Amplitude,  array a[38] is Speed, and  epoch[38] is Phase.  The constants have been revised a bit:  e.g. M2 Amplitude is 0.58 in the harmonic chart below, and in my constants from 1995 M2 the value is .0546.  The numbers still track however.  SMTC tide predictions are still close to currently published tides for Honolulu.  I would say that the discrepancy is practically speaking unimportant – nature is way more complex than the computer model – what is remarkable is how well tide and astronomical calculations hold up.

Just wondering about what might change.  SMTC almost certainly uses the 1960-1978 epoch tidal datum.  Maybe the depth of the water has changed, or currents and coastline changed.  Looking over these numbers (and I haven’t checked the program) I wonder how important these zero amplitude constituents are… M4 or M6 for example… there are a number of them.

Tidal Datum Analysis Period- Epoch
01/01/1983 – 12/31/2001  – current epoch
1960-1978 – superceded epoch
Constituent # Name Amplitude Phase Speed Description
1 M2 0.58 129.6 28.984104 Principal lunar semidiurnal constituent
2 S2 0.19 113.8 30.0 Principal solar semidiurnal constituent
3 N2 0.11 125.1 28.43973 Larger lunar elliptic semidiurnal constituent
4 K1 0.52 76.5 15.041069 Lunar diurnal constituent
5 M4 0.0 0.0 57.96821 Shallow water overtides of principal lunar constituent
6 O1 0.28 76.2 13.943035 Lunar diurnal constituent
7 M6 0.0 0.0 86.95232 Shallow water overtides of principal lunar constituent
8 MK3 0.0 0.0 44.025173 Shallow water terdiurnal
9 S4 0.0 0.0 60.0 Shallow water overtides of principal solar constituent
10 MN4 0.0 0.0 57.423832 Shallow water quarter diurnal constituent
11 NU2 0.02 135.6 28.512583 Larger lunar evectional constituent
12 S6 0.0 0.0 90.0 Shallow water overtides of principal solar constituent
13 MU2 0.02 89.1 27.968208 Variational constituent
14 2N2 0.01 118.6 27.895355 Lunar elliptical semidiurnal second-order constituent
15 OO1 0.02 91.4 16.139101 Lunar diurnal
16 LAM2 0.0 122.3 29.455626 Smaller lunar evectional constituent
17 S1 0.0 0.0 15.0 Solar diurnal constituent
18 M1 0.02 95.3 14.496694 Smaller lunar elliptic diurnal constituent
19 J1 0.03 83.6 15.5854435 Smaller lunar elliptic diurnal constituent
20 MM 0.0 0.0 0.5443747 Lunar monthly constituent
21 SSA 0.0 0.0 0.0821373 Solar semiannual constituent
22 SA 0.13 191.0 0.0410686 Solar annual constituent
23 MSF 0.0 0.0 1.0158958 Lunisolar synodic fortnightly constituent
24 MF 0.02 37.2 1.0980331 Lunisolar fortnightly constituent
25 RHO 0.01 76.2 13.471515 Larger lunar evectional diurnal constituent
26 Q1 0.05 74.3 13.398661 Larger lunar elliptic diurnal constituent
27 T2 0.01 114.3 29.958933 Larger solar elliptic constituent
28 R2 0.0 113.1 30.041067 Smaller solar elliptic constituent
29 2Q1 0.01 76.0 12.854286 Larger elliptic diurnal
30 P1 0.16 76.6 14.958931 Solar diurnal constituent
31 2SM2 0.0 0.0 31.015896 Shallow water semidiurnal constituent
32 M3 0.0 0.0 43.47616 Lunar terdiurnal constituent
33 L2 0.02 134.0 29.528479 Smaller lunar elliptic semidiurnal constituent
34 2MK3 0.0 0.0 42.92714 Shallow water terdiurnal constituent
35 K2 0.05 107.0 30.082138 Lunisolar semidiurnal constituent
36 M8 0.0 0.0 115.93642 Shallow water eighth diurnal constituent
37 MS4 0.0 0.0 58.984104 Shallow water quarter diurnal constituent

Protected: HomeGroup Bellpepper and Peter KH6DK

Posted in Computers with tags , on February 18, 2016 by marksun

This content is password protected. To view it please enter your password below: