> Complete documentation index: [llms.txt](/llms.txt). Markdown versions of all pages are available by appending `.md` to page URLs.

# Binho Pulsar: Firmware

> Which firmware the Binho Pulsar runs, which file to install, how to check and update it, and where its release notes are.

The Pulsar runs two pieces of software: the **bootloader**, which only installs firmware, and the **firmware** (the application), which does everything else.

## Latest firmware

The latest Pulsar firmware, its download and how to install it are in the [Latest Firmware table](/guides/firmware-updates/#latest-firmware). What changed in each version, and the known limitations, are in the [Firmware Release Notes](/releases/firmware-release-notes/).

## Which file to install

| File | For |
| ---- | --- |
| `pulsar-app-<version>.afx` | Pulsar, Airlock bootloader |
| `.gfi` | Pulsar, legacy bootloader |

:::danger
**Never load Supernova firmware on a Pulsar.** A cross-loaded image can leave the adapter unusable until it is recovered at the factory. Check the product name in the file name before copying it.

:::

## Which bootloader is installed

If the adapter runs firmware 4.3.0 or later, it has the **Airlock bootloader**: it takes `.afx` files and works with [dfu.binho.io](https://dfu.binho.io). Firmware 4.2.x and older runs on the **legacy bootloader**, which takes `.gfi` files and needs a one-time migration before it can run 4.3.0 or later.

To read the firmware version and tell the bootloaders apart, see [Check the Firmware and Bootloader](/guides/firmware-updates/#check-the-firmware-and-bootloader).

:::note
Mission Control 2.16.1 and earlier do not work with Pulsar firmware 4.x. Use [Mission Control 3](/software/mission-control/) for this adapter.

:::

## What depends on the firmware version

* I2C and SPI target mode need firmware 4.5.0 or later.
* RS-485 and CAN-FD need firmware 4.4.0 or later. See [Virtual COM Port Modes](/hardware/pulsar/protocols/#virtual-com-port-modes-rs-485-and-can-fd).
* Some behaviors differ before and after 4.6.2. See the [known limitations](/hardware/pulsar/troubleshooting/#known-limitations-firmware-46x).

## Update the firmware

There are three ways to install it:

* [In the browser, with dfu.binho.io](/guides/firmware-updates/#update-in-the-browser) (Chrome or Edge)
* [By drag and drop](/guides/firmware-updates/#update-by-drag-and-drop)
* [With PyCosmicSDK](/guides/firmware-updates/#update-with-pycosmicsdk)

An adapter on firmware 4.2.x or earlier needs the [one-time bootloader migration](/guides/firmware-updates/#one-time-bootloader-migration) first.

If the adapter shows up as a USB drive named **PULSAR**, or a firmware file is rejected, see [Firmware and Bootloader](/support/troubleshooting/firmware-and-bootloader/).