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.

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.

1986VE91T: What's inside Russian ARM?

1986VE91T (1986ВЕ91Т in Russian) - is an ARM Cortex-M3 based microcontroller, designed by Russian company Milandr. It has 128 KiB of flash memory, 32 KiB of SRAM, hardware USB and 80Mhz core clock. Manufactured using 180nm technology with aluminum metalization.

As this chip was in ceramic package, no plastic etching was necessary - so all bonding wires are intact. Die size - 6.54x5.9 mm.


Read more on zeptobars.ru →

Growing copper nano™ crystals

By accident came across process of growing metallic copper crystals.

The technology is the following: put some CuSO4 in a tube, then some NaCl on the top, and add some concentrated solution of NaCl (using distilled water). Then put some iron inside - and wait few days/weeks. Initially, I've tried that with nickel - but it didn't worked. Obviously, tube must be sealed - otherwise solution would just evaporate and everything would be contaminated by NaCl crystals.

I've decided to try 3 variants: without extra salt, with 0.5 thickness of salt, and 1.5.

Loving C++11 syntactic sugar

Isn't that beautiful?

vector<Image> images;
images.emplace_back("i2.tif");//!!!
images.emplace_back("i1.tif");//!!!
for (auto& img : images)      //!!!
{
  //Do something
  img.edge(4);
  img.normalize();
  img.write( img.fileName() + ".debug.jpg" ); 
}

Life was so hard in pre-11 times...