Jetson Nano – basic specs


Here are some really rough notes on the Jetson Nano, including specifications. This was my first look at the Jetson Nano, when I was first discovering its potential.

The Jetson Nano is a System on a Module (SOM) combined with a carrier board. There are two versions: 2GB and 4 GB. There are two varieties of the 4GB dev kit carrier board: A02 and B01

For more information, see Swapping the dev boards below.

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Low or High Density?


I need some (4 x 4 GB) memory DDR2-800 (or DDR-667) PC2-6400u (or PC2-5300) UDIMMS Unbuffered Non-EEC for an AMD Althon Dual Core 4850e motherboard.

From DDR2 PC2-6400U 800Mhz, high density are not recommended.

If you google a particular memory stick identifier, you can end up with different looking sticks (126 or 32 ICs)

So how to tell low density from high density?

Continue reading Low or High Density?



After watching The Gigatron TTL Computer without a Microprocessor, I got to thinking about building an Apple I (or II). After a quick search I found the Wikipedia entry for the Replica 1 (see this Apple 1 kit page), and from there the Apple II section of ReactiveMicro’s site, and the apple-ii-rev-0 board.

Then I came across loads of retro teardowns from EEVblog

Continue reading Retro!

Noisey chips


Following on from Banging noises…, I attempted to recreate the Noise Chip (U4) depicted in the LDB-1 schematic, from the article Anatomy of a drum machine. The noise chip creates both a white noise signal as well as four tuned square waves at different (unknown) frequencies. I have attempted to contact the author for more details but have not had a reply as yet.

It is using either PIC (which is likely seeing as the author states a preference for the PIC microcontrollers), or an ATtiny.  I will attempt to use a ATtiny/ATmega microcontroller (specifically ATmega48P/88P/168P/328P but the code should compile for most Arduinos).

Note that parts of this are a work in progress.

Note: The phase-correct 50% trick is possible with Timer0 on an ATtiny85, but it is not clear if it is possible with Timer1 (although Timer0 does have two channels). Atmel AVR ATtiny comparison chart

Continue reading Noisey chips