The Model A is the low-cost variant of the Raspberry Pi Model B.

The Raspberry Pi A wasn’t the first model. The Raspberry Pi Model B came out a year earlier, in February 2012, followed by the Model A in February 2013.

The model A purpose was to be cheaper, the first version costed about $25. They got to this price by making choices on hardware components: less USB ports and ram for example. But the Raspberry Pi 1 A remains interesting with these specifications:

• CPU: ARM1176JZF-S (ARMv6) Broadcom 2835 @700 MHz
• RAM: 256 Mo
• Only 1 USB port
• 8 GPIO pins
• HDMI, Audio and SD slot

In November 2014, they released an update (1 A+), with some changes on the hardware, mainly:

Raspberry Pi 1 model A+

It replaced the original Model A in November 2014. Compared to the 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 instead of 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.
• Jack audio output instead of RCA. The audio circuit incorporates a dedicated low-noise power supply.
• Smaller neater form factor. The USB connector was aligned with the board edge, moved composite video onto the 3.5mm jack, and added four squarely-placed mounting holes.
• 17 GPIO pins instead of 8

Model A+ is approximately 2cm shorter than the Model A.

The Raspberry Pi model A didn’t get a second version. They went directly to the version 3.

[Raspberry Pi Model A+](/assets/technical_documentation/pi2/Raspberry Pi Model A+.pdf)