Bitcoin Mining: Raspberry Pi with a Altera DE0-Nano FPGA

A small but fascinating christmas present was the credit-card sized Raspberry Pi microcomputer. Paired with Altera's DE0-Nano FPGA, Bitcoin mining came to mind. Investing a little time into the future of virtual currencies, some pocket change may come handy for my daughters future life. It quickly turns out that the market is owned by professionals with deep pockets and specialised large-scale mining hardware, small-scale hobbyists are out. [see picture]

Embedded CPU Module: LCD on a Digi RabbitCore RCM4010

HD44780 Logo Rabbit Logo
Following up to the previous description how to connect a HD44780 LCD display to Rabbit RCM3720, only small changes are needed for building a similar LCD connection to a RCM4010 board. We will also look into creating "custom" characters for pseudo graphics with character LCDs.

[read article]

Embedded CPU Module: LCD on a Digi RabbitCore RCM3720

HD44780 Logo Rabbit Logo
In 2008 I upgraded from a old BL1800 Jackrabbit system. The new Rabbit systems Ethernet Connection kit features the newer and more powerful RCM3720 Core, plus network.

The old BL1800 (picture) had been running with a serialized 2x16 LCD display BPI-216 from Parallax, which needed only 3 wires in total. I could not find one easily in Japan, so I looked at the many parallel port LCD displays. The RCM3720 has plenty of ports, so I got a HD44780-compatible type. It turned out that the parallel-port LCD was much more difficult to connect and to program, googling around didn't help much.

After working out the correct wiring and programming, I share the knowledge to save others trouble and time. This guide works with a RCM3720 RabbitCore Ethernet Development kit, using the supplied development board and a Sunlike SC1602BSLB 2x16 LCD display. [read article]

Linux Cluster for High Performance Computing

How to build a diskless Linux Cluster
I have been fascinated by clusters since 1995, when DEC VMS clusters where state-of-the-art and first Windows clusters emerged for simple storage sharing. Almost a decade later, cluster technology becomes mainstream through Linux, with falling hardware prices making it affordable for "home" use. What could I use a cluster for? Finally start my education in 3D Graphics Rendering and Computer Art Design? Donate power to SETI? Compute rainbow tables and check out new ways of crunching passwords? [read article]

Keeping Time with NTP and a WWVB Radio Receiver

Setup a NTP time source
Almost everything in modern computers relates in some way to time: CPU cycles, bus frequencies, graphics refresh rates, file dates, even a simple cursor blink. Correct time is fundamental for reliable and secure computing. Yet setting and keeping correct time is one of the challenges standard computers didn't solve yet. Computer time happily drifts away and relies on the user to be set, while any cheap digital watch keeps better time when radio synchronized to a public time service. But there is help out there, NTP [read article]