Few words about me:

From very childhood I loved computers, electronics, lasers, sulfuric acid and liquid nitrogen. I always wanted to be making microchips, UAVs and see nuclear explosion.

Now I am doing software engineering and in the spare time - some microelectronics and physics/chemistry experiments.

I live and work in Russia, Moscow.

Microscope photos of Avalon - specialized Bitcoin processor

Yifu Guo (designer of Avalon) agreed to send me several chips for decapsulation, but while they were slowly traveling around the world - needbmw gave me damaged chip from his Avalon bitcoin mining unit.

Damaged chip itself (fortunately, die itself is not damaged):
This tiny thing does 282 Mhash/s (like AMD 6970 videocard), consuming ~2.5W of power.


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Technopolis "Moscow"

Visited Technopolis "Moscow". It is like "Skolkovo" for high-volume manufacturing - it offers lower taxes (0% property tax, 15.5% profit tax instead of 20%), simplified customs bureaucracy and huge area (220'000 m²) left after car manufacturing plant ("Moskvich").

This is how it looked before reconstruction:

House mosquito(?) walking on microscope stage

After photo session it was released to the wild - to breath fresh air and eat humans.

BarsFA - 4-transistor full adder

For my transistor-computer project (which is already going for 3 years) I needed compact implementations for most of common digital blocks, and full adder - is one of the most important among these.

Canonical implementation of CMOS full adder takes 28 transistors:


Modern implementations using transmission gate and number of tricks reduce this number down to 8-11, with more strict requirements for transistor selection. These schemes usually could not be used with discrete transistors, as they use 4-terminal transistors, and suffer from degradation of logical 1 level, which becomes even more severe with discrete transistors as they have Vt=1.5-2 compared to ~0.5V for integrated transistors.

The smallest full adder I've seen was using 6 transistors and capacitors at inputs - but I am not sure how to make it work reliable in real-world. Known implementation using bipolar transistors - also using 22 transistors.

But can you make it using only 4 transistors? After thinking and trying few variants, i've got the following schematic working:

Orange Corsair M90

Now I own True exclusive orange edition of Corsair M90 Initially it was looking like this.