Correcting a 2400 dpi A3 Scanner in Software

The VIISAN VF3240 is a 2400 dpi A3 flatbed scanner, sold under several names for a few hundred euros. Above 600 dpi, every scan has three defects, coming from the LEDs, from the motor, and from the sensor. vf3240 is an open source driver that talks to the scanner directly over USB and removes them. This article is about the three defects and how they are corrected. read more

UP9600: How to Bit-Bang 9600 Baud RS-232 on the C64

The user port of the Commodore 64 exposes a TTL-level RS-232 serial port that supports up to 1200 baud1. In 1997, Daniel Dallmann came up with a very sophisticated trick that allowed sending and receiving at 9600 baud2, using slightly different wiring and a dedicated driver. This “UP9600” wiring has become the de-facto standard for all modern accessories, like C64 WiFi modems. Let’s see how UP9600 works. read more

Xbox Serial Number Statistics

Slashdot had a story recently on how in 1942, the allies were able to estimate the number of German taks produced based on the serial numbers of the tanks. In 2010, a German hacker is doing the exact same thing with Xboxes. This article describes the generic approach, shows some results, and provides previously unreleased raw data of 14,000 Xbox serials so you can do your own statistics! read more

Playstation 3 Hacking – Linux Is Inevitable

In the talk “Why Silicon Security is still that hard” by Felix Domke at the 24th Chaos Communication Congress in 2007 (in which he described how he hacked the Xbox 360, and bushing had a cameo at the end explaining how they hacked the Wii), I had a little part, in which I argued that “Linux Is Inevitable”: If you lock down a system, it will eventually get hacked. In the light of the recent events happening with PlayStation 3 hacking, let’s revisit them. read more

How much change is in a vending machine?

There is only one way to find out – all you need is a giant pile of money and a vending machine that sells soda for $1.25: If you put in a dollar note and press the “return change” button, you will get the dollar note back directly. If you put in two dollar notes (the maximum it takes) at a time, it will give you change for the two dollars. read more