The Raspberry Pi 1 Model A+ (A Plus) Is just 56mm long, 12mm thick and uses up to 45% less power than a Raspberry Pi 1 Model B+.
This newly updated version of the Model A does much more than simply bring it in line with the Raspberry Pi Model B+ - the Raspberry Pi Model A+ is the same dimensions as a HAT (Hardware Attached on Top) add-on board and can run at nearly half the power consumption as the Model B+.
Compared to the original Model A it has:
More GPIO pins. The GPIO header has grown to 40 pins, while retaining the same pinout for the first 26 pins as the Model A and B.
Micro SD. The old friction-fit SD card socket has been replaced with a much nicer push-push micro SD version.
Lower power consumption. By replacing linear regulators with switching ones we’ve reduced power consumption by between 0.5W and 1W.
Better audio. The audio circuit incorporates a dedicated low-noise power supply.
Smaller neater form factor. We’ve aligned the USB connector with the board edge, moved composite video onto the 3.5mm jack, and added four squarely-placed mounting holes. Model A+ is approximately 2cm shorter than the Model A.