Pem’s Tech Blog

http://db.tt/lPEYCPsn – if you join using this DropBox referral link, we both get 500 MB extra free space for the free version of DropBox.  DropBox is a very simple convenient (and free) way to backup and access and (optionally) share your files over the internet.

Free version is 2 GB (plus up to 16 GB extra from referrals), and the internet has limited bandwidth, so obviously it’s not meant for huge files.

Might be some security concerns for private files, so encrypt private files (consider 7zip or TrueCrypt), or don’t put them in your DropBox folder.

Pem (Admin) :: 2012/04/08 (Sunday, April 8, 2012) :: Computers / Tech, Internet / Web :: No Comments »

This is the previous gen Mac Mini, not the 2010 or 2011 version.  If I wanted to throw money around, I’d probably get a current gen Mac Mini (with AMD Radeon HD 6630M).  But instead, I’m just upgrading the hard drive.  I had this on my list to figure out for a while, but I’ve now finally gone through with it!

Hardware:
I started with one internal hard drive (120 GB), one external FireWire hard drive (1.5 TB), and an optical drive.  I replaced the 120 GB drive with a new 750 GB 7200 rpm drive, and I replaced the optical drive with the old 120 GB drive.  I used a nifty (but overpriced) enclosure from ifixit.com for replacing the optical drive.  This enclosure also made the “6-pin to 15-pin SATA connector” cable (described in one of their tutorials to give the Mac Mini A1283 two hard drives) unnecessary.  I pretty much just followed a photo-based guide from ifixit.com:

http://www.ifixit.com/Device/Mac_mini_Model_A1283#deviceGuides

http://www.ifixit.com/Apple-Parts/12-7-mm-SATA-Optical-Bay-SATA-Hard-Drive-Enclosure/IF107-081

I had taken apart the Mac Mini once before, to upgrade the RAM to 4 GB, so although it’s kind of a pain (especially the first step of opening it) and took a long time, it wasn’t that bad, and luckily I didn’t break anything.

Software:
Before opening the Mac Mini, I did the initial software part.  I used SuperDuper to make a backup of my 120 GB boot drive to my 1.5 TB FireWire drive. The FireWire drive has two partitions (using Disk Utility) – one for SuperDuper and one for Time Machine.  I verified I could boot from my SuperDuper backup on the FireWire drive (you hold down Option during boot to select boot device).  Then I opened the Mac Mini and did the hardware part.

When I was done with the hardware part, everything worked happily, and I used SuperDuper to move the FireWire backup to the new 750 GB drive…  Except, it was still by default booting from the 120 GB drive.  And for some reason it wouldn’t let me use Disk Utility to Erase the 120 GB drive.  Of course you’d expect that when you boot from the 120 GB drive…  But Disk Utility wouldn’t let me Erase the 120 GB drive even when I booted from the 750 GB drive or from the SuperDuper FireWire backup!

Eventually I figured out that the normal workaround is to boot to the install disc.  Since I’d just removed the DVD drive, I ended up using remote disc to my primary computer (my giant Windows desktop with a Blu-ray optical drive).  So I used DVD sharing and Remote Install to use my Windows computer’s optical drive from the Mac Mini during startup.

You hold Option when booting the Mac Mini to get to the boot menu.  While in the boot menu, you can connect to the LAN over WiFi (assuming you aren’t already connected via Ethernet).  On Windows, install Apple’s DVD Sharing and run Remote Install from the DVD (or setup.exe).  Back on the Mac Mini, I picked the Mac OS install DVD (Snow Leopard since I didn’t have a physical disc from the Lion upgrade).  Then, when inside the install disc menu, instead of installing, you pick Disk Utility from the menu, and I was able to Erase the old 120 GB drive from there.  When I exited the install disk, it asked which drive to make my boot drive, and I of course picked the new 750 GB one.

Outro
And everything was now working as expected.  I might later replace the 120 GB drive with a second 750 GB 7200 rpm drive, or even an SSD drive…  But if I do, I’ll probably wait a while (maybe a year).  For spending time on stuff like this, I have other ideas, such as set up Mac Mini as a common area media center for elliptical, or set up a third computer as a dedicated Linux box to use for code etc.

Pem (Admin) :: 2011/11/26 (Saturday, November 26, 2011) :: Computers / Tech, Mac OS :: No Comments »

Plan – make two separate blogs:
1) Pem Tech blog is about anything: opinions / philosophy, computer tips, whatever
2) Pem Code blog is about programming, and nothing else; anything else, even general computer stuff or general game stuff, goes on the other blog; this way, my code stuff stays here

My intent is to put useful programming related stuff in Pem Code blog.  Then if for some reason I have a senseless urge to post random stuff, I can put that on Pem Tech blog.  So the Pem Code blog is intended to be useful code stuff, notes for learning, and potentially related to resume (CV), for non-work hobby-project self-learning programmer examples.  In other words, Pem Tech blog isn’t really work-related or programmer-related, but Pem Code blog is.

There may be some areas of confusion, such as where do I put a computer bug fix thing?  If it’s not a code thing, then it goes in Pem Tech blog.  What about little scripts for AutoHotKey?  I think that’s a code thing, so Pem Code blog.

Another example of gray area is details on the parts I picked for my build-it-yourself computer.  This is sort of career-related, since it shows interest and literacy in higher level hardware stuff, and as of 2011/10/23, I work on a full system simulator (functional simulation, GPU simulation).  But, in the end, that’s not really code, so maybe it should go in Pem Tech blog.

Another example of a gray area is this post itself.  Since it rambles and doesn’t focus on (teaching / explaining, or showing off) a programming thing, I’ll keep this post here, in Pem Tech blog.  In other words, even though this post is about Pem’s Code Blog, it’s a rambling post that adds clutter, so this rambling clutter post can go here on Pem’s Tech Blog.

Examples of what would go on Pem’s Code Blog?  Notes on the Computer Science class videos I’m currently watching (Stanford intro Computer Science, Harvard intro Computer Graphics, Khan Academy Math and Physics).  Notes from the papers or books I’m studying (GPU papers, GPU doc, DirectX / OpenGL doc, Essential Math for Games and Interactive Applications book, GRE Computer Science).  Notes on something I learned for work, such as C++ and OO related or GPU related.

Since I already take a lot of notes in my daily life (for work and for learning) on Paper, in OneNote, in EverNote, in code comments, etc…  Pem’s Code Blog will be one more place for me to put notes.  Hopefully, if do end up putting many posts on Pem’s Code Blog, it will be concise and useful and well-organized.

As of 2011/10/23, Pem’s Code Blog is empty.  I installed WordPress, but I didn’t setup a theme yet, and I didn’t write the first post yet.  However, I did just get off the elliptical.  I did around 370+ calories of exercise while watching a Harvard Extensions School Computer Graphics class from iTunes U, which had some great review info.  I took some notes, and those notes are an example of something I might post on Pem’s Code Blog.

See Pem’s Code Blog

Pem (Admin) :: 2011/10/24 (Monday, October 24, 2011) :: Blogging, Computers / Tech :: No Comments »

Pem’s Tech Blog was an excuse to play a little with another set of web tools (ie, WordPress blogs).  I had lots more ideas of things I’d ramble (or rant) about here…  Such as more Magic:TCG vocab, Philosophy related, computers and STEM related, and other random stuff.

Without even spending that much time on this, I got an idea of how huge a time sink maintaining a blog and writing entries can be.  Doing your own WordPress setup via shared web hosting adds to that time consumption – though obviously not as bad as if I ran my own dedicated server’s OS, PHP, SQL, etc.

I also got some more exposure to a particular kind of writing.  For the type of writing I do in these posts and in emails…  I think it’s different than the kind of writing they like to see for Liberal Arts classes or GRE essays.  Ie, proper grammar and full sentences and eloquent verbose writing styles are bad, or at least less important.  The important thing is efficient meaningful concise useful communication.  A good engineer type email likes to be concise and contain a high information content per word count.  At least for the intro paragraph.  Then you can attach or append something more verbose, or imply to discuss further in person or if they ask for more detail via email.  That’s the type of efficient concise communication I’d like to focus on with emails and blogs.  At least for the initial intro paragraphs, or for quick reference info posts.

I might still put some occasional rambling here…  But I think a more productive thing would be that if I do any more blog posts, they should be stuff like notes related to Programming.  Ie, a work project, a side project, or a study/learning aside.  For this purpose, I am creating a separate Pem’s Code Blog, see ../pemcode

Pem (Admin) :: 2011/10/23 (Sunday, October 23, 2011) :: Blogging, Computers / Tech :: No Comments »

Sometimes the ability to copy/paste between my local computer and remote computer breaks when I use Windows Remote Desktop Connection.  The simple fix is:

1) on the remote computer, use Task Manager to kill rdclip.exe
2) close your RDC session
3) re-open your RDC session

The reason apparently has something to do with certain applications not passing the clipboard messages around the way Windows requires (do an internet search if you want to know more).

I ran into a similar issue when with TightVNC on Windows to a Linux vncserver.  I was able to connect, but the clipboard didn’t work.  After I ran “vncconfig”, the clipboard worked.

Pem (Admin) :: 2011/07/26 (Tuesday, July 26, 2011) :: Linux, Windows OS :: No Comments »

I recently built a desktop computer (from parts).  Warning, it’s been up and running for at least a few weeks, so some of the parts may already be outdated.  The most obvious change is that AMD will soon be releasing Bulldozer CPU’s.  However, there’s always better hardware coming out…  And I didn’t want to put it off any longer (my old computer was really falling apart, and becoming a distraction / liability).

Parts:
* HAF 932 AMD Edition (AMD Fusion dragon computer case), $160
* Corsair AX1200, $280 minus $10 mail-in rebate
* Asus Crosshair IV Formula, $215 on newegg.com
* CPU cooler, Thermalright Silver Arrow, $90, amazon.com
* CPU, AMD Phenom II X6, Socket AM3, $200 for 3.2 ghz, minus $50 rebate
* GPU, Asus DirectCU II Radeon HD 6970, oversized and overpriced, but less loud than other 6970′s, $400 minus $60 rebate
* DDR3 memory x 16 GB (4 GB x 4 slots) ($300, overpriced)
* Optical Drive with Blu-ray, $110 on newegg.com
* HDD, WD Caviar Black, $170 on newegg.com

Total: 160 + 270 + 215 + 170 + 90 + 150 + 340 + 300 + 110 = $1805

Extras (which put it over $2000):
* air filters to reduce dust
* extra case fan, reversed 3 of 4 fans to create negative air pressure
* extra hdd’s, including a very expensive and very fast SSD, 240 GB OCZ Vertex 3

Reuse: I reused my KVM, keyboard, mouse, monitor, speakers, furniture. I got a new mouse pad shortly about a month after the computer was setup (Razor Ironclad), b/c the paint on my desk (which is made of particle board) is bumpy and erratic.  If I get anything else for the computer in the next year (12 months or so), it probably won’t be anything expensive.

Goals affecting hardware choices – high performance & stability, less noise
I didn’t get workstation hardware (you could easily spend over $5,000), and I got an AMD CPU (at the time of writing, the Phenom II X6 costs significantly less than an equivalent Intel Core i7).  But other than that, cost was not a significant factor.  In case it’s not obvious, this is very much an AMD computer (AMD CPU, AMD GPU, and AMD chipsets on the motherboard).

A primary goal was to have reasonably high cooling (and stability), but with significantly less noise than my old computer.  Bigger fans typically means less noise per airflow (CFM).  This goal influenced my choices for almost every component.

In some cases, I picked a component with lower performance, not due to the price, but due to my concerns about noise.  Example, the Asus Crosshair IV Extreme is higher end than the Asus Crosshair IV Formula, but it has an annoying tiny/loud chipset fan.  Example, the 6990 (at the time of writing) only had a reference version, which had a much louder fan.

I also decided to go with (negative air pressure) and (dust filters) to reduce dust.  The dust filters are DemciFlex, which are magnetic, and custom size/shape.  Only my case’s front fan is an exhaust fan.  The rest are intake fans.  This is to create negative air pressure (to reduce dust).

I also wanted a better (cleaner, neater, bigger) case, with better cable management and big fans (low noise but high airflow).  I decided on the AMD Edition of the HAF 932.  The standard HAF 932 has a big fan on the side, but the AMD Edition replaces the fan with a bigger window, with an AMD Fusion dragon logo on it.  I’m not sure if I would normally trade a big fan for a bigger window.  But, I do like the big window (and AMD theme).

Pem (Admin) :: 2011/05/15 (Sunday, May 15, 2011) :: Computers / Tech, Hardware :: 1 Comment »

I have some really old DDR memory from Crucial (years old).  It recently broke, and I heard Crucial has a lifetime warranty on it.  I got it directly from their website, crucial.com.  And I submit an RMA request to replace the 1 GB stick, for free, also from crucial.com.  It sent me an address label and RMA paper to print.  I put them in a regular envelope with a 42 cent USPS stamp on it, and put it in the USPS box.  They sent me the replacement, with no additional hassle.  I didn’t have to call them on the phone even once, or keep track of some years old warranty paper or number.  Pretty low hassle, especially since the broken RAM fit in an envelope.

Somewhere in the RMA papers, I think it said to put it in the original package, so I was worried they wouldn’t accept it in a plain standard envelope…  Fortunately, they sent me the replacement anyway.

I more recently got some DDR3 from newegg.com, branded G.Skill.  If it breaks, I just hope it’s as easy to RMA as that 1 GB DDR stick from crucial.com.  If not, then I’ll regret getting (G.Skill from newegg.com) rather than (Crucial from crucial.com).

Pem (Admin) :: 2011/05/01 (Sunday, May 1, 2011) :: Computers / Tech, Hardware :: No Comments »

I had a strange device driver conflict with my newer GPU (Radeon HD 4850) on Windows 7 and my old motherboard (MSI MS-7184, aka HP AmethystM-GL6E) (see here).  After recently installing the latest ATI GPU drivers, I noticed that the High Definition Audio Controller got re-enabled whenever I reboot Windows 7.  So, I investigated an automated way to disable it after the reboot.

I tried doing it with AutoHotKey, but the GUI scripting wasn’t working for Device Manager.  So instead, I looked into a command line version of Device Manager called devcon.  I had better luck with devcon.  So, I ended up putting a simple one line batch (*.bat) script in my startup folder:

devcon\amd64\devcon.exe disable find *DEV_AA30

How did I figure out the “*DEV_AA30” part?  “devcon.exe find *” listed all the devices, one of which was High Definition Audio Controller with the ID “PCI\VEN_1002&DEV_AA30&SUBSYS_AA301002&REV_00\4&3083E1D6&0&0110”.  Using that ID directly got multiple matches (something weird with the & symbols?).  But I figured out that doing “devcon find *DEV_AA30” only matched one device.

Pem (Admin) :: 2011/04/10 (Sunday, April 10, 2011) :: Windows OS :: No Comments »

For a period of time, I had begun to feel like mobile AMD CPU’s were having trouble competing with mobile Intel CPU’s (I’m specifically talking about mobile, not desktop, not server / workstation).  For example, I had some worries about if there might be a higher likelihood of heat problems (and battery life).  However, the Fusion APU’s completely change that.  laptopmag.com gave the HP Pavilian dm1z with Fusion APU an editor’s choice, and said, “Despite its small size, the dm1z is one of the coolest notebooks we’ve yet tested” and “blows past Atom-based netbooks while providing enough endurance to see you through the day”.  As mobile x86 CPUs and APUs allow smaller devices with low heat and all day battery life…  It might turn out that eventually the ARM tablets (iPad etc) turn out to be a fad.

Pem (Admin) :: 2011/01/23 (Sunday, January 23, 2011) :: Computers / Tech, Hardware, Mobility :: No Comments »

Each channel is 6 MHz.  2 says early systems 200 MHz (33 channels), now up to 550 MHz (91 channels).  But 2 seems old (maybe year 2000?), and 5 shows up to 1000 MHz bandwidth.  2 says post-1989, digital cable and mpeg compression allowed 10 TV channels on a single 6 MHz bandwidth analog channel.  Digital Cable also allowed them to use encryption (instead of just simple scrambling) (also allows more data).  Of course in 2011, we have HDTV and also better video compression.

1 says we share a single CMTS with our neighbors, possibly 4,000 to 150,000+ cable modems.  The CMTS (cable modem termination system) connects coaxial connections to the internet via ethernet interfaces, which is HFC (hybrid fiber coax).

1 claims our internet upstream is a single 2 MHz channel, and our download goes over a single 6 MHz channel…  Shared with hundreds of neighbors!  The upstream is time-shared.  While the downstream is just shared.  My interpretation is, we share a single wire with hundreds of neighbors, with a bandwidth of 0 to 1000 MHz.  Most of this wire is used to send everyone the same TV channels (ie, we get every channel, but to view it we need a TV box that decrypts the channels that we subscribe to).  We time-share (with hundreds of neighbors) a single 2 MHz band for uploads.  We use a single 6 MHz channel for download, shared with hundreds of neighbors.  So everything our neighbors download, we also download.  The only thing that stops us from seeing our neighbors’ downloads is encryption, and the fact that our cable modem filters out the packets that don’t have our cable modem’s address on it.

1 seems to be from 2000 (ie, 11 years old).  It does mention that the cable provider can decide to add a new channel for internet, and split the base of users that share that channel.  So this could mean that even if our shared wire covers 1000 people, that could be split into 100 people over 60 MHz.  So, our internet might be on the 900 MHz band, shared with 100 neighbors.  Plus, on the 906 MHz band, is another different 100 neighbors’ internet connection.  etc

Because our connection is shared with lots of neighbors, they throttle our connection based on usage, and in some locations are considering per-user bandwidth caps.

If it were up to me, I would say 1000 / 6 = 166 channels, so we should just ditch the cable TV channels, and dedicate them all to internet downloads!  However, there’s probably other factors to consider beyond my simplistic internet-greedy preferences O:-)

Economics: sending everyone the same TV channels is an efficient way to send lots of video data.  They can also keep the price of internet lower, by separately selling the cable TV bandwidth (and phone line bandwidth).

Bottleneck: There might be a bottleneck somewhere else, such as the CMTS.  I’m totally speculating on this.

Finally, keep in mind that I think the articles I read (1, 2) were from 2000, and a lot might have changed since then.  So maybe in 2011, more of the 6 MHz channels are dedicated to internet?  I’d be curious to find out more.

Links:
1. http://www.howstuffworks.com/cable-modem.htm/printable
2. http://electronics.howstuffworks.com/cable-tv.htm
3. http://www.linktionary.com/c/cabledata.html
4. http://en.wikipedia.org/wiki/Cable_modem_termination_system
5. http://en.wikipedia.org/wiki/North_American_cable_television_frequencies
6. http://en.wikipedia.org/wiki/Bandwidth_throttling
7. http://en.wikipedia.org/wiki/Bandwidth_cap
8. http://lifehacker.com/5215011/which-is-worse-bandwidth-caps-or-throttling

Pem (Admin) :: 2011/01/23 (Sunday, January 23, 2011) :: Computers / Tech, Internet / Web :: No Comments »