Fortunately I got very recent ATmel MCU ATtiny102 and quickly tried to program RGB LED blinking through ATmel Studio. I found several differences from conventional 8-pin AVRs in every aspect.

So far, 8-pin AVR was programmed by SPI (MOSI/MISO/CLK/RESET..) but this new 102 accept only TPI, which is same as ATtiny10.

(2) Pin assign is completely different!!!

As shown in the above picture ATtiny102 (up) has 1-pin VCC and 8-pin GND. This is totally different from conventional pin assign (which was totally pin compatible in 8-pin AVR series, ATtiny 13 to 85). We need a bit care for initial prototyping test.

(3) New 102 has two output ports PORTA and PORTB

I guess, ATmel uses same chip for 102 and 104 (simply most of ports are not wired in 102) and as a result 102 has two ports. This means, little source modification is required from conventional 8-pin AVR to 102.

(4) Additional voltage reference (1.1 V, 2.2 V, 4.3 V) for A/D converter

Voltage reference can be selected by REFS1 and REFS0 in ADMUX. Some ATtiny has 1.1 and 2.56 V reference but they has some limitation, requiring external capacitor. But the case of 102/104, it is completely free of charge.

(5) USART and USARTSPI (functions exclusive) supported

Not bit-banged but serial and SPI (one of them) are supported..

As for programming, ATmel Studio has already supported ATtiny102/104 and we don't need to wait for something.

Actual operation can be found in the following movie...