Category Archives: Tech

Dad’s Custom Stereo

Posted on by

My Dad, Dave Johnson was an audiophile in a time before the word came into widespread use. An avid fan of modern Jazz in his youth, he came of age in the 1950s. While 33 1/3 RPM records were well established as the contemporary standard, stereo had not yet come to market. I’m not sure what year it was when he built his audiophile stereo system but it was around the time that stereo records were just starting to become available starting in 1958. It was made up of a pair of Heathkit Preamplifiers, a pair of 20/25 Watt Heathkit Power Amplifiers, a Music Master Idler Drive Turntable and a pair of 2 way speaker cabinets he built from scratch. Here are some pictures of the amps and turntable…

The Power Amplifier…
Heathkit W5M

The Preamplifier…
Heathkit WAP Preamplifier

The Turntable…
Music Master Idler Drive Turntable

No photos of the long gone speaker cabs though.

I have many fond memories of listening to that system as a child

Theory of Operation and Calibration: D.C. Johnson FAC-1

Posted on by

Here is another D.C. Johnson and Associates Inc. product from 1984, the FAC-1. This is the most prolific device of it’s kind. Originally designed in 1981 by Dave Johnson to retrofit European market version cars built from 1977 to 1986 equipped with a CIS Electro-Mechanical Fuel Injection System known as K-Jetronic. Tens of thousands were manufactured and installed. Many are still in service today.

The D.C. Johnson FAC-1 is an Air/Fuel control unit. It adds the closed loop Oxygen sensor feedback loop to CIS Fuel Injection Systems not originally equipped with this feature. It was designed to retrofit cars built for sale in the European market before emissions regulations were instituted. This add on allowed them to meet United States specifications after they were imported into the United States of America.

ENGINEER”S NOTE: One of my “Hobbies” is upkeep of the legacy of this product line created by my Father, David C. Johnson. These devices were produced from 1981 through 1986. The company that manufactured and marketed them (D.C. Johnson and Associates Inc.) was founded in late 1982 and was closed in August 1986. I created the website dc-johnson.com in 2008 after an inquiry into the availability of technical information. This led to the realization that there was an ongoing interest in maintaining theses products and the cars on which they are installed.

Vernon Johnson August 5, 2014.

More about dc-johnson.com.

If you have found this video useful, please consider supporting dc-johnson.com with a donation.

PC Speedy Phone Scam

Posted on by

Monday Monday! Got a call this morning from “PC Speedy” 🙂

Not a lot of time to play today so here is an example of a “Go away quickly” script. They get discouraged fairly fast when there doesn’t appear to be a good mark on the line…

If you get one of these calls and have some time, keep them on the line as long as you can. You will be doing your part to help prevent other more vulnerable people from being robbed. Seriously. hanging up has no effect and sometimes they just call right back. Identify yourself as an unprofitable target and they won’t call back. If you can, record the call, toy with them (that typically angers them once they catch on). If you have the time, waste their time. It takes time away from them for other calls and can help prevent others from being robbed.

PS: IF you record one of these calls please share it with Engineer LLC to help keep people informed.

The state of Malware: Mid 2014

Posted on by

My family participates in a Community Supported Agriculture (CSA) program where we pay a Quarterly Membership Fee and receive a basket of fresh locally grown vegetables and fruit every two weeks. Apparently, their mailing list was also recently “harvested” for what appears to be less legitimate purposes.

I received the message below this morning (6/27/2014). The timing was such that my initial reaction was “Good, it’s an announcement on the July 4th holiday CSA schedule adjustment”. But then I saw the link text and the fact that the link was pretty much all that was in the message body. Alarm bells went off… So, out of curiosity, I did an analysis of where this thing is coming from. See that below the original message, if interested.

From: My CSA [mailto:redactedRealAttorney@Redacted-Real-Law-Firm.com]
Sent: Friday, June 27, 2014 5:17 AM
To: RecipientYouShouldntHaveSpammed; numerous other recipients…
Subject: from CSA
Hi!

News: http://blog.carpediem.in/xxx/@@@@@@@.php

My CSA

So what was the payload? The link above was pasted (unredacted) into a private browser on a secure remote server and it produced an application window that looked like an Internet Explorer browser full of phony “Diet News” and suspicious related as content. An attempt to close the window with the upper right red X brought up a new window with an “Are you sure… blah blah blah and an OK button that would likely install the mailware. Some other time maybe.

Analysis:

The first clue it’s a malicious message is the link URL. The domain carpediem.in just doesn’t equate with my CSA and the TLD (top level domain) of .in means it is a registration originating in India. Furthermore the file type (the .php) of the page in the link indicates it is a dynamic page and possibly some sort of application that seeks to do something malicious.

Analyzing the header of the message reveals more clues…

The alleged sender email address indicated in the header is redactedRealAttorney@Redacted-Real-Law-Firm.com. Probably spoofed at random and likely another stolen piece of identity. This person apparently actually exists and has a law firm according to an internet search.

The last hop before my ISP was… Received: from maui.mirahost.com ([75.126.255.131]) For the non geeks out there this means the last known place the message came from before my service provider got it. According to http://whatismyipaddress.com/ip/75.126.255.131 it is a server at Softlayer in Texas.
Before Softlayer it came from… Received: from Redacted-Real-Law-Firm.com (unknown [41.141.0.85]) The word “unknown” in there is another indication that the association of the domain Redacted-Real-Law-Firm.com with this address was not resolved by known legitimate DNS servers. Looking up the numeric address reveals (no surprise) that it resolves to Morocco, a low enforcement region for internet concerns http://whatismyipaddress.com/ip/41.141.0.85

Below is the message with an abridged full header…

Return-Path:
Received: from eastrmimpi109 ([68.230.240.49]) by RecipientISP.Redacted
(InterMail vM.8.01.05.15 201-2260-151-145-20131218) with ESMTP
id 20140627111709.YCVC18287.RecipientISP.Redatced@RecipientISP.Redacted
for redacted@redacted.com; Fri, 27 Jun 2014 07:17:09 -0400
Received: from maui.mirahost.com ([75.126.255.131])
by RecipientISP.redacted with
id KPH71o0052qsbMn01PH8tv; Fri, 27 Jun 2014 07:17:08 -0400
Message-Id: KPH71o0052qsbMn01PH8ua
Received: from maui.mirahost.com (unknown [127.0.0.1])
by maui.mirahost.com (Postfix) with ESMTP id B307993E286E;
Fri, 27 Jun 2014 11:17:00 +0000 (UTC)
Received: from Redacted-Real-Law-Firm.com (unknown [41.141.0.85])
by maui.mirahost.com (Postfix) with ESMTP;
Fri, 27 Jun 2014 11:17:00 +0000 (UTC)
Message-ID: <90cf96820dc5$315b9241$750189c6$@Redacted-Real-Law-Firm.com>
From: My CSA
Subject: from My CSA
Date: Thu, 27 Jun 2014 12:17:00 +0000
MIME-Version: 1.0
Content-Type: multipart/alternative;
boundary=”—-=_NextPart_000_B777_9B6157E3.01563C3F”
X-Mailer: iPad Mail (11D201)
Hi!

News: http://blog.carpediem.in/xxx/@@@@@@@.php

My CSA

In Conclusion: This is what they do these days. It’s a blended threat with a portion old fashioned Identity Theft, a bit of deception and social engineering. If you fall for it and your device isn’t protected and secure you may end up running a malicious application on your system before you know it.

1984 D.C. Johnson FAC-3

Posted on by

The box you see here is a 1984 D.C. Johnson FAC-3 designed to retrofit the European market version of the 1984 and 1985 Porsche 928. These cars were equipped with a Hotwire Mass Airflow Electronic Fuel Injection System known as LH Jetronic.

The D.C. Johnson FAC-3 is an Air/Fuel control unit that adds the closed loop Oxygen sensor feedback loop to Electronic Fuel Injection Systems not originally equipped with this feature. It was designed to retrofit cars built for sale in the European market before emissions regulations were instituted, to meet United States specifications after they were imported into the United States of America.

ENGINEER”S NOTE: One of my “Hobbies” is upkeep of the legacy of this product line created by my Father David C. Johnson. These devices were produced from 1981 through 1986. The company that marketed them (D.C. Johnson and Associates Inc.) was founded in late 1982 and was closed in August 1986. I created the website dc-johnson.com in 2008 after an inquiry into the availability of technical information. This led to the realization that there was an ongoing interest in maintaining theses products and the cars on which they are installed.

Vernon Johnson May 15, 2014.

More about dc-johnson.com.

Windows XP themes for Windows 8.1 (or Windows 7)

Posted on by

Since Microsoft has finally put an end to support of the most popular Operating System it ever made (Brilliant), the Computer User Community at large is less than enthused. Many users who became comfortable with Windows XP did not relish the idea of learning a new Desktop and navigation scheme (look and feel). So they just stuck with XP and never bothered with Windows Vista, Windows 7, or Windows 8/8.1. Are they now faced with a steep learning curve? Maybe, maybe not…

Did you know recreating a Windows XP look and feel is possible for Windows 7 or Windows 8/8.1?

While it requires a level of technical knowledge to do so, if you are fretting over what to do in a world without Windows XP, rest assured there is more than one way to make the desktop of the newer OS look a lot like Windows XP.

R.I.P. Windows XP

Posted on by

April 8, 2014:

R.I.P Windows XP

Today is the day that Microsoft officially pulled the plug on Windows XP…

While applauding Microsoft for the longevity of Windows XP is outside typical human nature, perhaps vilification of the company over it’s greatest Operating System success is a bit cliche as well. Windows XP has truly had a glorious run for a major revision of OS Kernel and User Interface. However, it’s not hard to agree that the business case for continuing to support it has faded to nothing. Microsoft has been warning the public for well over 7 years that they need to retire Windows XP and it is now over 2.5 years beyond the 10 years that was originally promised for support in the service terms document. Don’t get me wrong, I know many technical users who depend on Windows XP native applications for their livelihood. Applications that have never been updated to run on anything but Windows XP in many cases. Windows XP was the greatest, but the scales have tipped in the direction of liability. It’s time has passed.

So what is a dedicated Windows XP user to do? Well, my advice is fairly conservative.

  • Make sure all of the Security related patches (updates) have been installed.
  • Consider using a third party Antivirus progrm if you don’t already (just because Microsoft will quit updating Securty Essentials and Firewall for XP as well). Many Internet Service Providers (ISPs) supply one with the service at no extra charge, so use that if you can.
  • If you can afford it, get a new computer with a newer OS as soon as possible and start learning how to use it before retiring your Windows XP computer.
  • Most Important!!! Ifyou use Windows XP for banking, bill paying, or online shopping, STOP doing that as soon as possible!
  • Need more help? Click here.

R.I.P Windows XP

BTW: I use a variety of OS (while I use W7 most of the time, my current favorite OS X 10.8 Mountain Lion, also obsolete and superseded after 14 months can’t even run on a 32 bit CPU).

Moore’s Law and Data Storage

Posted on by

In 1987, A 10MB Hard Disk Drive for the 8 Bit IBM XT PC could be purchased for about $500.00, a steep decline in cost over the price when first introduced about 5 years earlier. Today, no current mass storage media with such a small capacity is produced. The smallest capacity for a USB Flash “Thumb Drive” sold these days is 1GB and they are under $10.00 in all but the most highly marked up locations, but why even bother when 16GB can be had for less than $10.00 just about anywhere too. But wait there’s more… A common reasonably priced capacity for these things today (February 2014) is 64GB at $30.00, so let’s use that for comparison.

Keep in mind that 1 GB is 1,000 MB, The 64GB USB Thumb Drive has 64,000 MB…

1987: 10MB HDD ~$500.00 = $50.00/MB.
2014: 64GB USB ~$30.00 = $0.00046875/MB (less 5 ten thousandths of a cent per Megabyte).

What does this mean? For this comparison the cost per MB “Megabyte” (1 Million Bytes) [1 Million units of 8 bit data] has decreased by a factor of more than 106,000.

How about a comparison of what you get for the same price? OK so the USB Thumb Drive comparison was chosen for both capacity and performance (Even though it’s about the lowest performing current product it’s still much faster than that old 1987 HDD). Then what does one get for ~$500.00 today? A 1TB SSD can be bought for ~$500.00. That’s 1,000 GB or 1,000,000 MB (it’s One Trillion Bytes). Cost comparison…

1987: 10MB HDD ~$500.00 = $50.00/MB.
2014: 1TB SSD ~$550.00 = $0.00000000055/MB (0.55 billionths of a cent per Megabyte).

As for performance? A comparison is difficult. The 1987 Hard Drive had an “Average Seek Time” of 85ms. The 2014 SSD does not have moving parts and “Seek Time” is largely irrelevant for the speed of electrons over a few mm distance. A more fair comparison is Data Transfer Rate…

1987: 10MB HDD 5MB/second.
2014: 1TB SSD 520MB/second.

Therefore, cost has dropped by about one Trillion percent and performance has increased by 10,400%.

Also the SSD is inherently durable while the old HDD was very fragile. Projected lifespan is measured in MTBF “Mean Time Before Failure” (a weighted average of the typical endurance of the product)…

1987: 10MB HDD 11,000 Hours (1.25 years) They actually typically lasted 10 to 15 years.
2014: 1TB SSD 1,500,000 Hours (171 Years).

In Summary: Most factors have been have been close to Moore’s law (Doubling in performance or capacity every 18 months) or a bit better, cost has dropped at a far more rapid pace than that!