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Raspberry Pi 1 Model B specs, pinout & datasheets

Single-board computer · Raspberry Pi · Released February 2012

The board that started it all: a $35 Linux computer the size of a credit card, launched in February 2012 with 256 MB of RAM and doubled to 512 MB that October.

Raspberry Pi 1 Model B
Photo: Tors, CC BY-SA 3.0, via Wikimedia Commons
CPU
Arm1176JZF-S (ARMv6), single core
Clock
700 MHz
RAM
256 MB; 512 MB from October 2012
Storage
Full-size SD card
I/O voltage
3.3 V
Released
February 2012
Status
Retired

Specs checked against the cited sources on 1 October 2026 (AI-assisted source check). Spotted a mistake? Use the form at the end of the page.

Specifications

14 specs
Chip / SoC
Broadcom BCM2835[1]
CPU
Arm1176JZF-S (ARMv6), single core[5]
Clock
700 MHz[5]
RAM
256 MB; 512 MB from October 2012[1]
Storage
Full-size SD card[1]
GPIO
26-pin header (P1)[1]
I/O voltage
3.3 V[2]
Input voltage
5 V via micro-USB[1]
Ethernet
100 Mb/s[1]
USB
2 × USB 2.0[1]
Video
HDMI and RCA composite; DSI display connector[1]
Expansion
CSI camera connector[1]
Dimensions
85.6 × 56.5 mm[5]
Launch price
US$35[5]

Can I still use it?

1 platforms
Raspberry Pi OS
Supported[6]32-bit image; the 64-bit image needs a 64-bit model such as the Pi 3 or later.

As published by each project, checked weekly. A platform not listed has no published information here, which is not the same as no support.

Datasheets and documents

2 documents

Pinout

26 pins
Raspberry Pi 26-pin GPIO header (P1, revision 2) pinout diagramP1 (26-pin GPIO)13V325V3GPIO245V5GPIO36GND7GPIO48GPIO149GND10GPIO1511GPIO1712GPIO1813GPIO2714GND15GPIO2216GPIO23173V318GPIO2419GPIO1020GND21GPIO922GPIO2523GPIO1124GPIO825GND26GPIO7
Raspberry Pi 26-pin GPIO header (P1, revision 2)[2]. Revision 2 numbering shown
  • Power
  • Ground
  • GPIO
  • Special
  • Not connected
Pin table (26 pins)
P1 (26-pin GPIO)
PinLabelKindFunctions
13V3Power
25VPower
3GPIO2GPIOI2C1 SDA
45VPower
5GPIO3GPIOI2C1 SCL
6GNDGround
7GPIO4GPIOGPCLK0
8GPIO14GPIOUART TXD
9GNDGround
10GPIO15GPIOUART RXD
11GPIO17GPIO
12GPIO18GPIOPCM CLK, PWM0
13GPIO27GPIO
14GNDGround
15GPIO22GPIO
16GPIO23GPIO
173V3Power
18GPIO24GPIO
19GPIO10GPIOSPI0 MOSI
20GNDGround
21GPIO9GPIOSPI0 MISO
22GPIO25GPIO
23GPIO11GPIOSPI0 SCLK
24GPIO8GPIOSPI0 CE0
25GNDGround
26GPIO7GPIOSPI0 CE1

Gotchas

4 known issues
  • Revision 1 and 2 GPIO differ. Three header pins changed between revisions: pin 3 and 5 are GPIO0/GPIO1 on revision 1 but GPIO2/GPIO3 on revision 2, and pin 13 is GPIO21 on revision 1 but GPIO27 on revision 2. Old tutorials often assume one or the other.[7]
  • ARMv6 only. The BCM2835 is ARMv6. Many Linux distributions only ship ARMv7 or 64-bit Arm builds, so use 32-bit Raspberry Pi OS.[5]
  • 3.3 V only. The GPIO pins are 3.3 V. Do not connect 5 V signals or components to them.[2]
  • Little current per pin. Each GPIO pin can supply up to about 16 mA and all pins together about 50 mA; drive motors and other loads through a transistor or driver board.[3]

What changed

From the specs

Next came the Raspberry Pi 1 Model B+

SpecRaspberry Pi 1 Model BRaspberry Pi 1 Model B+
RAM256 MB; 512 MB from October 2012512 MB
StorageFull-size SD cardmicroSD card
GPIO26-pin header (P1)40-pin header
USB2 × USB 2.04 × USB 2.0
VideoHDMI and RCA composite; DSI display connectorHDMI; composite on the 3.5 mm AV jack; DSI display connector
Dimensions85.6 × 56.5 mm—

Power and battery

3 facts
Recommended supply
1.2 A[3]
USB peripheral budget
500 mA[3]
Typical bare-board draw
500 mA[3]

Size and mechanical

1 facts
Board size
85.6 × 56.5 mm[5]

Revision 1 boards have no mounting holes; revision 2 added two.

Revisions

3 revisions
Revision 1.0
February 2012: 256 MB of RAM. The I2C pins on P1 are GPIO0 and GPIO1, and pin 13 is GPIO21.[7]
Revision 2.0
September 2012: I2C moved to GPIO2 and GPIO3, pin 13 became GPIO27, and mounting holes were added. Still 256 MB at first.[7]
Revision 2.0, 512 MB
October 2012: Memory doubled to 512 MB at the same price.[4]

History and use today

Editorial

History

Raspberry Pi was created by a UK charity to get children programming again. The Model B went on sale on 29 February 2012; demand crashed the distributors' websites, and it shipped with 256 MB of RAM until the 512 MB version replaced it at the same price in October 2012.[5]

Still useful for

Slow by modern standards and limited to 32-bit software, but fine for a headless sensor logger, a retro emulator for 8-bit systems, or learning GPIO basics with Python. Pick a Zero 2 W or Pi 4 for anything that needs a desktop or modern web browser.

Sources

7 sources
  1. Raspberry Pi hardware introduction (documentation source)
  2. GPIO and the 40-pin header, Raspberry Pi documentation (source)
  3. Power supplies, Raspberry Pi documentation (source)
  4. Model B now ships with 512MB of RAM, Raspberry Pi news
  5. Raspberry Pi, Wikipedia
  6. Raspberry Pi OS downloads, Raspberry Pi
  7. Upcoming board revision, Raspberry Pi news

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