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hillhacks

Hacking Hacking and Making in the Himalayas

hillhacks Workshop Tools Part 1: Scavenging for PCs

From the time we first conceived of hillhacks, the goal was to have something tangible where people can learn and do rather than just sitting in a chair absorbing words. We all agreed that a focus on hands on workshops was essential so I've been spending the last ten months putting together tools so that people can actually get their hands dirty and do something.

One of the most important sets of tools I had the good fortune of finding was a large stash of cheap, identical PCs. This happened early and it was a stroke of luck that I stumbled on them. I spend a lot of time in Akihabara in Tokyo and one of my favorite things to do is browse the junk bins for old or broken equipment that people no longer want. One of my favorite shops is called PC-Net which sells used PCs. In the back of the shop, they have a bunch of boxes for computers that they deem un-sellable. These PCs are either too old, in poor condition, or have something obviously wrong with them.

My friend told me that PC-Net had recently got a new shipment of junk laptops and they were all identical for about $25/each. I rushed over to PC-Net and I immediately realized the value of this find. Having a workshop set of identical laptops is a holy grail and allows workshops to be run smoothly with much fewer unknowns since software compatibility issues can pretty much be removed from the equation. This leads to much more efficiently run workshops where the time can be focused on learning rather than troubleshooting. Also, we could keep this set of laptops in Dharamsala where they can be checked out by the community for other workshops or events. Having a community-owned workshop set of identical laptops would be huge win for everyone.

The laptops were used Lenovo Thinkpad X61 notebook PCs with a Core2Duo processor. They came without RAM, HDD, or power supplies, though so that was one hurdle. The second hurdle was that they came in an unusable condition. Each of the PCs were likely liquidated from some company that was getting rid of all their old laptops. They came with the BIOS and boot password protected by the former IT admin and nobody at the shop knew the password. Since they essentially could not get past the boot login screen, they were considered junk. However everything else was functional and I could verify that the LCDs and keyboards worked properly.

The next step was to figure out how to crack off the security password so that the machines could be usable. This basically meant figuring out the supervisor password to get into the BIOS and removing the protections. I should mention here that since I owned these machines, this is all perfectly legal. There are some standard tricks to getting into the BIOS such as removing power to the CMOS (battery backed SRAM) to clear the settings or certain maintenance key combos that act as a universal reset. Unfortunately these didn't work. Lenovo actually has a dedicated EEPROM which retains its settings even after power is removed and stores the supervisor password and other info in encrypted form.

After trying out various techniques, I found one that worked. For this particular laptop, you had to open it up and expose the motherboard. After that, it required removing a modem board to get to the security EEPROM. Once the EEPROM was exposed, there was a technique where you had to turn on the PC, hit the ThinkVantage button to go into BIOS, and then immediately short the I2C pins (SDA and SCL) on the EEPROM with tweezers. This would cause the security software to crash and allow access into the BIOS. Although it doesn't give up the supervisor password, the BIOS access allows you to go in and remove all the security protections.

Once I was able to do this successfully on two laptops, I purchased an additional 40 laptops and had them shipped to my farm in the countryside. These laptops would form the basis of the hands-on security and art/technology programming workshops for both adults and children. They're extremely valuable because they are all identical laptops which eases maintenance and IT support. It's possible to keep a series of stock hard drive images for various workshops and roll out cloned, identical images for all the PCs. It's also easier to verify that software will work with no compatibility issues before a workshop since this is also a major frustration when tons of different PCs with different OSes and configurations are in a workshop.

After acquiring the laptops, 45 when all's said and done, the next obstacle is to acquire the various missing parts for them. They still required RAM, HDDs, and power supplies. The Lenovo X61s require PC2-5300 RAM which is an outdated RAM technology. Sourcing RAM through standard channels would be expensive since they're considered a rare type. I needed quite a bit and hit the Akihabara back street junk bins. I located a shop that stocked PC2-5300 512 MB RAM sticks in SO-DIMM form for $2/each. I cleaned out their stock and still needed more RAM. I also sourced bulk RAM from eBay and various other sources. Eventually, I was able to assemble enough RAM to populate each laptop with at least 1 GB RAM. This would safely run an Ubuntu Linux installation.

I pretty much had to do the same thing with the HDDs which was piece them together from various sources. I mainly stocked 40 to 60 GB HDDs from junk shops that were salvaged. For workshops, HDD reliability wasn't a huge issue since data loss wouldn't be catastrophic. The HDDs typically ran $6 to $10 each. I got some donations of 500 GB HDDs that were unusable. They used a technology called Advanced Format (AF) to increase the sector size from 512 bytes to 4096 bytes. This caused havoc on the X61s and took me awhile to figure out why they wouldn't boot with the big HDDs.

Finally, procuring the power supplies is kind of an interesting story. Lenovo uses a special three terminal power supply, where standard power supplies are two terminal (power and ground). The third terminal is mainly to identify the power supply and is likely used by the power management software or charging circuitry. The used supplies are in high demand because new supplies are expensive. Used ones are also a bit expensive at ~$16/each. I bought a few just so I could have known good test supplies. After that, I ordered a bulk shipment of Lenovo Thinkpad knockoff supplies from China for around $7 each. I'll be checking these supplies on my oscilloscope to investigate the output voltage and stability. If these are okay, then I'll be shipping the PCs as complete units out to Dharamsala for hillhacks. Overall, each laptop's final cost is about $50, still a huge bargain considering all the possibilities they enable.

As you can see, this is just the first part of the workshop tool procurement for hillhacks but its already been quite an interesting challenge and adventure. I'll be keeping everyone updated on the laptop progress and the next few parts will detail the stories behind the other tools for the workshops we'll be having at hillhacks.

Stay tuned!

Akiba

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